Postoperative Controversies in the Management of Free Flap Surgery in the Head and Neck

Hirudin enhances perforator flap survival: Clinical application report and mechanistic exploration

BACKGROUND AND PURPOSE

Hirudin, a potent anticoagulant, is used in traditional Chinese medicine (TCM) to treat thrombotic conditions and prevent postoperative thrombosis. Coagulation-related vascular complications are a common cause of perforator flaps failure. This study explores hirudin's potential to enhance flap growth by mitigating coagulation-related issues.

MATERIALS AND METHODS

Patients were divided into GroupⅠ(hirudin group) and GroupⅡ(control). Laboratory tests covered red blood cell count (RBC), hematocrit (HCT), platelet count (PLT), monocyte count (MONO), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), and D-Dimer. Clinical parameters, including capillary refill time (CRT), flap swelling, and survival status, were evaluated. Animal experiments used Sprague-Dawley (SD) rats to establish random skin flaps. The experimental side received hirudin injection, while the control side received saline. Flaps were photographed to calculate survival rate, and CD31 immunohistochemical (IHC) analysis was performed to calculate microvessel density (MVD).

RESULTS

The study, with 29 patients, found significant CRT differences between groups on postoperative days 2 and 6 (p = 0.027; p = 0.019), favoring GroupⅠ. Swelling severity varied significantly over time; GroupⅡhad more pronounced swelling. GroupⅠshowed superior flap growth with fewer complications, statistically significant (p = 0.033). Specific lab indicators (MONO, PT, and FIB) were significant at certain times. In animal experiments, the experimental side consistently had higher flap survival and slightly increased CD31 expression at various times, with higher MVD on days 2 and 6.

CONCLUSIONS

Hirudin enhances flap survival through diverse mechanisms, supporting its role as a complementary approach in perforator flap surgeries.

Second sensor to improve near-infrared spectroscopy flap monitor utility: A prospective study

OBJECTIVE

This study assesses whether use of continuous noninvasive near-infrared spectroscopy (NIRS) sensor on head and neck free flap (FF) with a second sensor on nonoperated tissue improves distinction between systemic hypoperfusion and FF compromise.

METHODS

Single-institution, prospective study of patients undergoing head and neck FF reconstruction from December 2018 to April 2020. FFs were continuously monitored using NIRS on a monitor paddle with a second (control) sensor on the shoulder. Crude StO2 and percent change in StO2 were compared between the FF and control sensors on each patient, and percent change and percent difference between the control and the monitor paddle were documented to assess for congruity. Sentinel events (e.g., hypotension and hematoma) were documented to assess the association with change in StO2. These events and timing of StO2 changes were noted to assess associations with change in StO2.

RESULTS

A total of 48 patients had complete data. Donor sites included 35 soft-tissue FFs and 13 fibula FFs. Average StO2 was 73.7 ± 5.5 for FFs and 71.4 ± 5.0 for control sensors. There were seven sentinel events during the study. At the time of the events, StO2 dropped significantly more for the FF than the control sensor (FF = 52.2% drop; control = 6.2% drop; p = .016). NIRS signal denoted change prior to changes in implantable arterial Doppler in all cases.

CONCLUSIONS

The addition of a second sensor when using NIRS as a primary modality for FF monitoring may improve distinction between FF compromise events and systemic hypoperfusion. By increasing accuracy of the monitor, there is a potential for decreased resident burden and decreased use of higher level of care nursing, which could reduce overall costs.

Prolonged operative time predicts postoperative deep venous thrombosis in head and neck cancer patients who undergo free flap reconstruction

Objective

This study sought to quantify the deep venous thrombosis (DVT) incidence in head and neck cancer (HNC) patients undergoing free tissue transfer and to identify independent predictors of postoperative DVT.

Materials and Methods

This is a cross-sectional study of the National Surgical Quality Improvement Program database from 2010 through 2020. The sample included all HNC surgical patients treated with free flap reconstruction. The study outcome was the presence of a DVT requiring treatment within 30 days of surgery. Univariate analyses were performed using chi-squared and independent t-tests. A multiple logistic regression model was created using all significant univariate predictors.

