Analysis of risk factors associated with microvascular free flap failure using a multi-institutional database

Catastrophic complications following microvascular free tissue transfer: A 10-year review of NSQIP data

INTRODUCTION

There is an absence of literature regarding the risks of catastrophic medical outcomes (CMOs) such as stroke, cardiac arrest, and pulmonary embolism in microvascular free tissue transfer. This study aims to determine the CMO and mortality rates, as well as risk factors, associated with microvascular reconstruction of the head and neck, extremity, and breast.

METHODS

This study uses data from the American College of Surgeons National Surgical Quality Improvement Program. Cases of microvascular free tissue transfer from 2012 to 2021 were analyzed to assess the 30-day rates of CMOs, including death, as well as associated risk factors.

RESULTS

Of the 22,839 included patients, 785 (3.44%) experienced 1043 CMOs, including 99 (0.43%) deaths. Pulmonary complications of prolonged respiratory failure and pulmonary embolism were the most common. Independent risk factors included age, male sex, underweight status, longer operation times, American Society of Anesthesiologists (ASA) class of III or above, wound classification other than clean, and underlying conditions such as diabetes, hypertension, chronic obstructive pulmonary disorder, dyspnea, metastatic cancer, and ventilator dependence. CMOs were associated with an average 10-day delay in hospital discharge. Multivariate regression analysis revealed that head and neck reconstructions were associated with increased risk of CMO (OR 4.96; p < 0.0001).

CONCLUSION

This is the largest study to examine CMOs following microvascular free tissue transfer. Compared to previous literature spanning the period between 2006 and 2011, we observed a decreased rate of CMOs but a slight increase in 30-day mortality. Our data provide updated and comprehensive criteria for risk stratification and patient counseling. The modifiable risk factors reported in our study should be considered in elective, non-urgent cases of microvascular reconstruction.

Rat Microvascular Model is Tolerant to Technical Errors

BACKGROUND

 Extensive studies have been conducted using the rat model to understand the potential technical errors that lead to anastomotic failure. However, current literature indicates that the rat model has excellent tolerance to diverse errors committed by microsurgeons. The error-investigating rat model is often created by one or two experienced surgeons, and only one isolated technical error is examined. These biases may potentially cause limitations of the results from previous studies. Meanwhile, venous anastomoses have rarely been investigated in previous literature. Therefore, it is important to elucidate this topic with a more comprehensive study design.

METHODS

 Ninety-four arterial and 94 venous anastomoses on Sprague-Dawley rat femoral vessels that were performed by 47 microsurgeons who participated in the microsurgery course at the Columbia University and the University of Thessaloniki were evaluated. In total, 10 technical errors were examined: (1) disruption of suture line, (2) back-wall stitch, (3) oblique stitch, (4) wide bite, (5) partial thickness bite, (6) unequal suture distance, (7) tear in vessel wall, (8) excessively tight suture, (9) suture threads in lumen, and (10) large edge overlap. The frequency of each error committed, and the 30-minute postoperative patency was also recorded. The underlying causal relationship between these errors, potential interaction, and the short-term anastomosis patency was analyzed statistically.

RESULTS

 Only the back-wall stitch was found to have a significant causal effect on arterial anastomosis failure (p < 0.001). Back-wall stitch, wide bite, and partial thickness bite significantly impact venous anastomosis patency (p < 0.001). No other statistically significant result was found.

CONCLUSION

 Overall, the rat model is highly resilient to various technical errors despite these mistakes being often considered clinically unacceptable. Therefore, researchers need to consider the resilience of the rat model when designing and analyzing future studies. In addition, microsurgery instructors should focus on individual stitch quality rather than the final patency.

Sex-Stratified Predictors of Prolonged Operative Time and Hospital Admission in Outpatient Parathyroidectomy

Our retrospective database study investigates sex-stratified predictors of prolonged operative time (POT) and hospital admission following parathyroidectomy for primary hyperparathyroidism (PHPT). The 2016 to 2018 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was queried for patients with PHPT undergoing parathyroidectomy. Cases analyzed were all outpatient status, arrived from home, coded as non-emergent, and elective. POT was defined by the 75th percentile. Hospital admission was defined as LOS ≥ 1 day. Univariate and multivariable binary logistic regressions were utilized. Of 7442 cases satisfying inclusion criteria, the majority were female (78.0%) and White (78.5%). Median OT (IQR) for females and males was 77 (58-108) and 81 (61-109) minutes, respectively (P = 0.003). 1965 (33.9%) females and 529 (32.3%) males required hospital admission. Independent predictors of POT included ASA class III/IV (aOR 1.342, 95% CI 1.007-1.788) and obesity (aOR 1.427, 95% CI 1.095-1.860) for males (P < 0.05). Independent predictors of hospital admission included age (aOR 1.008, 95% CI 1.002-1.014), ASA class III/IV (aOR 1.490, 95% CI 1.301-1.706), obesity (aOR 1.309, 95% CI 1.151-1.489), dyspnea (aOR 1.394, 95% CI 1.041-1.865), chronic steroid use (aOR 1.674, 95% CI 1.193-2.351), and COPD (aOR 1.534, 95% CI 1.048-2.245) for females (P < 0.05); and ASA class III/IV (aOR 1.931, 95% CI 1.483-2.516) and bleeding disorder (aOR 2.752, 95% CI 1.443-5.247) for males (P < 0.005). In conclusion, predictors of POT and hospital admission following parathyroidectomy for PHPT differed by patient sex. Identifying patients at risk for POT and hospital admission may optimize healthcare resource utilization. Level of Evidence: IV.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04444-3.

Free Flap Reconstruction of Sternal Defects after Cardiac Surgery: An Algorithmic Approach for Dealing with Sparse Recipient Vessels

Background

Sparsity of recipient vessels poses a challenge for microsurgical free flap reconstruction of sternal defects following deep sternal wound infection after cardiac surgery.

Methods

From January 2013, a standardized algorithm for dealing with sparse recipient vessels was strictly followed. In this retrospective study including 75 patients, we compared operative details, surgical complications, and reconstructive outcomes of patients treated according to this algorithm (group A: January 2013-May 2021; n = 46) with a historical control group (group B: January 2000-December 2012, n = 29).

Results

The left internal mammary artery had been harvested for arterial bypass grafting in 40 of 46 cases (87%) in group A and in all cases in group B. The right internal mammary artery (RIMA) and right internal mammary vein (RIMV) were the first choice as recipient vessels. In case of unsuitability of the RIMV, a right cephalic vein (CV) turndown was used for venous outflow. If both RIMA and RIMV proved insufficient, a single-stage arterio-venous loop (AVL) between the CV and subclavian artery (CV-SA AVL), CV and thoracoacromial artery (CV-TA AVL), or subclavian artery and subclavian vein (SA-SV AVL) was established. The algorithmic approach significantly reduced partial flap necrosis [group A: n = 3 (7%) versus group b: n = 7 (24%); P = 0.04], and overall operation time [group A: 360 ± 88 min versus group B: 415 ± 80 min; P = 0.01].

Conclusions

Standardized approaches improve clinical outcomes in microsurgical free flap sternal reconstruction after cardiac surgery.

The Perfect Timing-Immediate versus Delayed Microvascular Reconstruction of the Mandible

In this retrospective study, the clinical and economic implications of microvascular reconstruction of the mandible were assessed, comparing immediate versus delayed surgical approaches. Utilizing data from two German university departments for oral and maxillofacial surgery, the study included patients who underwent mandibular reconstruction following continuity resection. The data assessed included demographic information, reconstruction details, medical history, dental rehabilitation status, and flap survival rates. In total, 177 cases (131 male and 46 females; mean age: 59 years) of bony free flap reconstruction (72 immediate and 105 delayed) were included. Most patients received adjuvant treatment (81% with radiotherapy and 51% combined radiochemotherapy), primarily for tumor resection. Flap survival was not significantly influenced by the timing of reconstruction, radiotherapy status, or the mean interval (14.5 months) between resection and reconstruction. However, immediate reconstruction had consumed significantly fewer resources. The rate of implant-supported masticatory rehabilitation was only 18% overall. This study suggests that immediate jaw reconstruction is economically advantageous without impacting flap survival rates. It emphasizes patient welfare as paramount over financial aspects in clinical decisions. Furthermore, this study highlights the need for improved pathways for masticatory rehabilitation, as evidenced by only 18% of patients with implant-supported dentures, to enhance quality of life and social integration.

