Anesthesia and perioperative considerations for patients undergoing free tissue reconstruction of the oral cavity: a narrative review

Introduction

Background

Oral cavity squamous cell carcinoma (OSCC) is the most common malignant neoplasm and accounts for more than 90% of malignancies that occur in the oral cavity (1). Surgical excision is the standard upfront treatment in the absence of metastatic distant disease. For advanced staged OSCC, ablative surgery often results in a composite defect requiring a microvascular free tissue transfer (MFTT) reconstruction. MFTT is defined as the transfer of autogenous tissue transition with vascular supply from one anatomical site to another and is indicated when reconstructive options such as local and regional flaps are unable to provide adequate tissue bulk. MFTT success rates have consistently been reported to be as high as 95% due to technical improvements and monitoring modalities and serve as a reliable treatment option for composite oral cavity reconstruction (2,3).

Rationale and knowledge gap

While surgical techniques have improved in recent decades, complications following MFTT still exist; thus, preoperative, intraoperative, and postoperative optimization are imperative to ensure a successful surgical outcome. Currently, there does not exist a general consensus on a treatment algorithm for the perioperative management of head and neck patients undergoing MFTT of the oral cavity.

Objective

In this narrative review, the authors will review and highlight the perioperative anesthesia considerations for this patient population to guide both the surgeon and anesthesiologist/anesthetist. This could be helpful for institutions to set up their own protocols from preoperative treatment through intraoperative and finally through postoperative treatment. We present this article in accordance with the Narrative Review reporting checklist (available at https://joma.amegroups.com/article/view/10.21037/joma-24-7/rc).

Methods

This is a narrative review performed by the authors based on the expert consensus statement by the Society for Head and Neck Anesthesia regarding the management of adult patients undergoing head and neck surgery and free tissue reconstruction in 2021 (4). An online review of scientific articles was performed using the medical databases PubMed and Google Scholar (Table 1). The search strategy involved several keywords and their combinations including: oral cavity, free flap transfer, microvascular surgery, anesthesia, perioperative medicine, oral cavity reconstruction, perioperative management, free flap reconstruction of oral cavity. The inclusion criteria were studies in English, literature relevant to the expert consensus, and relevance to our study. Duplicates were excluded. An initial review of the abstracts was completed to eliminate any articles unrelated to our aims of analyzing oral cavity reconstruction. After the initial review to eliminate studies not relevant to the topic and the exclusion of duplicates, the scientific articles regarding free flap reconstruction of the oral cavity and anesthesia in a 25-year period from 1999 to 2024 were analyzed.

Perioperative management of MFTT for oral cavity reconstruction

Preoperative considerations

Preoperative optimization of head and neck patients undergoing MFTT remains an important key to success. The overall goal is to improve the flap success rate, minimize complications, and maximize patient outcomes. To achieve this, multidisciplinary care is recommended.

Nutrition optimization

Over 60% of head and neck patients suffer from malnutrition (5). Malnutrition can adversely impact the immune system and inflammatory response, leading to impaired wound healing. Adequate perioperative nutrition is important for the body’s maintenance and recovery after surgery. As stated in the expert consensus statement, individualized preoperative nutrition can lead to a reduction in hospital stays, infection rates, and incidence of wound dehiscence (4). Therefore, all patients requiring MFTT for oral cavity reconstruction can benefit from a comprehensive preoperative nutritional assessment (6).

Objective measures of malnutrition are imperative in addressing nutritional deficiencies. Objective evaluation of perioperative nutrition includes clinical markers such as body mass index (BMI) and unintentional weight loss if present. Unintentional weight loss is defined as weight loss of >5% of the body weight within 1–3 months or >10% within 6 months and contributes to malnutrition (7). Another objective measurement of malnutrition shown to be reliable is the Patient-Generated Subjective Global Assessment (PG-SGA) and was described by Tsai et al. The authors found that malnutrition on the PG-SGA scale was shown to be an independent risk factor for postoperative complications in patients with OSCC (8). Furthermore, lower BMI, older age, higher PG-SGA score, lower serum albumin level, and longer hospitalization were also found to be associated with malnutrition. One study showed that pre-albumin levels are associated with poor outcomes in head and neck microvascular reconstruction surgeries (9). In addition to the PG-SGA scale, other quantitative markers such as the neutrophil-lymphocyte ratio (NLR), have been described to assess nutritional status and healing potential (10). Neutrophil lymphocyte can indicate a pathological state and normal values are 1–2 and any numbers above or below are abnormal. Therefore, preoperative BMI, unintentional weight loss, PG-SGA score, and NLR can serve as measures to guide nutritional optimization postoperatively and improve clinical outcomes. Poor nutritional status and intake can lead to wound healing complications. Therefore, to promote healing and maintenance, immuno-modulating diets have been described and implemented. Immunonutrition is a new area of study that involves delivering arginine along with other amino acids and nutrients such as omega-3 fatty acids, nucleotides and vitamins. For example, Vidal-Casariego et al. showed that postoperative complications occurred in 47.5% of subjects who received arginine-enriched immunonutrition when compared to 25.2% who did not receive this special formulation of immunonutrition. These complications included partial flap necrosis, hematoma, flap infection, ecchymosis, wound dehiscence fistula, pneumonia, electrolyte disturbance, hyperglycemia, dysphoria, renal dysfunction (11). Additionally, the length of stay was on average 2.8 days longer in the control group compared to the treatment group. Similarly, Rowan et al. showed that enhanced perioperative nutrition led to significant reductions in postoperative fistula formation and decreased length of stay (5). Of note, pharyngeal leak and fistula formation were the most common complications encountered in this study as well as previously published studies. A systematic review and meta-analysis by Vidal-Casariego et al. demonstrated similar findings including decreased hospital stay and decreased development of fistulas (11). In addition to poor nutrition, postoperative hemoglobin concentration was also shown to be related with increased complication rates (12). Different studies report different ranges for the hemoglobin to be above with a wide range of 7–10 g/dL; while this is true, the literature has mentioned that free flap patients should follow normal transfusion criteria (12). In review, the literature demonstrates the critical role of preoperative nutritional assessment and nutritional modification as appropriate to promote healing and decrease complication rates following MFTT of the oral cavity in head and neck patients.