Results

A total of 3954 patients were identified, of whom 53 (1.3%) experienced a postoperative DVT. The only medical comorbidity associated with DVT was COPD (RR = 2.7 [1.3, 5.4]; p < .01). Operative time longer than 9 hours (RR = 1.9 [1.0, 3.2]; p = .04) and length of stay longer than 10 days (RR = 1.9 [1.1, 3.2]; p = .02) were associated with greater DVT rates. In the multivariate analysis, only COPD (p < .01) and operative time (p = .02) were independently associated with DVT risk. The presence of a DVT was found to increase the relative risk of readmission (RR = 2.1 [1.2, 3.6]; p < .01) and non-home disposition (RR = 2.4 [1.7, 3.5]; p < .01).

Conclusions

The incidence of DVT in HNC free flap patients was comparable to what has been reported in the general population of HNC surgery patients. Operative time >9 h and COPD history were independent risk factors for DVT in this subset of patients. Symptomatic DVTs necessitating treatment were accompanied by poorer post-hospitalization outcomes.

Level of Evidence

Level 3.

Versatility and outcomes of lateral arm free flap in head and neck reconstruction: a retrospective case series study of our experiences and innovations

OBJECTIVES

The Lateral Arm Free Flap (LAFF) offers advantageous features like variable thickness and minimal hair growth. LAFF is primarily used in orofacial and pharyngeal reconstructions, with limited reports on tracheal/esophageal applications. Also, the psychological prognosis and quality of life in patients with LAFF reconstruction are lacking.

METHODS

This retrospective case series presents outcomes of LAFF reconstruction for head and neck surgical defects which included 19 patients. The disease type, location of reconstruction, TNM staging, tumor size, chemoradiation status, anxiety, depression, quality of life and detailed perioperative information of the LAFF reconstruction surgery were presented in a descriptive pattern. Subgroup analysis was conducted using Mann-Whitney U and Pearson r test.

RESULTS

All 19 patients (100%) had a viable flap after surgery with 5 (26.3%) of them developed flap-related complication. Patients with oropharyngeal reconstruction were more likely to have lower anxiety and depression score and higher quality of life than those with below-oropharyngeal reconstruction. However, no significant p-value was generated in any subgroup comparison or correlation test. And the application of LAFF in esophageal and tracheal reconstruction was proved to be successful.

CONCLUSIONS

The lateral arm free flap exhibits remarkable versatility and multifunctionality, providing advantageous outcomes in head and neck reconstruction.

LEVEL OF EVIDENCE

Level 4 according to OCEBM.

Effect of Perioperative Antithrombotics on Postoperative Transfusion and Hematoma in Head and Neck Free Flaps

Objective

To explore if antiplatelet or anticoagulant therapy increases the risk of transfusion requirement or postoperative hematoma formation in patients undergoing microvascular reconstruction for head and neck defects.

Study Design

Retrospective cohort study.

Setting

Departments of Otolaryngology-Head and Neck Surgery at the University of Alabama at Birmingham, the University of Colorado, and the University of California Irvine.

Methods

A multi-institutional, retrospective review on microvascular reconstruction of the head and neck between August 2013 to July 2021. Perioperative antithrombotic data were collected to examine predictors of postoperative transfusion and hematoma.

Results

A total of 843 free flaps were performed. Preoperative hemoglobin, hematocrit, operative time, and flap type were positive predictors of postoperative transfusion in both bivariate (P < .0001) and multivariate analyses (P < .0001). However, neither anticoagulation nor antiplatelet therapy were predictive of postoperative transfusion rates and hematoma formation.

Conclusion

Antithrombotic regimens do not increase the risk of postoperative transfusion or hematoma in head and neck microvascular reconstruction. Based on this limited data, perioperative antithrombotic regimens can be considered in patients who may otherwise be at risk for these postoperative complications.