Race and Ethnicity Independently Predict Adverse Outcomes Following Head and Neck Autograft Surgery

OBJECTIVE

There is growing attention toward the implications of race and ethnicity on health disparities within otolaryngology. While race is an established predictor of adverse head and neck oncologic outcomes, there is paucity in the literature on studies employing national, multi-institutional data to assess the impact of race and ethnicity on head and neck autograft surgery.

METHODS

Using the National Surgical Quality Improvement Program (NSQIP) database, trends in 30 days outcomes were assessed. Patients with ICD-10 codes for malignant head and neck neoplasms were isolated. Autograft surgeries were selected using Current Procedural Terminology (CPT) codes for free flap and pedicled flap reconstruction. Primary outcomes included surgical complications, reoperation, readmission, extended length of stay and operation time. Each binary categorical variable was compared to racial/ethnic identity via binary logistic regression.

RESULTS

The study cohort consisted of 2447 patients who underwent head and neck autograft surgery (80.71% free flap reconstruction and 19.39% pedicled flap reconstruction). Black patients had significantly higher odds of overall surgical complications (odds ratio [OR] 1.583, 95% confidence interval [CI] 1.091, 2.298, p = 0.016) with much higher odds of perioperative blood transfusions (OR 2.291, 95% CI 1.532, 3.426, p = <.001). Hispanic patients were more likely to undergo reoperation within 30 days after surgery and were more likely to be hospitalized for more than 30 days post-operatively (OR 1.566, 95% CI 1.015, 2.418, p = 0.043 and OR 12.224, 95% CI 2.698, 55.377, p = 0.001, respectively).

CONCLUSIONS

Race and ethnicity serve as independent predictors of complications in the post-operative period following head and neck autograft surgery.

LEVEL OF EVIDENCE

III Laryngoscope, 2024.

The Value of a Co-surgeon in Microvascular Breast Reconstruction: A Systematic Review and Meta-analysis

Using a co-surgeon model has been suggested to improve perioperative outcomes and reduce the risk of complications. Therefore, we evaluated if a co-surgeon model compared with a single microsurgeon model could decrease the surgical time, length of stay, rate of complications, and healthcare-associated costs in adult patients undergoing microvascular breast reconstruction (MBR). A comprehensive search was performed across PubMed MEDLINE, Embase, and Web of Science. Studies evaluating the perioperative outcomes and complications of MBR using a single-surgeon model and co-surgeon model were included. A random-effects model was fitted to the data. Seven retrospective comparative studies were included. Ultimately, 1411 patients (48.23%) underwent MBR using a single-surgeon model, representing 2339 flaps (48.42%). On the other hand, 1514 patients (51.77%) underwent MBR using a co-surgeon model, representing 2492 flaps (51.58%). The surgical time was significantly reduced using a co-surgeon model in all studies compared with a single-surgeon model. The length of stay was reduced using a co-surgeon model compared with a single-surgeon model in all but one study. The log odds ratio (log-OR) of recipient site infection (log-OR = -0.227; P = 0.6509), wound disruption (log-OR = -0.012; P = 0.9735), hematoma (log-OR = 0.061; P = 0.8683), and seroma (log-OR = -0.742; P = 0.1106) did not significantly decrease with the incorporation of a co-surgeon compared with a single-surgeon model. Incorporating a co-surgeon model for MBR has minimal impact on the rates of surgical site complications compared with a single-surgeon model. However, a co-surgeon optimized efficacy and reduced the surgical time and length of stay.

Towards Optimizing Sub-Normothermic Machine Perfusion in Fasciocutaneous Flaps: A Large Animal Study

Machine perfusion has developed rapidly since its first use in solid organ transplantation. Likewise, reconstructive surgery has kept pace, and ex vivo perfusion appears as a new trend in vascularized composite allotransplants preservation. In autologous reconstruction, fasciocutaneous flaps are now the gold standard due to their low morbidity (muscle sparing) and favorable functional and cosmetic results. However, failures still occasionally arise due to difficulties encountered with the vessels during free flap transfer. The development of machine perfusion procedures would make it possible to temporarily substitute or even avoid microsurgical anastomoses in certain complex cases. We performed oxygenated acellular sub-normothermic perfusions of fasciocutaneous flaps for 24 and 48 h in a porcine model and compared continuous and intermittent perfusion regimens. The monitored metrics included vascular resistance, edema, arteriovenous oxygen gas differentials, and metabolic parameters. A final histological assessment was performed. Porcine flaps which underwent successful oxygenated perfusion showed minimal or no signs of cell necrosis at the end of the perfusion. Intermittent perfusion allowed overall better results to be obtained at 24 h and extended perfusion duration. This work provides a strong foundation for further research and could lead to new and reliable reconstructive techniques.

Effect of 2 Teams and Operative Time on Complications After Oral Cavity Free Flap Reconstruction

OBJECTIVE

Evaluate the effects of operative time and 2 team approach on complications after soft tissue free flap reconstruction for oral tongue cancer.

METHODS

Patients with oncologic glossectomy with myocutaneous or fasciocutaneous free flap reconstruction were included from the 2015 to 2018 American College of Surgery National Surgical Quality Improvement Program. The primary predictive variables assessed were operative time and 2 team approach; control variables included age, sex, body mass index (BMI), 5-question-modified frailty index (mFI-5), American Society of Anesthesiologists (ASA) class, and total work relative value units (wRVU). Outcomes assessed included 30-day mortality, 30-day reoperation, hospital length of stay beyond 30 days, readmission, medical and surgical complications, and non-home discharge. Multivariable logistic/linear regression models were used to predict surgical outcomes.

RESULTS

Microvascular soft tissue free flap reconstruction of the oral cavity after glossectomy was performed on 839 patients. Operative time was independently associated with readmission, prolonged length of stay, surgical complications, medical complications, and non-home discharge. A 2-team approach was independently associated with prolonged length of stay and medical complications. The mean operative time of the 1-team and 2-team approach was 8.73 and 9.13 hours. The 1-team approach did not significantly increase operative time (P = .16).

CONCLUSIONS

In the largest study to date of operative time on post-surgical outcomes after glossectomy and soft tissue free flap reconstruction, we found longer operative times increased rates of postoperative complications and non-home discharge. The 1-team approach is non-inferior to the 2-team approach with respect to operating time and complications.

The Impact of Transfer-Related Ischemia on Free Flap Metabolism and Electrolyte Homeostasis-A New In Vivo Experimental Approach in Pigs

Free flap tissue transfer represents the gold standard for extensive defect reconstruction, although malperfusion due to thrombosis remains the leading risk factor for flap failure. Recent studies indicate an increased immune response and platelet activation in connection with pathologic coagulation. The underlying cellular and molecular mechanisms remain poorly understood, however. The presented study, therefore, aims to investigate if transfer-related ischemia alters intra-flap metabolism and electrolyte concentrations compared to central venous blood after free flap transfer in pigs to establish a novel experimental model. Free transfer of a myocutaneous gracilis flap to the axillary region was conducted in five juvenile male pigs. The flap artery was anastomosed to the axillary artery, and intra-flap venous blood was drained and transfused using a rubber-elastic fixed intravenous catheter. Blood gas analysis was performed to assess the effect of transfer time-induced ischemia on intra-flap electrolyte levels, acid-base balance, and hemoglobin concentrations compared to central venous blood. Time to flap reperfusion was 52 ± 10 min on average, resulting in a continuous pH drop (acidosis) in the flaps' venous blood compared to the central venous system (p = 0.037). Potassium (p = 0.016), sodium (p = 0.003), and chloride (p = 0.007) concentrations were significantly increased, whereas bicarbonate (p = 0.016) and calcium (p = 0.008) significantly decreased within the flap. These observations demonstrate the induction of anaerobic glycolysis and electrolyte displacement resulting in acidosis and hence significant tissue damage already after a short ischemic period, thereby validating the novel animal model for investigating intra-flap metabolism and offering opportunities for exploring various (immuno-) thrombo-hemostatic issues in transplantation surgery.