Social history considerations

Tobacco use is a major risk factor for OSCC and has been well-studied in MFTT in the literature. The expert consensus stated that preoperative tobacco cessation is beneficial for this patient population as tobacco use is associated with impaired mucociliary clearance and endothelial damage (4). Kaplan et al. reviewed 126 subjects that underwent head and neck MFTT and found that tobacco smoking was associated with an increased risk of postoperative hematoma formation (13). Surprisingly, vascular perfusion and survival rates following MFTT were found to be similar in smokers and nonsmokers (14). Furthermore, additional studies have also shown that tobacco smoking alone is not an independent predictor for free flap survival (15,16).

While tobacco smoking alone may not directly impact MFTT success rates, preoperative tobacco cessation can provide positive health benefits to the patient. Persistent tobacco smoking during and after surgery has been associated with postoperative surgical complications and can increase cardiopulmonary complications such as increased airway reactivity during general anesthesia. As mentioned formerly, tobacco smoking can impair mucociliary clearance, damage the endothelium causing atherosclerosis, and increase oxidative stress in the body (17). Complications associated with smoking include prolonged care in the intensive care unit (ICU), increased risk for pneumonia as well as increased hypercoagulability that could lead to flap perfusion, wound dehiscence, cardiopulmonary collapse, and sepsis. In a study by Crippen et al., tobacco smoking was found to be an independent factor for wound breakdown and reoperation within 30 days in subjects undergoing head and neck MFTT (18). Therefore, tobacco smoking prevention and cessation before surgery is an important predictor of wound healing and overall flap success rates. Previous studies have shown that tobacco smoking cessation as close as 2 weeks before surgery can reduce the risk for complications to that of nonsmokers (17).

Alcohol use is another common risk factor for OSCC, especially when in conjunction with tobacco smoking. Alcohol screening is an important component of the preoperative evaluation of head and neck patients, as untreated alcohol withdrawal can lead to fatal complications such as delirium tremens, electrolyte imbalances, malnutrition, cardiopulmonary abnormalities, and dehydration (19). Early detection and treatment of alcohol withdrawal syndrome reduces the risk for adverse outcomes in this population. Chronic users of alcohol generally experience withdrawal symptoms within a few days of sobriety (4). Gallivan and Reiter looked at subjects who underwent MFTT for mandibular reconstruction and found that those who had postoperative delirium treatments (DTs) had a lower flap survival rate of 25% (20).

Those who did not have postoperative DTs had a flap survival rate of 85% (20). Similarly, Crawley et al. found that subjects who were chronic alcohol users were 3.7 times more likely to experience acute alcohol withdrawal which was strongly associated with free flap failure in head and neck reconstruction (21). Accurate and detailed documentation of the social history is important before MFTT. When acute alcohol withdrawal is anticipated, pharmacologic protocols such as the Clinical Institute Withdrawal Assessment of Alcohol (CIWA) must be set in place to prevent DTs along with the formerly mentioned complications.

Preoperative education

Patient education is an essential but often underemphasized aspect in surgical planning for the MFTT patient. In addition to this, comprehension of all the information regarding the surgery remains the most difficult task for patients (22). This is also the time to provide education on behavioral risk factors such as tobacco smoking and alcohol use and discussion methods for cessation. Additionally, discussion of the postoperative course should be discussed to help set patient expectations and improve not only their understanding but also psychosocial state. Health literacy among oral cancer patients also remains an obstacle as well (21). Turkdogan et al. showed that the use of multimedia platforms such as animated surgical videos has increased more recently as a promising mode to improve patient education and satisfaction prior to surgery (22). As a result, improved understanding of the surgery before it happens has been shown to reduce patient anxiety before hospital admission. Following hospitalization, clinical anxiety and depression remained decreased for up to 3 and 6 months (22). Altogether, there is ongoing research to confirm whether preoperative education is associated with decreased hospital stays, shorter complication rates, and improved overall outcomes (23). Schmid et al. found an association with shorter length of stay, reduced complications, and decreased hospital costs with a preoperative Multi-Professional Assessment and Information Day (MUPAID) (24). Whether preoperative education for patients undergoing MFTT for oral cancer is associated with improved clinical outcomes remains to be seen.

Intraoperative considerations

Intraoperative management is important in maintaining the health of the free flap through airway management, flap perfusion and flap monitoring. Managing the flap perfusion creates its own complexities.

Factors impacting intubation

Airway management poses a unique challenge in oral cavity cancer reconstruction. The oral cavity is the anatomical entrance to the airway and plays a crucial role when working with free flap transfer for oral cavity cancer reconstruction. Mallampati is a classic assessment tool to analyze the relationship of the base of the tongue to the oropharyngeal opening. The Mallampati classification involves a four-point scale that assesses the position of the tongue relative to the size of the pharyngeal opening (25). Patients with oral cavity cancers that have Mallampati scores of 3 or 4 were associated with difficult tracheal intubation regardless of direct laryngoscopy or video laryngoscopy (25). In addition to this, any moderate edema in the hypopharyngeal and laryngeal sites can increase the difficulty of intubation. Other factors that could impact airway difficulty include previous radiation, limited maximal interincisal opening, extension of the tumor into the tongue causing immobility and/or increase in size and previous free flap surgery (26). Radiation fibrosis results from the combination of tonic contraction and fibrosis of the muscles of mastication as well as trismus and limited neck movement (26).