Prosthetic Management of Flap-Related Complications Following Glossectomy in Locally Advanced Tongue Cancer

Total glossectomy defects resulting from postoncologic resection are commonly reconstructed with locoregional or free flaps. However, effectively managing complications that may arise after reconstruction can be a significant challenge. We present a unique case series describing prosthetic management of flap-related complications following glossectomy in patients treated for locally advanced tongue cancer. Three patients underwent total glossectomy, neck dissection, reconstruction using free flap, and tracheostomy. Two patients developed an intraoral fistula located in the anterior region of the floor of the mouth. The third patient developed a flap failure requiring a second procedure using a pectoralis major myocutaneous flap for correction of the orocutaneous fistula that ultimately did not heal. Mandibular obturator prostheses lined with a soft liner were fabricated for all the patients, which helped reduce salivary incontinence and improve swallowing and speech. This case series highlights that a collaborative interdisciplinary team approach is crucial for optimizing postoperative function and outcomes when managing complications from reconstructive procedures.

Practice Trends and Evidence-Based Practice in Microvascular Reconstruction

Microvascular and free flap reconstruction are important to the otolaryngology-head and neck surgery practice. Herein, the reader will find an up-to-date discussion of various evidence-based practice trends related to microvascular surgery, including surgical techniques, anesthetic and airway considerations, free flap monitoring and troubleshooting, surgical efficiency, and both patient-related and surgeon-related risk factors that may affect outcomes.

Postoperative depth of sedation and associated outcomes in free flap transfers to the head and neck

BACKGROUND

To evaluate the impact of postoperative depth of sedation in free flap transfers to the head and neck.

METHODS

A single center, retrospective cohort of 92 patients were stratified by depth of sedation, light sedation (RASS -1 or greater) or deep sedation (RASS less than -1), and analyzed for postoperative flap and medical complications.

RESULTS

Of the 92 patients 45 were included in the light sedation and 47 in the deep sedation group. Flap complication requiring return to the operating room occurred in 8 (22.2%) patients in light sedation compared to 12 (27.7%) (p = 0.450) patients in deep sedation. A composite outcome of flap and medical complications occurred less frequently in the light sedation group 14 (31.8%) compared to deep sedation 32 (69.6%) (p < 0.001).

CONCLUSION

There was no difference in return to the operating room between the two groups. Light sedation had reduced incidence of medical complications compared to deep.

Prevention of Venous Thromboembolism in Microvascular Surgery Patients Using Weight-Based Unfractionated Heparin Infusions

BACKGROUND

 Unfractionated heparin infusions are commonly used in microvascular surgery to prevent microvascular thrombosis. Previously, fixed-dose heparin infusions were believed to provide sufficient venous thromboembolism (VTE) prophylaxis; however, we now know that this practice is inadequate for the majority of patients. Anti-factor Xa (aFXa) level is a measure of unfractionated heparin efficacy and safety. This study evaluated the pharmacodynamics of weight-based dose heparin infusions and the impacts of real-time aFXa-guided heparin dose adjustments.

METHODS

 This prospective clinical trial enrolled adult microvascular surgery patients who received a weight-based heparin dose following a microsurgical procedure. Steady-state aFXa levels were monitored, and patients with out-of-range levels received dose adjustments. The study outcomes assessed were aFXa levels at a dose of heparin 10 units/kg/hour, time to adequate aFXa level, number of dose adjustments required to reach in-range aFXa levels, and clinically relevant bleeding and VTE at 90 days.

RESULTS

 Twenty-one patients were prospectively recruited, and usable data were available for twenty patients. Four of twenty patients (20%) had adequate prophylaxis at a heparin dose of 10 units/kg/hour. Among patients who received dose adjustments and achieved in-range aFXa levels, the median number of dose adjustments was 2 and the median weight-based dose was 11 units/kg/hour. The percentage of patients with in-range levels was significantly increased (65 vs. 15%, p = 0.0002) as a result of real-time dose adjustments. The rate of VTE at 90 days was 0%, and clinically relevant bleeding rate at 90 days was 15%.