Opioid-Free Anaesthesia Reduces Complications in Head and Neck Microvascular Free-Flap Reconstruction

Head and neck free-flap microvascular surgeries are complex and resource-intensive procedures where proper conduct of anaesthesia plays a crucial role in the outcome. Flap failure and postoperative complications can be attributed to multiple factors, whether surgical- or anaesthesia-related. The anesthesiologist should ensure optimised physiological conditions to guarantee the survival of the flap and simultaneously decrease perioperative morbidity. Institutions employ different anaesthetic techniques and results vary across centres. In our institution, two different total intravenous approaches have been in use: a remifentanil-based approach and a multimodal opioid-sparing approach, which is further divided into an opioid-free anaesthesia (OFA) subgroup. We studied every consecutive case performed between 2015 and 2022, including 107 patients. Our results show a significant reduction in overall complications (53.3 vs. 78.9%, p = 0.012), length of stay in the intensive care unit (3.43 ± 5.51 vs. 5.16 ± 4.23 days, p = 0.046), duration of postoperative mechanical ventilation (67 ± 107 vs. 9 ± 38 h, p = 0.029), and the need for postoperative vasopressors (10% vs. 46.6%, p = 0.001) in the OFA group (vs. all other patients). The multimodal and OFA strategies have multiple differences regarding the fluid therapy, intraoperative type of vasopressor used, perioperative pathways, and various drug choices compared to the opioid-based technique. Due to the small number of cases in our study, we could not isolate any attitude, as an independent factor, from the success of the OFA strategy as a whole. Large randomised controlled trials are needed to improve knowledge and help define the ideal anaesthetic management of these patients.

A Retrospective Matched-Pair Analysis of Long-term Outcomes after Successful Lower Extremity Free Flap Salvage

BACKGROUND

 Pedicle occlusion with total free flap loss after microvascular lower extremity reconstruction is a considerably rare yet devastating complication. Fortunately, in the majority of cases, emergency salvage takebacks of compromised free flaps are initiated in a timely manner. In this report, we present our analysis of long-term outcomes following transient vascular compromise mitigated through successful free flap salvage in the lower extremity.

METHODS

 We performed a single-center retrospective matched-pair analysis of 46 patients with lower extremity free flap reconstructions. Cases underwent successful revisions of microvascular compromise (n = 23), whereas controls had uneventful postoperative courses (n = 23). Patient-reported outcome questionnaires and physical evaluations were used to assess general quality of life, functional outcomes, and cosmesis (Lower Extremity Functional Scale [LEFS], Lower Limb Outcomes Questionnaire [LLOQ], Short Form 36 (SF-36), Vancouver Scar Scale [VSS]). The mean follow-up time was 4.4 years.

RESULTS

 The health-related quality of life assessed by the SF-36 did not differ significantly between both groups in any of the subscales (p ≥ 0.15 for all subscales). Functional outcomes did not show significant differences between both groups according to the LEFS (p = 0.78) and LLOQ (p = 0.45). The overall scar appearance assessed by the VSS showed significantly poorer cosmesis in the re-exploration group (p = 0.014).

CONCLUSION

 Salvage of compromised free flaps in the lower extremity yields similar long-term outcomes compared to noncompromised free flaps with regard to function and quality of life. However, free flap revisions may lead to impaired scar formation. This study provides further evidence that the opportunity for urgent re-exploration is indispensable.

Effect of operative time on complications associated with free flap reconstruction of the head and neck

OBJECTIVE

To evaluate whether prolonged operative time is negatively associated with post-operative complications and length of stay in patients undergoing microvascular free flap reconstruction for complex head and neck defects.

METHODS

342 consecutive patients undergoing microvascular reconstruction for head and neck defects between 2017-2019 at a single institution were evaluated. Operative outcomes and operative time were compared whilst controlling for patient and treatment related factors.

RESULTS

Mean operative time was 551 min and length of stay was 16.2 days. An 11% increase in the risk of a post-operative complication was observed for every additional hour of operative time (OR 1.11, 95% CI 1.03-1.21, p = 0.011) after adjusting for patient and treatment factors. A cut-off of 9 h yielded a 92% increase in complications on either side of this (OR 1.92, 95% CI 1.18-3.13, p = 0.009). Increased operative time was also associated with increased length of stay and return to theatres, but not medical complications.

CONCLUSION

Prolonged operative time is significantly associated with increased surgical complications, length of stay and return to theatres when performing microvascular reconstructive surgery for head and neck defects.

Microvascular Gracilis Free Flap: Single and Double Innervation

Facial paralysis (FP) is a devastating condition that can lead to significant aesthetic, social, and emotional morbidities for patients. For some patients with FP, free gracilis muscle transfer (FGMT) is the best option for smile restoration. Masseteric-driven FGMT produces a reliable voluntary smile. Cross-face nerve graft-driven FGMT can produce a spontaneous smile, but this technique has higher failure rates. Early studies suggest dual-innervation FGMT can produce a spontaneous smile while maintaining the reliability of masseteric-driven procedures. Great care should be taken during FGMT surgery to minimize facial bulk and place medial inset sutures that create a natural-appearing smile.

Impact of smoking on donor site following rectus flap harvest for head and neck reconstruction

OBJECTIVES

The rectus abdominis myocutaneous free flap has been widely used as a reconstructive option in head and neck reconstruction with great success. Challenging the popular assumption, this study sought to examine the effects of smoking on donor site complications in this population.

METHODS

Multi-institution retrospective study of 103 patients (50 active smokers, 28 former and 25 never smoked).

RESULTS

Overall complication rate was 14.5 %. Hernia rate 4.8 %, evisceration 0 %, dehiscence 2.9 %, infection 6.7 %. Smoking history did not significantlly influence complication rates (chi square test, p = 0.33). Abdominal wall closure technique also did not influence the complication rate (chi square test, p = 0.58).

CONCLUSIONS

The rectus abdomonis myocutaneous free flap has an acceptable complication rate that does not appear to be influenced by smoking history. While patients should be counseled regarding smoking cessation, smoking habits should not delay treatment nor obviate consideration of rectus flap utilization.

Advantages of the scapular system in mandibular reconstruction

BACKGROUND

Fibula free flaps (FFF) are often considered the first choice for mandibular reconstruction, but scapular system free flaps (SFF) have increased in popularity due to versatility, donor site advantages, and patient factors.

METHODS

Retrospective chart review of patients undergoing mandibulectomy with FFF or SFF reconstruction from 2016 to 2021.

RESULTS

Hundred and seventy-six patients (FFF n = 145, SFF n = 31) underwent the aforementioned procedures. Mean FFF operative time was 9.47 h versus 9.88 for SFF (p = 0.40). Two-flap reconstructions required 12.65 h versus 10.09 for SFF with soft tissue (p = 0.002). Donor site complications were identified in 65.6% of FFF with skin grafting.

CONCLUSIONS

These findings suggest that SFF requires similar operative time and results in reduced donor site morbidity as compared to FFF. Supine, concurrent harvesting of SFF allows for single-flap harvest with significantly shorter operative time. SFF could be considered a primary option for mandible reconstruction for complex defects and in select patients.

Microvascular reconstructions in oral and maxillofacial surgery - Results of a survey among oral and maxillofacial surgeons in Germany, Austria, and Switzerland

This study aimed to evaluate the use of microvascular free flaps (MFF) in oral and maxillofacial surgery (OMFS) in Germany, Austria, and Switzerland. A dynamic online questionnaire, using 42-46 questions, was sent to OMF surgeons based in hospitals in Germany, Austria, and Switzerland. The questionnaire was evaluated internally and externally. Aside from general information, data were collected on organizational aspects, approaches, MFF types and frequency, presurgical planning, intraoperative procedures, perioperative medications, flap monitoring, and patient management. Participants mostly performed 30-40 MFF each year (11/53). Most stated that the COVID-19 pandemic did influence MFF frequency (25/53) to varying extents. Radial forearm flap was most frequently used (37/53), followed by ALT (5/53), and fibula flap (5/53). Primary reconstruction was performed by most participants (35/48). Irradiated bony transplants were mostly used for implant placement after 12 months (23/48). Most participants (38/48) used reconstruction plates, followed by miniplates (36/48), PSI reconstruction (31/48), and PSI miniplates (10/48). Regarding the postoperative use of anticoagulants, low-molecular-weight (37/48) and unfractioned heparins (15/48) were widely used, most often for 3-7 days (26/48). Clinical evaluation was mostly preferred for flap monitoring (47/48), usually every 2 h (34/48), for at least 48 h (19/48). Strong heterogeneity in MFF reconstructions in OMFS was found, especially regarding the timepoints of reconstruction, types of osteosynthesis, and postoperative MFF management. These findings provide the chance to further compare the different treatment algorithms regarding relevant MFF aspects, such as postoperative management. This could create evidence-based treatment algorithms that will further improve the clinical outcomes in MFF reconstructions.