On the other hand, head and neck radiation in patients with oral cancer was not correlated with difficult tracheal intubation because flexible endoscopy can help overcome any difficulties. As technologies with video-based scopes improve, the ability to intubate will likely improve as well. Moore et al. showed that nasotracheal intubation (NTI) was a safe alternative to tracheostomy in select patients (26). They avoided NTI in patients with >50 tongue resection, significant for ethanol use, resection/defect near the junction with the oropharynx (26). Other studies have highlighted low complications rates with nasotracheal intubation (27). Nikhar et al. showed that awake fibreoptic remains the gold standard for difficult airways (28). Ledderhof et al. reported that adverse airway events within 30 days postoperatively occurred more in composite resections involving the floor of mouth with bilateral neck dissection and MFTT (29). As a result, this population should be considered for prophylactic tracheostomy. There was a prevalence of 15.4% of airway complications in this patient population (29). Overall, it is important to evaluate the type of resection and free flap reconstruction for the oral cavity and to also have a back-up plan as well if intubation proves to be difficult.

Vasopressors

General anesthesia impacts the hemodynamics of flap management during MFTT. Microvascular surgeons in the past were hesitant to use vasopressors due to the potential risk of inducing vasoconstriction anastomosis and flap necrosis (30). The expert consensus stated vasopressors can be used to optimize hemodynamic management of the patient population (4). Given the length of free flap surgeries and associated blood loss, managing the main determinants of tissue perfusion, mean arterial pressure (MAP) and blood viscosity, is crucial.

Maintaining cardiac output during free flap surgery is equally important for free flap perfusion. Vasopressors, such as epinephrine and norepinephrine are useful to optimize cardiac function (31). The timing of free vasopressor administration during induction intraoperatively did not affect the microvascular anastomosis even with 2 hours of administration (32). Gardner et al. demonstrated no difference in the rate of reoperation in patients receiving vasopressors (33,34). Only 5% of all free-flap patients needed re-operation after continuous vasopressor usage. Taylor et al. showed that there was no significant difference between pressor-based and traditional protocol flap failure (34). Fang et al. showed that there were only 39/2,637 (1.48%) flap failures in their group that used vasopressors compared to 6/346 (1.73%) flap failures (35). Overall, vasopressors improve outcomes for free flaps and do not have negative effects on free flap outcomes. Goal-directed intraoperative vasopressor administration is important and a safe way to manage intraoperative MAPs without compromising free flap microvascular demands.

Optimal monitoring and fluid management

Free flap perfusion management can be challenging during surgery and requires optimal anesthetic plan by both the surgical and anesthesia team. Hypotension management and intraoperative hemodynamic monitoring are essential for free flap survival. The expert consensus states that optimal monitoring of this patient population involves the use of standard ASA monitors as well as temperature monitors and arterial lines (4). Standard monitoring includes electrocardiogram (ECG) leads, pulse oximetry, end-tidal carbon dioxide monitoring, possible invasive arterial monitoring, and blood pressure monitoring. Temperature monitoring is also important because hypothermia has been associated with partial or complete flap loss so maintaining higher operating room temperatures and avoiding use of cool intravenous fluids (36). Maintaining a MAP of at least 65 mmHg is ideal. Although there is no consensus or standardization, traditional ways to monitor hypotension and hemodynamics include heart rate and MAP. Urine output and fluid intake are other ways to monitor MAP. Urine output between 0.5 and 1.0 mL/kg/h is optimal (37). While hypotension can be treated with fluid boluses and vasopressors, it is optimal to have goal-directed fluid therapy (30).

Goal-directed fluid therapy has emerged as a strategy to improve fluid administration and flap perfusion (37). The expert consensus stated that fluid overload can increase flap failure (4). One study showed that a stroke volume variation (SVV) of >13% improved both cardiac index (CI) and stroke volume index (SVI) despite similar HR and MAP measurements (38). This suggests an alternative monitoring approach compared to traditional ways such as blood pressure analysis or arterial waveform analysis. There exists a fine balance between aggressive fluids versus inadequate fluids during surgery because excessive fluids can have negative consequences on the vitality of the free flap (39). Studies have compared colloid versus crystalloids and have shown no significant difference in outcomes (40,41). On the other hand, Pattani et al. note that intraoperative administration of greater than 7 L of crystalloid during surgery increased major medical complications and free flap complications (42). Tapia et al. describe a goal-directed therapy algorithm that led to lower complication rates, and lower length of hospital stay (43). Moreover, they showed that the use of colloids and vasopressors did not affect flap prognosis and showed that colloids and crystalloids have different pharmacokinetics and target compartments (43). On the other hand, metabolic disturbances have been shown in excessive crystalloid administration (44). Regardless of the type of fluid administered, fluid resuscitation needs to be monitored intraoperatively because there is an increased risk of flap failure with prolonged surgeries. The development of goal-directed fluid therapy has decreased postoperative risks and ICU stays (43).

Furthermore, pain is an important factor to consider intraoperatively. The drugs affecting pain management can also affect cardiovascular hemodynamics and must be considered. Drugs like propofol induce hypotension. While this is true, propofol has been shown to reduce pulmonary complications for patients undergoing MFTT (45). A randomized controlled trial in 2016 showed that sevoflurane can potentially reduce ischemia reperfusion injury (46). Analgesia can be obtained with epidural or local perineural catheter. Dexmedetomidine has been shown to be safe in free flap and can prevent postoperative agitation (47,48). Therefore, it is important to determine a pain and anesthesia regimen that optimizes intraoperative conditions.

Hematocrit

Hematocrit is an important part of operative management for optimizing tissue oxygenation. The expert consensus states that the hematocrit should be maintained at or above 25 which would optimize oxygen delivery (4). Previous papers have tired a hematocrit of 30 as needing postoperative blood transfusion but Rossmiller et al. showed that a postoperative transfusion of hematocrit of <25 decreases blood transfusion rates without increasing complications (49). Postoperative transfusion at the threshold of 25 also decreases the need for postoperative blood transfusion (49). Transfusions during the perioperative period were not negative predictors of flap success rate. Perioperative lowest Hb level and age were predictors of flap failure (50).