CONCLUSION

 Weight-based heparin infusions at a rate of 10 units/kg/hour provide a detectable level of anticoagulation for some patients following microsurgical procedures, but most patients require dose adjustment to ensure adequate VTE prophylaxis.

Risk Factors for and Cost Implications of Free Flap Take-backs: A Single Institution Review

OBJECTIVE/HYPOTHESIS

For patients undergoing microvascular free tissue transfer (MFTT), we evaluated risk factors and financial implications of operating room (OR) take-back procedures.

STUDY DESIGN

Retrospective review at a tertiary care center.

METHODS

Patients who underwent MFTT for head and neck reconstruction from 2011 to 2018 were identified. We compared hospital length of stay and overall costs associated with OR take-back procedures. Multivariable regression analysis evaluated factors associated with OR take-backs during the same hospitalization.

RESULTS

A total of 727 free flaps were reviewed, and 70 OR take-backs (9.6%) were identified. Mean total length of stay (LOS) in the ICU was 3.4 days versus 6.7 days for non-take-back and take-back flaps, respectively (P < .001). Mean total LOS on the regular floor was 6.3 days versus 13.1 days, respectively (P < .001). This resulted in a cost differential of $33,507 (94.3% increase relative to non-take-back flaps). The total cost associated with an OR take-back was $39,786. Hematomas were the most common cause of take-backs and wound dehiscence was associated with the highest costs. On multivariable analysis, higher ASA class (OR, 2.06; 95% CI, 1.11-3.99; P = .026) and shorter ischemia times (OR, 0.52; 95% CI, 0.29-0.95; P = .030) were independently associated with increased risk of take-backs.

CONCLUSIONS

OR take-backs infrequently occur but are associated with a significant increase in financial burden when compared to free flap cases not requiring OR take-back. The large majority of the cost differential lies in a substantial increase of ICU and floor LOS for take-back flaps when compared to non-take-back flaps.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1821-E1829, 2021.

New techniques and recommendations in the management of free flap surgery for head and neck defects in cancer patients

Free flap surgery is the gold standard surgical treatment for head and neck defects in cancer patients. Outcomes have improved considerably, probably due to recent advances in surgical techniques. In this article, we review improvements in the parameters traditionally used to optimize hematocrit levels and body temperature and to prevent vasoconstriction, and describe the use of cardiac output-guided fluid management, a technique that has proved useful in other procedures. Finally, we review other parameters used in free flap surgery, such as clotting/platelet management and nutritional optimization.

Controversies in free tissue transfer for head and neck cancer: A review of the literature

BACKGROUND

Microvascular free tissue transfer provides superior functional outcomes when reconstructing head and neck cancer defects. Careful patient selection and surgical planning is necessary to ensure success, as many preoperative, intraoperative, and postoperative patient and technical factors may affect outcome.

AIMS

To provide a concise, yet thorough, review of the current literature regarding free flap patient selection and management for the patient with head and neck.

MATERIALS AND METHODS

PubMed and Cochrane databases were queried for publications pertaining to free tissue transfer management and outcomes.

RESULTS

Malnutrition and tobacco use are modifiable patient factors that negatively impact surgical outcomes. The use of postoperative antiplatelet medications and perioperative antibiotics for greater than 24 hours have not been shown to improve outcomes, although the use of clindamycin alone has been shown to have a higher risk of flap failure. Liberal blood transfusion should be avoided due to higher risk of wound infection and medical complications.

DISCUSSION

There is a wide range of beliefs regarding proper management of patients undergoing free tissue transfer. While there is some data to support these practices, much of the data is conflicting and common practices are often continued out of habit or dogma.

CONCLUSION

Free flap reconstruction remains a highly successful surgery overall despite as many different approaches to patient care as there are free flap surgeons. Close patient monitoring remains a cornerstone of surgical success.