Intraoperative Heparin Bolus and Postoperative Anticoagulation with Low Molecular Weight Heparin Increase Reliability of Microsurgical Free Flaps for Upper Extremity Reconstruction

BACKGROUND

 Microsurgery is an indispensable tool of upper extremity reconstruction addressing defect coverage and the restoration of function. Perioperative anticoagulation and antiplatelet therapy are controversially discussed with impact on microsurgical outcome, but without clear evidence. This study aims to evaluate the impact of perioperative anticoagulation and antiplatelet therapy in microsurgical upper extremity reconstruction.

METHODS

 All eligible patients treated with microsurgical upper extremity reconstruction between January 2000 and July 2014 were included in a comparative analysis to define a superior anticoagulation and antiplatelet regime in a retrospective study. Endpoints were all major complications (e.g., total flap loss, arterial and venous thrombosis) as well as minor complication.

RESULTS

 A total of 183 eligible free flaps to the upper extremity were transferred in 169 patients. Altogether, 11 arterial (6.0%) and 9 venous (4.9%) thromboses, 11 total flap losses (6.0%), and 16 cases with hematoma (8.7%) were detected. In the subgroup analysis, patients who did not receive any heparin intraoperatively (n = 21; 11.5%) had a higher rate of major complications (p = 0.001), with total flap loss being the most frequent event (p = 0.004). A trend was shown for intraoperative bolus administration of 501 to 1,000 units unfractionated heparin (UFH) intravenously to have the lowest rate of major complications (p = 0.058). Intraoperative administration of acetylsalicylic acid (n = 13; 8.1%) did not have any influence on the rate of major complications. Postoperative anticoagulation with continuous UFH intravenously (n = 68; 37.2%) resulted in more frequent complications (p = 0.012), for example, an increased rate of total flap loss (p = 0.02) and arterial thrombosis (p = 0.02).

CONCLUSION

 The results of the present study favor administration of 501 to 1,000 units UFH intravenously as an intraoperative bolus (e.g., 750 units UFH intravenously). Postoperative low molecular weight heparin subcutaneous application in a prophylactic dose given once or twice a day was associated with less complications compared with continuous infusion of UFH, although continuously applied UFH may reflect an increased risk profile.

Risk Factors for Free Flap Outcomes: A Retrospective Study of 318 Free Flaps for Head and Neck Defect Reconstruction

OBJECTIVES

This study was conducted to identify the risk factors for free flap outcomes in head and neck reconstruction.

METHODS

A retrospective review of 318 free flaps were used for head and neck reconstructions in 317 patients over seven years. The patient characteristics, surgical data, and flap outcomes were recorded. The impact of risk factors related on the outcomes of free flaps were analyzed using single and multivariate analysis.

RESULTS

For single factor analysis, 295 free flaps for the first reconstruction were included. Hypertension and the type of recipient vein are associated with venous thrombosis (P = .018, P = .047). Hypertension, type of free flap, recipient artery, and recipient vein were associated with the incidence of re-exploration (P = .009, P = .011, P = .017, P = .021). Hypertension had an obvious effect on the flap survival (P = .005). For multivariate analysis, hypertension (odds ratio = .166, 95% confidence interval: .043 - .636; P = .009) was a statistically significant risk factor for flap survival. For types of recipient artery and vein, selecting two venous anastomosis (one of IJVS and one of EJVS) had the minimum incidence of venous thrombosis (2.2%), and selecting facial artery, single vein (one of IJVS), and two veins (one of IJVS and one of EJVS) for anastomosis had lower incidence of re-exploration, which were 4.4%, 2.9%, and 6.0%, respectively (P < .05).

CONCLUSIONS

Risk factors as hypertension, type of free flap, recipient artery and vein should be paid more attention in the free flaps for head and neck reconstructions. We believe proper measures will lead to better results in head and neck reconstruction.

The Free Myocutaneous Tensor Fasciae Latae Flap—A Workhorse Flap for Sternal Defect Reconstruction: A Single-Center Experience

Introduction: Deep sternal wound infections (DSWI) after cardiac surgery pose a significant challenge in reconstructive surgery. In this context, free flaps represent well-established options. The objective of this study was to investigate the clinical outcome after free myocutaneous tensor fasciae latae (TFL) flap reconstruction of sternal defects, with a special focus on surgical complications and donor-site morbidity. Methods: A retrospective chart review focused on patient demographics, operative details, and postoperative complications. Follow-up reexaminations included assessments of the range of motion and muscle strength at the donor-site. Patients completed the Quality of Life 36-item Short Form Health Survey (SF-36) as well as the Lower Extremity Functional Scale (LEFS) questionnaire and evaluated aesthetic and functional outcomes on a 6-point Likert scale. The Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scales (POSAS) were used to rate scar appearance. Results: A total of 46 patients (mean age: 67 ± 11 years) underwent sternal defect reconstruction with free TFL flaps between January 2010 and March 2021. The mean defect size was 194 ± 43 cm2. The mean operation time was 387 ± 120 min with a flap ischemia time of 63 ± 16 min. Acute microvascular complications due to flap pedicle thromboses occurred in three patients (7%). All flaps could be salvaged without complete flap loss. Partial flap loss of the distal TFL portion was observed in three patients (7%). All three patients required additional reconstruction with pedicled or local flaps. Upon follow-up, the range of motion (hip joint extension/flexion (p = 0.73), abduction/adduction (p = 0.29), and internal/external rotation (p = 0.07)) and muscle strength at the donor-sites did not differ from the contralateral sides (p = 0.25). Patient assessments of aesthetic and functional outcomes, as well as the median SF-36 (physical component summary (44, range of 33 to 57)) and LEFS (54, range if 35 to 65), showed good results with respect to patient comorbidities. The median VSS (3, range of 2 to 7) and POSAS (24, range of 18 to 34) showed satisfactory scar quality and scar appearance. Conclusion: The free TFL flap is a reliable, effective, and, therefore, valuable option for the reconstruction of extensive sternal defects in critically ill patients suffering from DSWIs. In addition, the TFL flap shows satisfactory functional and aesthetic results at the donor-site.

Clinical and Radiological Safety of Retained Implantable Doppler Devices Used for Free Flap Monitoring

INTRODUCTION

Implantable Doppler devices are reliable adjuncts used for free flap monitoring. Occasionally, the probe/wire is not removed and remains in the soft tissues. The clinical safety of the retained probes and safety and compatibility with magnetic resonance imaging (MRI) have not been studied. We present a series of retained implantable Doppler probes examining clinic outcomes, safety and compatibility with MRI, and effect on MRI image quality.

METHODS

A retrospective review was conducted of patients who had an implantable Doppler device for free flap monitoring between July 2007 and August 2018. Routine post-operative imaging was reviewed for all patients to identify incidental findings of a retained probe. A subset of patients with retained implantable Doppler probes who underwent MRI was identified. Magnetic resonance images were reviewed to detect any degradation of image quality.

RESULTS

A total of 323 patients who had an implantable Doppler device placed were reviewed 18 (5.6%) patients were identified with a retained probe and were included in this study. Mean age was 49 years with mean follow-up of 34.4 months. One potential device-related complication occurred in 1 (5.6%) patient. A total of 32 MRI scans were performed in 8 patients with retained devices, including 6 patients who underwent a total of 21 MRIs of the surgical site. There were no complications related to the MRI scans, and we found no significant degradation of image quality.

CONCLUSION

Retained implantable Doppler probes were not associated with substantial adverse clinical outcomes nor affected MRI image quality of the surgical site.

Should Antiplatelet Therapy Be Withheld Perioperatively? The First Study Examining Outcomes in Patients Receiving Dual Antiplatelet Therapy in the Lower Extremity Free Flap Population

BACKGROUND

Antiplatelet agents are typically withheld perioperatively because of bleeding concerns. Dual antiplatelet therapy, such as aspirin and clopidogrel, has significant morbidity and mortality benefits in patients with ischemic heart disease or peripheral vascular disease. This study aims to evaluate the impact of perioperative dual antiplatelet therapy in the lower extremity free tissue transfer population.

METHODS

Lower extremity free tissue transfers performed by the senior author (K.K.E.) from 2011 to 2019 were retrospectively reviewed. Demographics, comorbidities, perioperative dual antiplatelet therapy, and free tissue transfer characteristics were recorded. Outcomes of interest included flap success, hematoma formation, blood transfusion requirements, and cardiac event occurrence.