Postoperative considerations

Postoperative management involving improvement of safety and outcomes remains a goal of postoperative care. Microvascular free flaps must be monitored while also maintaining the health of the patient as well.

Postoperative airway

Postoperative management of patients undergoing free flap reconstruction of the oral cavity has several aspects of patient care that need to be managed. One consideration needs to be postoperative management of the airway. When operating on the oral cavity patient, the proximity of the surgery to the airway raises concerns on the need for tracheostomy after free flap reconstruction. As previously mentioned, elective tracheostomy is frequently performed with oral cavity free flap reconstruction. Tracheostomy provides a secure airway, allows ventilator management and reduces the risk of airway compromise. If a tracheostomy is not performed, a safe extubation plan needs to be included in postoperative care. Madgar et al. showed that tracheostomy had no increased benefit over intubation and commented that tracheostomy should be elective (51). A survey of patients who underwent tracheostomy after free flap reconstruction reported discomfort with the procedure and would avoid tracheostomy if possible (52). Endotracheal intubation with subsequent delayed extubation is a safe alternative to tracheostomy (53). Other studies have shown that tracheostomy increases hospitalization time and has complication rates between 4–45% (54). It is important for the surgeon and anesthesia team to decide before the surgery an appropriate plan for MFTT airway management.

Due to the proximity of the surgery to the airway and the possibility of postoperative swelling with free flap bulk, delayed extubation 24–48 hours with ventilator management is an alternative strategy for postoperative care. Both tracheostomy and delayed extubation have advantages and complications. Singh et al. in a study of maxillofacial reconstruction after free flap surgery, the tracheostomy group had longer hospital stays when compared to the delayed extubation group (55). In this paper, they conclude that elective tracheostomy is dependent upon the type of surgery. Tracheostomy is indicated in surgical cases involving oropharyngeal reconstruction as well as maxillofacial free flap reconstruction with bilateral neck dissection. Huang et al. showed that fewer patients returned to the operating room from the delayed extubation group concluding that delayed extubation can be a safe and effective alternative to tracheostomy (56). Currently, the literature requires more level 1 evidence in determining the best route for patients and what situations warrant a tracheostomy versus delayed extubation.

Postoperative free flap monitoring

Monitoring of the free flap remains a vital part of the postoperative period and requires intricate observation by surgeons, nurses and other personnel involved. This is mostly dependent upon institutional monitoring techniques and staff availability (57). Postoperative recovery protocols should include hemodynamic and flap monitoring, anticoagulation, and deep vein thrombosis (DVT) prophylaxis, analgesia, and antibiotic prophylaxis therapy (58).

Postoperative monitoring for vascular compromise is imperative for flap survival and the most critical time for acute complications typically occurs within the first 24 hours after surgery (59). Free flap survival depends on blood supply through the vascular pedicle and the microvascular vessels anastomosis site. Compromised flaps can result from vascular compromise, necrosis, hematoma, and wound dehiscence among other complications (60). Several techniques are used to monitor free flaps postoperatively. Primary examination involves a detailed physical exam including flap color, capillary refill, temperature, and rigidity to assess free flap viability. Secondary techniques are also common in free flap monitoring. The most common technique is using a Doppler sonography signal which can be used externally (pencil Doppler technique) or internally with an implantable device (61). Other devices such as Cook-Swartz dopplers are employed as well.

In addition to physical exam-free flap monitoring, anticoagulation prophylaxis is another option to potentially improve flap patency and prevent thrombus formation (62). Several pharmacologic therapies are used with the majority using aspirin, low-molecular-weight dextrans, unfractionated heparin, or low-molecular-weight heparin (63). The literature consensus is inconclusive on the benefit of anticoagulation with several studies showing no difference and equivalent outcomes (64-66). Additional research is needed to determine optimal anticoagulation strategies for maximizing postoperative anticoagulation prophylaxis.

Postoperative pain management

Postoperative pain is complex and there are several strategies for pain management after major oral reconstruction. Since opioids are associated with the risk of dependence and severe side effects, research into multimodal pain has been well versed. The expert consensus stated that multimodal pain management may enhance pain control in this population (4). Studies have shown that multimodal pain control (MMPC) is a solution to help reduce postoperative opioid dependence (67). MMPC uses several pharmacological agents to target neurobiological pain pathways to reduce or even eliminate narcotic consumption (68). The most commonly used medications are nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, anticonvulsants, steroids, 1–2 agonists, NMDA antagonists, and local anesthetics (69).

Local and regional anesthesia techniques are safe and lead to decreased opioid utilization (70). These techniques involved administration by either a single injection or by catheter-based infusion either intermittently or continuously. Long-acting anesthetics such as bupivacaine, levobupivacaine, and ropivacaine among others have a prolonged duration of analgesia. These techniques in head and neck surgery have been analyzed by small cohort studies. Ferri et al. found significant pain reduction when using a mini catheter with a bolus of chirocaine at the donor site in the early postoperative period (71). Le et al. reported that total oral morphine equivalent utilization was significantly less in the presurgical and preregional anesthesia block compared to the control group (70). While MMPC is an effective approach for surgical pain management, designing a strategy for perioperative pain should always be surgery-specific and patient-specific (72). By incorporating local and regional anesthesia techniques into perioperative protocols, patient outcomes regarding pain management will become optimized with less reliance on opioids.