Perioperative Care of Free Flap Patients

Microvascular free tissue transfer is an indispensable reconstructive option in head and neck reconstruction. Flap failure is relatively rare, but it is nonetheless very morbid and psychologically devastating to patients when it does occur. Further, complications after free tissue transfer to the head and neck remain common. There are numerous ongoing debates about various facets of preoperative, intraoperative, and postoperative care of patients undergoing free flap reconstruction of the head and neck, all ultimately searching for the optimal treatment algorithm to further improve flap success, minimize complications, and maximize patient outcomes. Herein, the authors review current literature surrounding optimal preoperative nutritional support, intraoperative vasopressor use, perioperative fluid management, use of antithrombotic agents, antibiotic use, and other facets of the care of head and neck free flap patients to provide a guide to surgeons.

Current practices in microvascular reconstruction in otolaryngology-head and neck surgery

OBJECTIVES/HYPOTHESIS

Despite major advances in the field of head and neck microvascular free tissue transfer (MFTT) over the past several decades, there are no standardized perioperative regimens for the care of patients undergoing free flap reconstructive surgery, and continued variation in practice exists. This study aimed to report current trends in the field of MFTT performed by otolaryngologists, including surgeon training, institutional operative practices, and perioperative management.

STUDY DESIGN

Cross-sectional survey.

METHODS

A survey of Accreditation Council for Graduate Medical Education-accredited residency programs and American Head and Neck Society fellowship sites was conducted.

RESULTS

Seventy-one (62.8%) programs responded, with 67 (94.4%) routinely performing MFTT and 23 (32.4%) having a dedicated microvascular fellowship program. Of institutions performing MFTT, 66 (98.5%) reported the use of a two-surgeon team, most commonly both otolaryngologists (76.3%). Institutional MFTT volumes and donor site frequency are reported. Postoperative care includes routine admission to the intensive care unit (75.2%), step-down unit (15.0%), or general care floor (8.1%). Postoperative flap monitoring practices, including modalities, personnel, and timing/frequency show institutional variation. Despite differences in postoperative monitoring regimen and management (sedation, anticoagulation, antibiotic use), surgeon-reported measures of flap success rate (95.7%, standard deviation [SD] 4.7%) and complication rate (6.8%, SD 2.4%) show little difference across institutions.

CONCLUSIONS

Many elements of MFTT perioperative care show continued variation at an institutional level. There is a notable shift toward the two-team approach within otolaryngology. Self-reported flap complication and success rates showed no significant differences based on perioperative care and monitoring regimen. Further study of perioperative practices should focus on standardization of care to improve overall outcomes in this complex patient population.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:138-145, 2019.

Perioperative considerations in free flap surgery: A review of pressors and anticoagulation

Given the high stakes for microvascular reconstruction, the majority of reconstructive surgeons have developed paradigms for pre, intra, and postoperative management that have proven to result in individual high success rates. Much has been done to identify and avoid perioperative factors that could potentially increase flap failure rates. Two example of this practice has been the generalized use of anticoagulation in free tissue transfer and the prohibition against vasopressor use in patients that are undergoing free tissue transfer. This manuscript will discuss these issues.

Head and Neck Reconstructive Surgery

Head and neck reconstruction following surgical extirpative management of head and neck cancer requires critical assessment and meticulous correction of both aesthetic and functional deficits to optimize the physical and psychological well-being of the patient. Unique to head and neck cancers is the potential alteration of one's senses, breathing, speech, and swallowing functions, as well as overall head and neck aesthetics. When possible, tissue defects are replaced with similar tissues, though donor sites may be anatomically local, regional, or distant. The "reconstructive ladder" provides a heuristic approach to restoring the functional and aesthetic integrity of the head and neck cancer patient. Local tissue-rearrangement, grafts, flaps, and prosthetics are all options in the armamentarium of the reconstructive surgeon. The aim of this chapter is to familiarize the reader with the aims of reconstructive surgery, techniques employed to restore form and function as well as challenges and outcomes.