RESULTS

One hundred ninety-five free tissue transfers were included. Median age at the time of free tissue transfer was 56.5 years. Median Charlson Comorbidity Index was 3. Thirty-four patients were on clopidogrel, which was either withheld (n = 20) or continued (n = 14) on the day of free tissue transfer. Incidence of blood transfusion was significantly higher in both the withheld and continued versus nonclopidogrel groups. Flap success was statistically equivalent between groups (withheld, 90.0 percent; continued, 92.9 percent; nonclopidogrel, 95.0 percent; p = 0.346). Cardiac events occurred most often in the continued group (21.4 percent) compared to the withheld (5.0 percent) and nonclopidogrel (0.6 percent) groups. On multivariate analysis, holding clopidogrel remained significant for increased odds of postoperative transfusion. The clopidogrel group was no longer significant for intraoperative transfusion.

CONCLUSIONS

Despite increases in volume of blood products transfused, free tissue transfer can be performed safely with perioperative dual antiplatelet therapy. Withholding dual antiplatelet therapy on the day of free tissue transfer was not associated with decreased intraoperative transfusion; thus, dual antiplatelet therapy can safely be continued throughout the operative course to minimize cardiovascular risk.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

A single-center retrospective comparison of Duplex ultrasonography versus audible Doppler regarding anterolateral thigh perforator flap harvest and operative times

INTRODUCTION

We reported on the superiority of preoperative Duplex mapping ("Duplex") over audible Dopplers ("Doppler") in anterolateral thigh perforator (ALT) free flaps for upper extremity reconstruction. To corroborate our findings on a larger cohort, we conducted this present study focusing on surgical efficiency and patient safety.

METHODS

150 consecutive ALT free flaps were divided into 65 cases of preoperative Duplex versus 85 Doppler controls. We first compared patient demographics, operative details, and defect and flap characteristics. We then assessed group differences in the number and course of perforators pursued intraoperatively, flap harvest and operative times, and donor-site complications. Additionally, the impact of the training level of the primary microsurgeon was evaluated.

RESULTS

Cases and controls were comparable regarding age (p = .48), sex (p = .81), ASA class (p = .48), and BMI (p = .90). Duplex was associated with an increased likelihood of raising flaps on one single dominant perforator of purely septal course and significant reductions of flap harvest (68 ± 10 min, p < .0001) and operative times (74 ± 16 min, p < .0001), regardless of the experience of the primary microsurgeon. There were strong negative linear correlations between preoperative Duplex and both the flap harvest and operative times (p < .0001). Additionally, while there was no effect on the emergency take-back rate (OR = 1.3, p = .60), revisions were significantly less likely among duplexed patients (OR = 0.15, p = .04).

CONCLUSIONS

Preoperative Duplex is associated with a significant reduction in ALT free flap harvest and overall operative times, as well as donor-site revisions as opposed to Doppler planning, regardless of the training level of the primary microsurgeon.

Risk Factors for 30-Day Mortality After Head and Neck Microsurgical Reconstruction for Cancer: NSQIP Analysis

Objective

To identify the incidence and risk factors for 30-day postoperative mortality after microsurgical head and neck reconstruction following oncological resection.

Study Design

Retrospective case-control study.

Setting

American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database.

Methods

Microsurgical head and neck reconstructive cases were identified from 2005 to 2018 using Current Procedural Terminology codes and oncologic procedures using the International Classification of Disease 9 and 10 codes. The outcome of interest was 30-day mortality.

Results

The 30-day postoperative mortality rate was 1.2%. Univariate logistic regression analysis identified the following associations: age >80 years, hypertension, poor functional status, preoperative wound infection, renal insufficiency, malnutrition, anemia, and prolonged operating time. Multivariable logistic regression models were used to stratify further by the degree of malnutrition and anemia. Hematocrit <30% was found to be an independent risk factor for 30-day postoperative mortality (odds ratio [OR] = 9.59, confidence interval [CI] 2.32-39.65, P < .1) with albumin <3.5 g/dL. This association was even stronger with albumin <2.5 g/dL (OR = 11.64, CI 3.06-44.25, P < .01). One-third of patients (36.6%) had preoperative anemia, of which less than 1% required preoperative transfusion, although one-quarter (24.6%) required intraoperative or 72 hours postoperative transfusion.

Conclusions

Preoperative anemia is a risk factor for 30-day postoperative mortality. This association seems to get stronger with worsening anemia. Identification and optimization of such patients preoperatively may mitigate the incidence of 30-day postoperative mortality.

Balancing Training Opportunities and Patient Outcomes: A Single Surgeon's Experience

ABSTRACT

Microvascular free tissue transfer is the criterion standard of reconstruction post-oncological resections of the head and neck region. We present a consultant's first 200 consecutive microvascular head and neck reconstructions in independent practice. A retrospective analysis of a prospectively collected database of all head and neck reconstructions performed in the first 3 years of practice was performed. These included 200 consecutive microvascular head and neck reconstructions performed by a single surgeon at a tertiary referral center. We review the results and complications in this series and discuss factors significant for successful outcomes in head and neck reconstruction. We also highlight that different parts of the surgery in the majority of cases were performed by a trainee under the supervision of the senior surgeon and thus discuss the need for training future plastic surgeons with an interest in head and neck reconstruction.

Evolution and Transformation of Uterine Transplantation: A Systematic Review of Surgical Techniques and Outcomes

BACKGROUND

 Uterine transplantation (UTx) is acknowledged to be on the second (2A) of five steps of development in accordance with the staging system for the evaluation of surgical innovations. Accordingly, we aimed to systematically review the available evidence of the surgical techniques and outcomes of UTx in terms of graft survival.

METHODS

 A comprehensive search was conducted across PubMed Medline, Cochrane-EBMR, Scopus, Web of Science, and CENTRAL through November 2020.

RESULTS

 Forty studies, reporting 64 recipients and 64 donors, satisfied inclusion criteria. The surgical time and the estimated blood loss were 515 minutes and 679 mL for graft procurement via laparotomy, 210 minutes and 100 mL for laparoscopic-assisted graft harvest, and 660 minutes and 173 mL for robotic-assisted procedures, respectively. Urinary tract infections (n = 8) and injury to the urinary system (n = 6) were the most common donor complications. Using the donor's internal iliac system, two arterial anastomoses were performed in all cases. Venous outflow was accomplished through the uterine veins (UVs) in 13 cases, a combination of the UVs and the ovarian/uteroovarian veins (OVs/UOVs) in 36 cases, and solely through the OVs/UOVs in 13 cases. Ischemia time was 161 and 258 minutes when using living donors (LD) and deceased donors (DD), respectively. Forty-eight uteri were successfully transplanted or fulfilled the purpose of transplantation, 41 from LDs and 7 from DDs. Twenty-five and four live childbirths from LDs and DDs have been reported, respectively.

CONCLUSION

 UTx is still experimental. Further series are required to recommend specific surgical techniques that best yield a successful transplant and reduce complications for donors and recipients.

Red Blood Cell Transfusion and its Relationship with Pedicle Thrombosis in Microvascular Free Flaps

BACKGROUND

 Free flaps have become a highly valuable tool for complex reconstructive surgeries. The requirement of red blood cell transfusion (RBCT) during the perioperative period is common and its effect on the free flap survival is debatable. The aim of this study was to determine the relationship between perioperative RBCT and vascular pedicle thrombosis (VPT).

METHODS

 For this study 302 free flaps performed between January 2006 and December 2019 were retrospectively analyzed. It included their characteristics from before, during, and after the surgical procedure. The incidence of VPT and flap survival were calculated based on Kaplan Meier's method and the relationship between VPT and perioperative variables were analyzed by Cox regression models.

RESULTS

 The transfusion group was represented by 62 flaps (20.5%) and no transfusion by 240 flaps. The overall transfusion requirement was 20.5% and the cumulative incidence of VPT was 9.11%. A statistically significant relationship was not demonstrated between flap survival and transfusion status (HR = 1.73 IC 95%: 0.5 to 3.96; p = 0.192) (p = 0.192) independently from the number of units transfused, the preoperative diagnosis of anemia, and the type of flap used and did not establish an increased risk of VPT.

CONCLUSIONS

 This study did not demonstrate an association between RBCT during preoperative period and the risk for VPT or microvascular free flap survival rate on postoperative follow up.

Case Volume-Dependent Changes in Operative Morbidity following Free Flap Breast Reconstruction: A 15-Year Single-Center Analysis

BACKGROUND

Operative morbidity is a common yet modifiable feature of complex surgical procedures. With increasing case volume, improvement in morbidity has been reported through designated procedural processes and greater repetition. Defined as a volume-outcome association, improvement in breast reconstruction morbidity with increasing free flap volume requires further characterization.