Antibiotics

The use of antibiotics during MFTT in the oral cavity is a controversial topic within the community. The oral cavity does contain many polymicrobial gram-positive and gram-negative aerobic and anaerobic organisms with hypothetical potential for infection. Surgical site infections can cause wound breakdown and dehiscence, risk of free flap failure, and increased hospital stays. While the expert consensus does not offer guidelines on antibiotics, there is evidence that supports the use of antibiotic therapy following free flap surgery (73). Some studies suggest that 80% of patients who did not receive antibiotics prophylaxis develop a surgical site infection (74). Ampicillin-sulbactam has been studied and evidence supports its use for antibiotic prophylaxis postoperatively in head and neck free flap reconstructive surgery, but no definitive protocol is in place (75). The length of postoperative antibiotic therapy is also controversial. Some studies have shown no benefit for length of therapy greater than a 24-hour regimen (74,76). Other studies show no difference in long-term antibiotic therapy greater than 2 days versus less than 2 days (77). The use of antibiotic prophylaxis is highly dependent upon each institution’s surgeon. Further research is needed to establish a standardized guideline regarding antibiotics for MFTT.

Inpatient management

Postoperative management of oral cancer patients is important due to the complexity of flap management (78). The expert consensus states that postoperative care can be delivered in intensive care or a floor setting with skilled nursing and monitoring (4). Nationally, 75% of all free flap patients are admitted to the ICU postoperatively (70). There are benefits to ICU stay such as increased flap monitoring in a controlled environment and lower nursing-to-patient ratio. Patients left intubated will require admission to the ICU for ventilator management. Arshad et al. reported an increased length of stay of 1 day for ICU patients vs non-ICU patients (79). There was no difference in free flap failure in this study (79). Aponte-Ortiz et al. showed that the length of stay was increased and take-back surgery was increased in the ICU group, but major postoperative complications, early free-flap complications, and late free-flap complications were unchanged (78). Return to the operating room was likely related to being admitted to an ICU setting because the decision to send a patient to the ICU likely included the medical and surgical complexity of the patient. Another study showed that patients going to the floor were relatively safe as long as there were no cardiopulmonary issues because the major postoperative complications seen for free-flap patients were cardiopulmonary in nature (80).

Inpatient costs are an important consideration for the hospital and the patient undergoing MFTT. A large contributor to inpatient costs is the use of ICU monitoring. The long-term cost was higher by $6,540.76 for patients in the ICU than the general floor (78). This is likely related to the increased length of stay, increased monitoring, and a higher nurse-to-patient ratio as well. This expense can be important for patients who do not have insurance coverage leading to increased financial burden (78). Aponte-Ortiz et al. reported that immediately after surgery, the cost of stay was higher for floor patients because they recovered in the postoperative anesthesia care unit (PACU) longer to ensure stability before transfer (78).

Limitations

This narrative review has limitations that need careful review and consideration. The inclusion and exclusion criteria omitted articles that were not written in English which could have eliminated data and insight from other studies. The review’s scope was mostly confined to the major themes listed in the expert consensus mentioned throughout the review (4). Furthermore, many of the studies were not level 1 evidence represented by systematic reviews or meta-analysis but rather randomized control trials or quasi-experimental studies which represent level 2 and level 3 evidence. More level 1 evidence for preoperative management would strengthen the evidence found in this narrative review (4). The narrative review approach inherently could introduce subjective interpretations of the presented data as well.

Conclusions

Reconstruction of large intraoral defects presents a significant challenge due to the intricate management and extensive demands in the perioperative period. Recognizing the collaborative role of surgeons, anesthesiologists and nurses is integral to the success of MFTT. There is still much to be learned regarding the role of preoperative education and as technology improves, the intraoperative monitoring will likely improve accordingly. In this article, we present an extensive review of the current literature on anesthesia considerations for MFTT in the setting of oral cavity reconstruction. We reviewed important parts of the expert consensus as well as other critical portions of preoperative, perioperative, and postoperative care. Management of free flaps is a complex endeavor that requires considerations ranging from preoperative through postoperative care. This review will allow reconstructive surgeons and anesthesiologists to work together in developing optimal care for their patients, enhancing patients’ outcomes, and providing comprehensive perioperative care.

Acknowledgments

Funding: None.

Footnote

Reporting Checklist: The authors have completed the Narrative Review reporting checklist. Available at https://joma.amegroups.com/article/view/10.21037/joma-24-7/rc

Peer Review File: Available at https://joma.amegroups.com/article/view/10.21037/joma-24-7/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://joma.amegroups.com/article/view/10.21037/joma-24-7/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Chi AC, Day TA, Neville BW. Oral cavity and oropharyngeal squamous cell carcinoma--an update. CA Cancer J Clin 2015;65:401-21. [Crossref] [PubMed]
2. Copelli C, Tewfik K, Cassano L, et al. Management of free flap failure in head and neck surgery. Acta Otorhinolaryngol Ital 2017;37:387-92. [Crossref] [PubMed]
3. Moratin J, Zittel S, Horn D, et al. Free-Flap Reconstruction in Early-Stage Squamous Cell Carcinoma of the Oral Cavity-A Prospective Monocentric Trial to Evaluate Oncological Outcome and Quality of Life. J Clin Med 2023;12:4833. [Crossref] [PubMed]
4. Healy DW, Cloyd BH, Straker T, et al. Expert Consensus Statement on the Perioperative Management of Adult Patients Undergoing Head and Neck Surgery and Free Tissue Reconstruction From the Society for Head and Neck Anesthesia. Anesth Analg 2021;133:274-83. [Crossref] [PubMed]
5. Rowan NR, Johnson JT, Fratangelo CE, et al. Utility of a perioperative nutritional intervention on postoperative outcomes in high-risk head & neck cancer patients. Oral Oncol 2016;54:42-6. [Crossref] [PubMed]
6. Dort JC, Farwell DG, Findlay M, et al. Optimal Perioperative Care in Major Head and Neck Cancer Surgery With Free Flap Reconstruction: A Consensus Review and Recommendations From the Enhanced Recovery After Surgery Society. JAMA Otolaryngol Head Neck Surg 2017;143:292-303. [Crossref] [PubMed]
7. Nesemeier R, Dunlap N, McClave SA, et al. Evidence-Based Support for Nutrition Therapy in Head and Neck Cancer. Curr Surg Rep 2017;5:18. [Crossref] [PubMed]
8. Tsai YT, Lai CH, Huang TH, et al. Association of malnutrition with postoperative complication risk after curative surgery for oral cancer: Observational study. Medicine (Baltimore) 2020;99:e23860. [Crossref] [PubMed]
9. Shum J, Markiewicz MR, Park E, et al. Low prealbumin level is a risk factor for microvascular free flap failure. J Oral Maxillofac Surg 2014;72:169-77. [Crossref] [PubMed]
10. Maruyama Y, Inoue K, Mori K, et al. Neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as predictors of wound healing failure in head and neck reconstruction. Acta Otolaryngol 2017;137:106-10. [Crossref] [PubMed]
11. Vidal-Casariego A, Calleja-Fernández A, Villar-Taibo R, et al. Efficacy of arginine-enriched enteral formulas in the reduction of surgical complications in head and neck cancer: a systematic review and meta-analysis. Clin Nutr 2014;33:951-7. [Crossref] [PubMed]
12. Wang C, Fu G, Liu F, et al. Perioperative risk factors that predict complications of radial forearm free flaps in oral and maxillofacial reconstruction. Br J Oral Maxillofac Surg 2018;56:514-9. [Crossref] [PubMed]
13. Kaplan ED, Rozen WM, Shayan R, et al. Preventing postoperative haematomas in microvascular reconstruction of the head and neck: lessons learnt from 126 consecutive cases. ANZ J Surg 2008;78:383-8. [Crossref] [PubMed]
14. Ooms M, Puladi B, Houschyar KS, et al. Smoking and microvascular free flap perfusion in head and neck reconstruction: radial free forearm flaps and anterolateral thigh flaps. Sci Rep 2022;12:13902. [Crossref] [PubMed]
15. Lassig AAD, Bechtold JE, Lindgren BR, et al. Tobacco exposure and wound healing in head and neck surgical wounds. Laryngoscope 2018;128:618-25. [Crossref] [PubMed]
16. Ehrl D, Heidekrueger PI, Haas EM, et al. Does Cigarette Smoking Harm Microsurgical Free Flap Reconstruction? J Reconstr Microsurg 2018;34:492-8. [Crossref] [PubMed]
17. Grønkjær M, Eliasen M, Skov-Ettrup LS, et al. Preoperative smoking status and postoperative complications: a systematic review and meta-analysis. Ann Surg 2014;259:52-71. [Crossref] [PubMed]
18. Crippen MM, Patel N, Filimonov A, et al. Association of Smoking Tobacco With Complications in Head and Neck Microvascular Reconstructive Surgery. JAMA Facial Plast Surg 2019;21:20-6. [Crossref] [PubMed]
19. Weinfeld AB, Davison SP, Mason AC, et al. Management of alcohol withdrawal in microvascular head and neck reconstruction. J Reconstr Microsurg 2000;16:201-6. [Crossref] [PubMed]
20. Gallivan KH, Reiter D. Acute alcohol withdrawal and free flap mandibular reconstruction outcomes. Arch Facial Plast Surg 2001;3:264-6. [Crossref] [PubMed]
21. Crawley MB, Sweeny L, Ravipati P, et al. Factors Associated with Free Flap Failures in Head and Neck Reconstruction. Otolaryngol Head Neck Surg 2019;161:598-604. [Crossref] [PubMed]
22. Turkdogan S, Roy CF, Chartier G, et al. Effect of Perioperative Patient Education via Animated Videos in Patients Undergoing Head and Neck Surgery: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg 2022;148:173-9. [Crossref] [PubMed]
23. List MA, Knackstedt M, Liu L, et al. Enhanced recovery after surgery, current, and future considerations in head and neck cancer. Laryngoscope Investig Otolaryngol 2023;8:1240-56. [Crossref] [PubMed]
24. Schmid M, Giger R, Nisa L, et al. Association of Multiprofessional Preoperative Assessment and Information for Patients With Head and Neck Cancer With Postoperative Outcomes. JAMA Otolaryngol Head Neck Surg 2022;148:259-67. [Crossref] [PubMed]
25. Zheng G, Feng L, Lewis CM. A data review of airway management in patients with oral cavity or oropharyngeal cancer: a single-institution experience. BMC Anesthesiol 2019;19:92. [Crossref] [PubMed]
26. Moore MG, Bhrany AD, Francis DO, et al. Use of nasotracheal intubation in patients receiving oral cavity free flap reconstruction. Head Neck 2010;32:1056-61. [Crossref] [PubMed]