METHODS

A retrospective analysis was conducted among consecutive free flap patients using a two-microsurgeon model between January of 2002 and December of 2017. Patient demographics and operative characteristics were obtained from medical records. Complications including unplanned surgical intervention (take-back) and flap loss were obtained from prospectively kept databases. Individual surgeon operative volume was estimated by considering overall practice volume and correcting for the number of surgeons at any given time.

RESULTS

During the study period, 3949 patients met inclusion criteria. A total of 6607 breasts underwent reconstruction with 6675 free flaps. Mean patient age was 50 ± 9.4 years and mean body mass index was 28.8 ± 5.0 kg/m2. Bilateral reconstruction was performed on 2633 patients (66.5 percent), with 4626 breasts (70.5 percent) reconstructed in the immediate setting. Overall, breast and donor-site complications were reported in 507 breasts (7.7 percent) and 607 cases (15.4 percent), respectively. Take-back was required in 375 cases (9.5 percent), with complete flap loss occurring in 57 cases (0.9 percent). Based on annual flaps per surgeon, the incidence of complications decreased with increasing volume (slope = -0.12; p = 0.056).

CONCLUSION

Through procedural efficiency and execution of defined clinical processes using a two-microsurgeon model, increases in microsurgical breast reconstruction case volume result in decreased morbidity.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Not all flaps are created equal: Assessing the impact of active smoking in muscle-only versus perforator flaps for patients undergoing nonelective extremity-free tissue transfer-A case control study

INTRODUCTION

Active smoking is known to impair wound healing following free tissue transfer for reconstruction due to its vasoconstrictive effect on the microcirculation. The aim of this study was to evaluate the impact of flap selection on flap loss, in nonelective, traumatic extremity-free soft tissue transfer in active smokers.

METHODS

All patients undergoing a free tissue transfer for acute trauma of the extremity at a level I trauma center from 2011 to 2017 were identified. Breast reconstruction and osseous/osseocutaneous flaps were excluded. The study population was divided in two groups based on the type of flap used (muscle versus perforator flap). Factors known to be associated with impaired wound healing were extracted from the database. Primary outcome was major smoking related complications (complete/partial flap loss). Secondary outcomes included minor flap-related complications (infection, dehiscence) and donor site complications. The impact of smoking was assessed for the different type of flaps using multivariate analyses.

RESULTS

A total of 118 flaps were identified during the study period. Out of those, 52 were perforator-based fasciocutaneous flaps, while 66 were muscle flaps. Active smoking status resulted in a statistically significant increase in the incidence of major and minor complications in the perforator flap group (36% vs. 4%, adjusted odds ratio, AOR [95%CI]: 2.31[1.48,19.30], adj-p = 0.021 and 32% vs. 17%, AOR [95% CI]: 1.23[1.11,14.31], adj-p = 0.034) but had no impact in the muscle group.

CONCLUSIONS

The present study suggests a higher incidence of flap related complications in smokers when a perforator flap was selected but no impact when a muscle flap was utilized.

Impact of patients' gender on microvascular lower extremity reconstruction

The physiological differences between genders have significant implications for health and disease. With regard to microsurgery, results remain elusive as to whether male or female gender is an independent risk factor for free flap reconstruction. This study evaluated the impact of gender on outcomes of lower-extremity free-flap reconstructions. Within 7 years, 358 patients received 393 microvascular lower limb free flap reconstructions. The cases were divided into two groups according to patients' gender: male vs. female. Retrospective data analysis evaluated patients' demographics, perioperative details, surgical complications and flap outcomes over a 3-month follow-up period. Major and minor surgical complications, including total and partial flap loss, showed no significant differences between the investigated groups (p>.05). In addition, there was no significant difference with regard to the rate of surgical revision surgery, or the incidence of arterial and venous thrombosis (p>.05). Comparison of different flap types (fasciocutaneous ALT vs. gracilis muscle flaps) and type of anastomosis (end-to-end vs. end-to-side) also revealed no difference in outcomes in respect to gender. In conclusion, gender cannot be regarded as an independent risk factor for free flap reconstructions in patients with lower-extremity defects.

Sarcopenia is associated with blood transfusions in head and neck cancer free flap surgery

OBJECTIVE

To determine if sarcopenia is a predictor of blood transfusion requirements in head and neck cancer free flap reconstruction (HNCFFR).

METHODS

A single-institution, retrospective review was performed of HNCFFR patients with preoperative abdominal imaging from 2014 to 2019. Demographics, comorbidities (modified Charlson Comorbidity Index [mCCI]), skeletal muscle index (cm2/m2), oncologic history, intraoperative data, and 30-day postoperative complications (Clavien-Dindo score [CD]) were collected. Binary logistic regression was performed to determine predictors of transfusion.

RESULTS

Eighty (33.5%), 66 (27.6%), and 110 (46.0%) of n = 239 total patients received an intraoperative, postoperative, or any perioperative blood transfusion, respectively. Sixty-two (25.9%) patients had sarcopenia. Patients receiving intraoperative transfusions had older age (P = .035), more frequent alcoholism (P = .028) and sarcopenia (P < .001), greater mCCI (P < .001), lower preoperative hemoglobin (P < .001), reconstruction with flaps other than forearm (P = .003), and greater operative times (P = .001), intravenous fluids (P < .001), and estimated blood loss (EBL, P < .001). Postoperative transfusions were associated with major complications (CD ≥ 3; P < .001). Multivariate regression determined sarcopenia (P = .023), mCCI (P = .013), preoperative hemoglobin (P = .002), operative time (P = .036), and EBL (P < .001) as independent predictors of intraoperative transfusion requirements. Postoperative transfusions were predicted by preoperative hemoglobin (P = .007), osseous flap (P = .036), and CD ≥ 3 (P < .001). A perioperative transfusion was predicted by sarcopenia (P = .021), preoperative hemoglobin (P < .001), operative time (P = .008), and CD ≥ 3 (P = .018).

CONCLUSION

Sarcopenia is associated with increased blood transfusions in HNCFFR. Patients should be counseled preoperatively on the associated risks, and the increased blood product requirement should be accounted in resource-limited scenarios.

LEVEL OF EVIDENCE

4.

The Effect of Perioperative Blood Transfusions on Microvascular Anastomoses

Introduction: Perioperative transfusions are associated with complications of free flaps. The purpose of the present study was to find out whether there is a significant relationship between the risk of developing complications in vascular anastomoses and the history of transfusions. Methods: We studied 372 patients retrospectively with microsurgical reconstruction between 2009 and 2017 with regards to the number of red blood cell concentrates transfused. Complications were analyzed relative to flap loss and complications in microvascular anastomoses. Results: 130 patients (34.9%) received blood transfusions. Some 55% of them were transfused between the day of the intervention and the first postoperative day. Ninety-six patients were reoperated on (25.7%). Of those, thirty-six patients (37.5%) corresponded to anastomosis failure. The percentage of patients transfused among those who required reoperation was 55.2%. The percentage of patients transfused among those who were reoperated on within the first 72 h due to an alteration in the anastomosis was 60.6%, while it was 25.6% (Chi square P = 0.0001) for the rest of the patients. Conclusions: Although there is a strong association between transfusion and vascular anastomosis failure, it is not possible to establish the causation between the two.

Heme oxygenase‑1 improves the survival of ischemic skin flaps (Review)

Heat shock protein 32 (Hsp32), also known as heme oxygenase‑1 (HO‑1), is an enzyme that exists in microsomes. HO‑1 can be induced by a variety of stimuli, including heavy metals, heat shock, inflammatory stimuli, heme and its derivatives, stress, hypoxia, and biological hormones. HO‑1 is the rate‑limiting enzyme of heme catabolism, which splits heme into biliverdin, carbon monoxide (CO) and iron. The metabolites of HO‑1 have anti‑inflammatory and anti‑oxidant effects, and provide protection to the cardiovascular system and transplanted organs. This review summarizes the biological characteristics of HO‑1 and the functional significance of its products, and specifically elaborates on its protective effect on skin flaps. HO‑1 improves the survival rate of ischemic skin flaps through anti‑inflammatory, anti‑oxidant and vasodilatory effects of enzymatic reaction products. In particular, this review focuses on the role of carbon monoxide (CO), one of the primary metabolites of HO‑1, in flap survival and discusses the feasibility and existing challenges of HO‑1 in flap surgery.