27. Mishra S, Bhatnagar S, Jha RR, et al. Airway management of patients undergoing oral cancer surgery: a retrospective study. Eur J Anaesthesiol 2005;22:510-4. [Crossref] [PubMed]
28. Nikhar SA, Sharma A, Ramdaspally M, et al. Airway Management of Patients Undergoing Oral Cancer Surgery: A Retrospective Analysis of 156 Patients. Turk J Anaesthesiol Reanim 2017;45:108-11. [Crossref] [PubMed]
29. Ledderhof NJ, Carlson ER, Heidel RE, et al. Are Tracheotomies Required for Patients Undergoing Composite Mandibular Resections for Oral Cancer? J Oral Maxillofac Surg 2020;78:1427-35. [Crossref] [PubMed]
30. Naik AN, Freeman T, Li MM, et al. The Use of Vasopressor Agents in Free Tissue Transfer for Head and Neck Reconstruction: Current Trends and Review of the Literature. Front Pharmacol 2020;11:1248. [Crossref] [PubMed]
31. Goh CSL, Ng MJM, Song DH, et al. Perioperative Vasopressor Use in Free Flap Surgery: A Systematic Review and Meta-Analysis. J Reconstr Microsurg 2019;35:529-40. [Crossref] [PubMed]
32. Kelly DA, Reynolds M, Crantford C, et al. Impact of intraoperative vasopressor use in free tissue transfer for head, neck, and extremity reconstruction. Ann Plast Surg 2014;72:S135-8. [Crossref] [PubMed]
33. Gardner JR, Gau V, Page P, et al. Association of Continuous Intraoperative Vasopressor Use With Reoperation Rates in Head and Neck Free-Flap Reconstruction. JAMA Otolaryngol Head Neck Surg 2021;147:1059-64. [Crossref] [PubMed]
34. Taylor RJ, Patel R, Wolf BJ, et al. Intraoperative vasopressors in head and neck free flap reconstruction. Microsurgery 2021;41:5-13. [Crossref] [PubMed]
35. Fang Q, Yuan J, Du W, et al. Orocutaneous Fistula Formation in Free Flap Reconstruction for Oral Squamous Cell Carcinoma. Front Oncol 2022;12:887118. [Crossref] [PubMed]
36. Goswami U, Jain A. Anaesthetic implications of free-flap microvascular surgery for head and neck malignancies - A relook. J Anaesthesiol Clin Pharmacol 2021;37:499-504. [Crossref] [PubMed]
37. Al Saied G, Almutairi HM, Alharbi Y, et al. Comparison Between the Impact of Vasopressors and Goal-Directed Fluid Therapy on the Management of Free Flap Reconstruction of Head and Neck and Monitoring in ICU. Cureus 2020;12:e12108. [Crossref] [PubMed]
38. Funk D, Bohn J, Mutch W, et al. Goal-directed fluid therapy for microvascular free flap reconstruction following mastectomy: A pilot study. Plast Surg (Oakv) 2015;23:231-4. [Crossref] [PubMed]
39. Vincent A, Sawhney R, Ducic Y. Perioperative Care of Free Flap Patients. Semin Plast Surg 2019;33:5-12. [Crossref] [PubMed]
40. László I, Janovszky Á, Lovas A, et al. Effects of goal-directed crystalloid vs. colloid fluid therapy on microcirculation during free flap surgery: A randomised clinical trial. Eur J Anaesthesiol 2019;36:592-604. [Crossref] [PubMed]
41. Grill FD, Wasmaier M, Mücke T, et al. Identifying perioperative volume-related risk factors in head and neck surgeries with free flap reconstructions - An investigation with focus on the influence of red blood cell concentrates and noradrenaline use. J Craniomaxillofac Surg 2020;48:67-74. [Crossref] [PubMed]
42. Pattani KM, Byrne P, Boahene K, et al. What makes a good flap go bad? A critical analysis of the literature of intraoperative factors related to free flap failure. Laryngoscope 2010;120:717-23. [Crossref] [PubMed]
43. Tapia B, Garrido E, Cebrian JL, et al. Impact of Goal Directed Therapy in Head and Neck Oncological Surgery with Microsurgical Reconstruction: Free Flap Viability and Complications. Cancers (Basel) 2021;13:1545. [Crossref] [PubMed]
44. Patel RS, McCluskey SA, Goldstein DP, et al. Clinicopathologic and therapeutic risk factors for perioperative complications and prolonged hospital stay in free flap reconstruction of the head and neck. Head Neck 2010;32:1345-53. [Crossref] [PubMed]
45. Chang YT, Lai CS, Lu CT, et al. Effect of Total Intravenous Anesthesia on Postoperative Pulmonary Complications in Patients Undergoing Microvascular Reconstruction for Head and Neck Cancer: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg 2022; Epub ahead of print. [Crossref] [PubMed]
46. Claroni C, Torregiani G, Covotta M, et al. Protective effect of sevoflurane preconditioning on ischemia-reperfusion injury in patients undergoing reconstructive plastic surgery with microsurgical flap, a randomized controlled trial. BMC Anesthesiol 2016;16:66. [Crossref] [PubMed]
47. Rajan S, Moorthy S, Paul J, et al. Effect of dexmedetomidine on postoperative hemodynamics and outcome of free flaps in head and neck reconstructive surgeries. Open Anesthesiol J 2016;10:12-7. [Crossref]
48. Yang X, Li Z, Gao C, et al. Effect of dexmedetomidine on preventing agitation and delirium after microvascular free flap surgery: a randomized, double-blind, control study. J Oral Maxillofac Surg 2015;73:1065-72. [Crossref] [PubMed]
49. Rossmiller SR, Cannady SB, Ghanem TA, et al. Transfusion criteria in free flap surgery. Otolaryngol Head Neck Surg 2010;142:359-64. [Crossref] [PubMed]
50. Kim MJ, Woo KJ, Park BY, et al. Effects of Transfusion on Free Flap Survival: Searching for an Optimal Hemoglobin Threshold for Transfusion. J Reconstr Microsurg 2018;34:610-5. [Crossref] [PubMed]
51. Madgar O, Livneh N, Dobriyan A, et al. Airway management following head and neck microvascular reconstruction: is tracheostomy mandatory? Braz J Otorhinolaryngol 2022;88:S44-9. [Crossref] [PubMed]
52. Rogers SN, Russell L, Lowe D. Patients' experience of temporary tracheostomy after microvascular reconstruction for cancer of the head and neck. Br J Oral Maxillofac Surg 2017;55:10-6. [Crossref] [PubMed]
53. Lewis R, Scott N, Fardy M. Head and neck surgery: tracheostomy or not? Br J Oral Maxillofac Surg 2017;55:567. [Crossref] [PubMed]
54. Patel PN, Valmadrid AC, Hong DY, et al. Immediate Use of Uncuffed Tracheostomy after Free Flap Reconstruction of the Head and Neck. Otolaryngol Head Neck Surg 2018;159:242-8. [Crossref] [PubMed]
55. Singh T, Sankla P, Smith G. Tracheostomy or delayed extubation after maxillofacial free-flap reconstruction? Br J Oral Maxillofac Surg 2016;54:878-82. [Crossref] [PubMed]
56. Huang S, Feng Y, Li S, et al. Application of delayed extubation for the free-flap reconstruction of oral and maxillofacial defects in patient with oral diseases. J Stomatol Oral Maxillofac Surg 2023;124:101527. [Crossref] [PubMed]
57. Patel UA, Hernandez D, Shnayder Y, et al. Free Flap Reconstruction Monitoring Techniques and Frequency in the Era of Restricted Resident Work Hours. JAMA Otolaryngol Head Neck Surg 2017;143:803-9. [Crossref] [PubMed]
58. Coyle MJ, Main B, Hughes C, et al. Enhanced recovery after surgery (ERAS) for head and neck oncology patients. Clin Otolaryngol 2016;41:118-26. [Crossref] [PubMed]
59. Varadarajan VV, Arshad H, Dziegielewski PT. Head and neck free flap reconstruction: What is the appropriate post-operative level of care? Oral Oncol 2017;75:61-6. [Crossref] [PubMed]
60. Qian Y, Li G, Zang H, et al. A Systematic Review and Meta-analysis of Free-style Flaps: Risk Analysis of Complications. Plast Reconstr Surg Glob Open 2018;6:e1651. [Crossref] [PubMed]
61. Kohlert S, Quimby AE, Saman M, et al. Postoperative Free-Flap Monitoring Techniques. Semin Plast Surg 2019;33:13-6. [Crossref] [PubMed]
62. Swartz JE, Aarts MC, Swart KM, et al. The value of postoperative anticoagulants to improve flap survival in the free radial forearm flap: a systematic review and retrospective multicentre analysis. Clin Otolaryngol 2015;40:600-9. [Crossref] [PubMed]
63. Spiegel JH, Polat JK. Microvascular flap reconstruction by otolaryngologists: prevalence, postoperative care, and monitoring techniques. Laryngoscope 2007;117:485-90. [Crossref] [PubMed]
64. Ashjian P, Chen CM, Pusic A, et al. The effect of postoperative anticoagulation on microvascular thrombosis. Ann Plast Surg 2007;59:36-9; discussion 39-40. [Crossref] [PubMed]
65. Chalian AA, Anderson TD, Weinstein GS, et al. Internal jugular vein versus external jugular vein anastamosis: implications for successful free tissue transfer. Head Neck 2001;23:475-8. [Crossref] [PubMed]
66. Ridha H, Jallali N, Butler PE. The use of dextran post free tissue transfer. J Plast Reconstr Aesthet Surg 2006;59:951-4. [Crossref] [PubMed]
67. Go BC, Go CC, Chorath K, et al. Multimodal Analgesia in Head and Neck Free Flap Reconstruction: A Systematic Review. Otolaryngol Head Neck Surg 2022;166:820-31. [Crossref] [PubMed]
68. Schwenk ES, Mariano ER. Designing the ideal perioperative pain management plan starts with multimodal analgesia. Korean J Anesthesiol 2018;71:345-52. [Crossref] [PubMed]
69. Rosero EB, Joshi GP. Preemptive, preventive, multimodal analgesia: what do they really mean? Plast Reconstr Surg 2014;134:85S-93S. [Crossref] [PubMed]
70. Le JM, Gigliotti J, Sayre KS, et al. Supplemental Regional Block Anesthesia Reduces Opioid Utilization Following Free Flap Reconstruction of the Oral Cavity: A Prospective, Randomized Clinical Trial. J Oral Maxillofac Surg 2023;81:140-9. [Crossref] [PubMed]
71. Ferri A, Varazzani A, Valente A, et al. Perioperative pain management after fibular free flap harvesting for head-and-neck reconstruction using mini-catheters to inject local anesthetic: A pilot study. Microsurgery 2018;38:295-9. [Crossref] [PubMed]
72. Busby EM, Weyh AM, Warrick MD, et al. Communication: Regional anesthesia perioperative analgesia for free flap reconstruction. J Plast Reconstr Aesthet Surg 2021;74:2392-442. [Crossref] [PubMed]
73. Johnson JT, Yu VL. Antibiotic use during major head and neck surgery. Ann Surg 1988;207:108-11. [Crossref] [PubMed]
74. Balamohan SM, Sawhney R, Lang DM, et al. Prophylactic antibiotics in head and neck free flap surgery: A novel protocol put to the test. Am J Otolaryngol 2019;40:102276. [Crossref] [PubMed]
75. Vila PM, Zenga J, Jackson RS. Antibiotic Prophylaxis in Clean-Contaminated Head and Neck Surgery: A Systematic Review and Meta-analysis. Otolaryngol Head Neck Surg 2017;157:580-8. [Crossref] [PubMed]
76. Liu SA, Tung KC, Shiao JY, et al. Preliminary report of associated factors in wound infection after major head and neck neoplasm operations--does the duration of prophylactic antibiotic matter? J Laryngol Otol 2008;122:403-8. [Crossref] [PubMed]
77. Khariwala SS, Le B, Pierce BH, et al. Antibiotic Use after Free Tissue Reconstruction of Head and Neck Defects: Short Course vs. Long Course. Surg Infect (Larchmt) 2016;17:100-5. [Crossref] [PubMed]
78. Aponte-Ortiz JA, Greenberg-Worisek AJ, Marinelli JP, et al. Cost and clinical outcomes of postoperative intensive care unit versus general floor management in head and neck free flap reconstructive surgery patients. Am J Otolaryngol 2021;42:103029. [Crossref] [PubMed]
79. Arshad H, Ozer HG, Thatcher A, et al. Intensive care unit versus non-intensive care unit postoperative management of head and neck free flaps: comparative effectiveness and cost comparisons. Head Neck 2014;36:536-9. [Crossref] [PubMed]
80. Panwar A, Smith R, Lydiatt D, et al. Vascularized tissue transfer in head and neck surgery: Is intensive care unit-based management necessary? Laryngoscope 2016;126:73-9. [Crossref] [PubMed]