A paintable phosphorescent bandage for postoperative tissue oxygen assessment in DIEP flap reconstruction

Flaps are common in plastic surgery to reconstruct large tissue defects in cases such as trauma or cancer. However, most tissue oximeters used for monitoring ischemia in postoperative flaps are bulky, wired devices, which hinder direct flap observation. Here, we present the results of a clinical trial using a previously untried paintable transparent phosphorescent bandage to assess the tissue's partial pressure of oxygen (pO₂). Statistical analysis revealed a strong relationship (P < 0.0001) between the rates of change of tissue oxygenation measured by the bandage and blood oxygen saturation (%stO₂) readings from a standard-of-care ViOptix near-infrared spectroscopy oximeter. In addition, the oxygen-sensing bandage showed no adverse effects, proved easy handling, and yielded bright images across all skin tones with a digital single-lens reflex (DSLR) camera. This demonstrates the feasibility of using phosphorescent materials to monitor flaps postoperatively and lays the groundwork for future exploration in other tissue oxygen sensing applications.

Clinical application for DSA combined with a double-chamber Fogarty catheter in the treatment of venous crisis

Introduction

Venous crisis, as a common vascular crisis post limb replantation, is usually treated with surgical exploration.

Aim

To investigate effects of digital subtraction angiography (DSA) combined with double-chamber Fogarty balloon catheter on venous crisis post replantation of limbs.

Material and methods

Twelve patients suffering from severed limbs were involved in this study. Patients underwent DSA combining double-chamber Fogarty balloon catheter operation. Colour Doppler ultrasound was used to diagnose patients with venous crisis. Patients were treated with rehydration, anti-infection, anticoagulation, and vasodilation. Indexes, including total joint active activity, working condition, remaining symptoms, appearance, feeling, and muscle strength, were evaluated.

Results

During operation, the limb was shortened to 0-1 cm in 8 cases, to 1-2 cm in 2 cases, and to 2-2.5 cm in 2 cases. According to DSA findings, popliteal vein thrombosis was formed at 0.6-4.2 cm and was removed from the popliteal vein. After removal of the thrombosis, DSA images showed re-canalization of the popliteal vein. A typical case of a 16-year-old patient underwent limb replantation; however, venous crisis was formed post operation. Postoperative colour Doppler ultrasound findings indicated re-canalization of the popliteal vein. Tibia and fibula were reduced and internally fixed, while the limb was survived post-operation. The degree of swelling of limbs was improved, and skin temperature was normal or 0.6-1.5°C lower than affected limbs. Skin colour was normal and activity was improved. Patients demonstrated sensory recovery grade of S³⁺ and two-point discrimination of 4.5 mm.

Conclusions

DSA combining double-chamber Fogarty balloon catheter, as a minimally invasive and fast approach, could accurately locate thrombi and improve pertinence of vein branches.

Combined (endo-)vascular intervention and microsurgical lower extremity free flap reconstruction-A propensity score matching analysis in 5386 ACS-NSQIP patients

BACKGROUND

Compromised lower limb perfusion due to vascular changes such as peripheral artery disease impedes wound healing and may lead to large-scale tissue defects and lower limb amputation. In such patients with defects and compromised or lacking recipient vessels, combined vascular reconstruction with free flap transfer is an option for lower extremity salvage.

METHODS

By using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2005-2018), we analyzed two patient cohorts undergoing (A) free flap lower limb reconstruction (LXTR) only and (B) combined (endo-)vascular reconstruction (vascLXTR). The preoperative variables assessed included demographic data and comorbidities, including smoking, diabetes mellitus, preoperative steroid use, and American Society of Anesthesiology (ASA) Physical Status Classification. Using a neighbor matching algorithm, we performed a 1:1 propensity score matching of 615 LXTR patients and 615 vascLXTR patients. Bivariate analysis for postoperative surgical and medical complications was performed for outcomes in the propensity-matched cohort.

RESULTS

We identified 5386 patients who underwent microsurgical free flap reconstruction of the lower extremity. A total of 632 patients underwent a combined (endo-)vascular intervention and lower extremity free flap reconstruction. Diabetes and smoking were more prevalent in this group, with 206 patients having diabetes (32.6%) and 311 being smokers (49.2%). More patients returned to the operating room in the cohort that underwent a combined vascular intervention (24.4% versus 9.9%; p<0.0001). The 30-day mortality for patients undergoing a combined vascular procedure was 3.5%, compared with 1.3% with free tissue transfer only (p<0.0001).

CONCLUSION

Despite the risks associated, the combined intervention decreases the very high mortality associated with limb amputation in severely sick patient populations. Careful preoperative assessment of modifiable risk factors may reduce complication rates while allowing limb salvage.

Correlation between Venous Thromboembolism Risk and Venous Congestion in Microvascular Reconstruction of the Lower Extremity

BACKGROUND

Risk for venous thromboembolism formation and the relationship to postoperative free flap venous congestion and flap failure have not been adequately evaluated in a trauma population. The authors aim to use the Caprini Risk Assessment Model to evaluate the association between venous thromboembolism risk and postoperative flap venous congestion following lower extremity free tissue transfer.

METHODS

A retrospective analysis was conducted of all patients who underwent lower extremity free flap reconstruction of traumatic defects at a single institution between 2007 and 2016. A Wilcoxon rank sum test was used for nonparametric analysis of aggregate Caprini Risk Assessment Model scores and flap outcomes. Flap venous congestion and failure rates as associated with the categorical variables underlying the Caprini Risk Assessment Model were further studied. Logistic regression was used to evaluate each of these outcomes and other flap-related covariates relative to the Caprini Risk Assessment Model categorical variables that had the greatest effect on our patient sample.

RESULTS

One hundred twelve patients underwent lower extremity free flap reconstruction. One hundred eight free flaps were analyzed. Eight patients were excluded. The majority of patients were male (75.9 percent) and required reconstruction because of acute trauma (68.1 percent versus 31.9 percent for chronic wounds). There was no statistically significant association found between age, body mass index, or timing of trauma versus venous congestion, flap failure, or other flap-related covariates.

CONCLUSION

In patients with significantly elevated Caprini Risk Assessment Model scores, there was no significant association between venous thromboembolism risk and flap failure following free tissue reconstruction of lower extremities.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Association between blood transfusions and complications in head and neck reconstruction: a systematic review and meta-analysis

PURPOSE

The aim of this meta-analysis is to assess the correlation between blood transfusions and the medical/surgical complications after head and neck reconstructive surgery.

METHODS

The PRISMA protocol was used and the literature search was performed on Pubmed, Scopus, Cochrane Library and Web of Science up to March 13, 2020. The risk of bias in individual studies was assessed through the Newcastle Ottawa Scale.

RESULTS

A total of 1219 records were screened after the electronic search, 22 of which were included in the qualitative analysis. Of there 22 scores, 18 articles were included in the meta-analysis. The OR for medical and surgical complications of transfused patients was 1,64 (95% CI 1.23-2.21); while, the OR for hospital readmission was 1.53 (95% CI 1.29-1.81).

CONCLUSIONS

The results of this meta-analysis suggested that blood transfusions are associated with both an increased risk of surgical and medical complications of head and neck flaps and with the hospital readmission.

Microsurgical reconstruction of extensive lower extremity defects with the conjoined parascapular and latissimus dorsi free flap

BACKGROUND

Extensive lower extremity soft-tissue defects pose a reconstructive challenge. We present our experience with the conjoined parascapular and latissimus dorsi (CPLD) free flap.

METHODS

From October 2008 to October 2017, 69 patients (14 female, 55 male) with a mean age of 50 years (range: 16-79 years) underwent reconstruction of lower extremity defects with the CPLD free flap. Mean defect size was 24 × 36 cm (range: 14 × 20 to 45 × 80 cm).

RESULTS

Mean latissimus dorsi (LD) flap size was 19 × 28 cm (range: 14 × 20 to 28 × 42 cm) and mean parascapular (PSC) flap size was 8 × 25 cm (range: 5 × 12 to 11 × 33 cm). Six patients (9%) experienced a total of eight microvascular complications: arterial thrombosis (n = 1), venous thrombosis (n = 6), combined arterial and venous thrombosis (n = 1). The re-exploration rate was 13%. Major complications of the donor-site were seen in 9 patients (13%), of the flap in 13 patients (19%), and of both in 6 patients (9%). Fifteen patients experienced partial flap necrosis (22%). Three CPLD and one PSC flap were lost (5%). PSC flap length was a significant predictor of distal flap necrosis (χ² (1) = 13.2, p = .004, OR = 1.343, 95% CI [1.098-1.642]). PSC flap width was a significant predictor of donor-site revisions (χ² (1) = 15.9, p = .010, OR = 4.745, 95% CI [1.584-14.213]). Arterio-venous loops (AVLs) tended to increase the risk of microvascular thrombosis (χ² (1) = 3.7, p = .08, OR = 4.1, 95% CI [0.9-18.7]).

CONCLUSIONS

The CPLD free flap is an extremely large and highly reliable flap, allowing one-stage reconstruction of extensive lower extremity defects. It may overcome the need for multiple flaps in selected cases.

Etiology and Survival of Secondary Revascularizations after Hand and Digit Replantations

Introduction  Hand and digit replantations can be complicated by vascular insufficiency necessitating revision of the original replantation. To date, few studies have evaluated outcomes in secondary revascularizations following replantation. Therefore, the objective of this study was to evaluate the incidence, etiology, and survival rates following secondary revascularization after hand and digit replantations. Materials and Methods  A literature search was performed on NCBI for studies documenting secondary revascularization procedures following hand and digit replant. Studies were evaluated for the etiology of vascular failure, frequency of secondary revascularization, and survival rates following intervention. Statistical analysis was conducted across the pooled dataset. Results  A total of 16 studies including 1,192 amputations were analyzed. We found that 16.9% (201/1,192) of replants were complicated by vascular compromise. The frequency of vascular compromise was not statistically different between arterial and venous etiologies. The survival rate following secondary revascularization was 55.6%, with no significant difference between the arterial and venous groups. Secondary arterial revascularization was often treated with arterial revision (nine of nine studies) and/or with vein grafting (two of nine studies). Secondary revascularization for venous insufficiency resulted in different survival rates for nonsurgical modalities (58%) versus vein revision (37.5%) versus vein grafting (100%). Conclusion  Survival rates following secondary revascularization are lower; however, they may be improved using vein grafts following venous insufficiency. These data can be used to better understand the etiology of replant failure and guide decision-making.

Impact of Smoking Status in Free Deep Inferior Epigastric Artery Perforator Flap Breast Reconstruction: A Multicenter Study

BACKGROUND

 Several patient-related factors have been identified with regard to the safety and efficacy of breast reconstructions. Using the largest database available in Europe, the presented study investigated the impact of cigarette smoking on deep inferior epigastric artery perforator (DIEP) free-flap breast reconstructions.

METHODS

 In total, 3,926 female patients underwent 4,577 free DIEP-flap breast reconstructions after malignancies in 22 different German breast cancer centers. The cases were divided into two groups: nonsmokers (NS) and smokers (S). Impact of smoking on surgical complications, controlled for covariates, and cluster effects within the cancer centers were analyzed by using generalized linear mixed models.

RESULTS

 Overall, there was no significant difference between the groups of patients regarding the rate of total flap loss. However, the rate of partial flap loss (0.9 vs. 3.2%, p < 0.001) and wound-healing disturbances requiring revision surgery (donor site: 1.5 vs. 4.0; recipient site: 1.3 vs. 3.6%, both p < 0.001) was significantly higher in smokers. Multivariable analysis identified smoking to be an independent risk factor for revision surgery (p = 0.001) and partial flap loss (p < 0.0001).

CONCLUSION

 Our findings suggest that successful free tissue transfer can be achieved in smokers despite higher rates of partial flap losses and wound-healing disturbances. However, patients with a history of smoking requiring DIEP flap reconstruction should be critically evaluated preoperatively, informed in detail about the higher risk of complications and encouraged to quit smoking prior to surgery.

Analysis of Selection of Recipient Vein, Number of Outflows, Style and Technique in Head and Neck Venous Anastomosis and a Proposed Algorithm

Surgeons have preferential ways of performing venous anastomosis in head and neck microsurgery. However, controversies exist regarding the superiority of each method. This study aims to determine the effects of these variables on the rates of thrombosis and flap failure, and propose an algorithm to be used as a facilitator in the decision-making process. A total of 208 microsurgical reconstructions on 199 patients from a single surgeon's data were evaluated. Selection of recipient vein (superficial vs. deep), style of anastomosis (end-to-end vs. end-to-side), number of outflows (one vs. two) and technique of anastomosis (hand-sewn vs. coupler) were compared. Selection was done according to the pre- and intraoperative plan, as well as, surgeon's clinical judgement. Outcomes were determined as rates of venous thrombosis and flap failure. Five patients (2.4%) had venous problems, leading to two partial and three total flap failures. Selection of the recipient vein, style and number of outflows did not affect the outcomes, whereas coupler use decreased the rates of venous thrombosis and flap failure (p=0.008). Although it is difficult to set dogmatic criteria to achieve consistent outcomes, coupler use in this study prevented flap failure. An algorithmic approach was proposed with the results of the data and literature to increase the success in microsurgical anastomosis. Surgeons should use algorithms and sound judgement with adherence to microsurgical principles to obtain the best results for each patient.

Thromboelastometry for Assessing Risks of Free Flap Thrombosis in Patients Undergoing Microvascular Surgery

Introduction: Coagulation assessment is often missing in microvascular surgery. We aimed at evaluating the predictive value of thromboelastometry for free flap thrombosis in microvascular surgery patients. Materials and Methods: We enrolled 103 adult patients with traumatic injuries scheduled for microvascular free flap surgery into a prospective observational study. Thirty-six patients with recent trauma underwent surgery within 30 days (ES group), and were compared with 67 trauma patients who underwent surgery later than 30 days (late surgery, LS group) after the injury. Rotational thromboelastometry (RTE) was performed before surgery. Functional fibrinogen to platelet ratio (FPR) ≥ 42 was selected as the main hypercoagulability index. Free flap thrombosis was set as primary outcome. Thrombotic risk factors and duration of surgery related to free flap thrombosis were secondary outcomes. Statistical significance p < 0.05; not significant NS. Results: Six patients (16.7%) in the ES group and 10 (14.9%) in the LS group had free flap thrombosis (NS). In the entire cohort, free flap thrombosis rate increased in the presence of thrombogenic comorbidities (OR 4.059, CI 1.33-12.37; p = 0.014) and prolonged surgery times (OR 1.007, CI 1 - 1.012; p = 0.05). Although hypercoagulability occurred more frequently in the ES group (44.4%) than in the LS group (11.9%; p < 0.001), it was not associated with higher free flap thrombosis rate. In ES group patients with surgery times > 240 min, the risk of free flap thrombosis increased (OR 3.5, CI 1.16-10.6; p = 0.026) with 93.3% sensitivity and 86.7% specificity (AUC 0.85; p = 0.007). In contrast, in LS patients hypercoagulability increased the odds of free flap thrombosis (OR 8.83, CI 1.74-44.76; p = 0.009). Moreover, a positive correlation was found between FPR ≥ 42 and free flap thrombosis rate (r = 0.362; p = 0.003). In the LS group, the presence of thrombogenic comorbidities correlated with free flap thrombosis rate (OR 7, CI 1.591-30.8; p = 0.01). Conclusions: In LS patients with thrombogenic comorbidities, thromboelastometry supports the detection of hypercoagulability and predicts free flap thrombosis risk. In ES patients, postoperative hypercoagulability did not predict free flap thrombosis. Prolonged surgery time should be considered as a risk factor.

Prognostic Nutritional Index is a Predictor of Free Flap Failure in Extremity Reconstruction

The nutritional condition of patients is an important prognostic factor in various diseases. Free flap failure is a serious complication in patients undergoing free flap reconstruction, increasing morbidity and hospital costs. We evaluated the predictive factors, including the prognostic nutritional index (PNI), associated with free flap failure in extremity reconstruction. The PNI was calculated as follows: 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (per mm³), with a PNI <40 defined as low. Univariate and multivariate logistic regression analyses were performed to evaluate factors predictive of free flap failure. Postoperative outcomes, including duration of hospital stay and rate and duration of intensive care unit admission, were also evaluated. Of the 625 patients included, 38 (6.1%) experienced free flap failure. Multivariate logistic regression analysis revealed that predictors of free flap failure were female (odds ratio: 2.094; p = 0.031) and a low PNI (odds ratio: 3.859; p <0.001). The duration of hospital stay was significantly longer in patients who did than those who did not experience free flap failure (62.1 ± 55.5 days vs. 28.3 ± 24.4 days, p <0.001). A low PNI is associated with free flap failure, leading to prolonged hospital stay. This result suggests that the PNI can be simply and effectively used to predict free flap failure.