The Utility of Preoperative Venous Testing for Lower Extremity Flap Planning in Patients with Lower Extremity Wounds:

Optimizing Lower Extremity Local Flap Reconstruction in Peripheral Vascular Disease

BACKGROUND

Local flaps remain a valuable reconstructive tool as a means for limb salvage for patients with advanced arterial disease. Our single-center, retrospective cohort study aims to compare the outcomes of different patterns of blood flow affected by vascular disease to pedicles in local flap reconstruction of the foot and ankle.

METHODS

A retrospective review of 92 patients and 103 flaps was performed. On angiograms, pattern of blood flow to the flap pedicle was determined to be direct inline flow (DF) or indirect flow (IF). Patterns of IF were either by arterial-arterial connections (AC) or unnamed randomized collaterals (RC). Primary outcomes were immediate flap success and limb salvage. Comparative analyses were performed using the χ2 and Fisher tests for categorical variables.

RESULTS

Among all flaps, 73.8% (n = 76/103) had DF and 26.2% (n = 27/103) had IF. Both groups experienced similar rates of immediate flap success (DF = 97.3% vs IF = 92.6%, P = 0.281) and limb salvage (DF = 75.% vs IF = 66.7%, P = 0.403). However, the rate of contralateral amputation was significantly higher in the IF group (26.9% vs 5.3%, P = 0.006). When comparing the 3 distinct patterns of blood flow (DF vs AC vs RC), pedicled flaps were more commonly supplied by DF and AC, while random pattern flaps were more commonly supplied by RC (P = 0.042).

CONCLUSIONS

Alternative routes of revascularization can maintain local flap viability and achieve similar rates of limb salvage but risks contralateral amputation. We found that pedicled and local muscle flaps require inline blood flow or blood supply by ACs. Meanwhile, random pattern flap can be supported by random collaterals.

Extreme Limb Salvage: The Thin SCIP Flap for Distal Amputation Coverage in Highly Comorbid Patients

BACKGROUND

Limb length preservation is correlated with overall survival. Successful free flap coverage of forefoot, midfoot, and hindfoot amputations can prevent more proximal below-knee amputations but is challenging in patients with multiple comorbidities. The thin superficial circumflex iliac artery perforator (SCIP) flap is well-suited for these patients, as it provides thin, pliable tissue from a favorable donor site.

METHODS

A retrospective review of all patients with distal amputations requiring coverage with a thin SCIP flap between 2016 to 2022 was performed. Patient demographics, amputation levels, and wound characteristics in addition to flap and microsurgery details were analyzed. The primary outcome was limb salvage. Secondary outcomes included partial flap necrosis, flap revision rate, and additional postoperative complications.

RESULTS

Thirty-two patients (mean age, 57.3 years) underwent reconstruction of forefoot, midfoot, and hindfoot amputations with thin SCIP flaps (mean follow-up, 36 months). Twenty-eight patients (87.5%) had diabetes, 27 (84.4%) had peripheral artery disease, and 15 (46.9%) were dialysis-dependent. Average flap size was 59.5 cm 2 and average flap thickness was 5.7 mm. Successful limb salvage was achieved in 27 patients (84.3%). Three cases (9.4%) had total flap loss. Twenty-one flaps (65.6%) had partial necrosis, of which 12 (57.1%) healed with conservative management and 7 (33.3 %) healed after late revision.

CONCLUSIONS

The thin SCIP flap is a useful option for coverage of distal pedal amputations in patients with significant comorbidities. Despite higher rates of partial flap necrosis, free flap reconstruction allowed for high rates of limb salvage in a challenging patient population.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Implications of Single-Vessel Runoff on Long-Term Outcomes of Free Tissue Transfer for Lower Extremity Reconstruction

BACKGROUND

 Patients with complex lower extremity (LE) wounds and single-vessel LE runoff (1-VRO) are often considered for amputation. While more challenging, free tissue transfer (FTT) is a means for limb salvage. This study aims to demonstrate the feasibility of limb salvage with FTT in patients with 1-VRO.

METHODS

 Patients undergoing FTT by a single surgeon between 2011 and 2021 were retrospectively reviewed. Data collected included demographics, wound characteristics, vascular status, and operative details. Patients were divided into cohorts based on 1- versus 3-VRO of tibial vessel inflow. Outcomes of interest included postoperative complications such as flap necrosis, flap success, limb salvage, and ambulatory status.

RESULTS

 A total of 188 patients underwent FTT to LE, with 25 patients (13.3%) having 1-VRO. Patients with 1-VRO had a comparable prevalence of diabetes (56.0% vs. 50.0%, p = 0.569) and end-stage renal disease (8.0% vs. 3.7%, p = 0.319). Osteomyelitis was more common in the 1-VRO group (80.0% vs. 60.1%, p = 0.056). FTT donor sites and flap composition were similar between cohorts. At mean follow-up of 21.2 months (interquartile range 24.5:5.6, 30.1 months), limb salvage rates were similar between cohorts (84.0% vs. 91.4%, p = 0.241), with no significant differences in ambulatory status or mortality. Higher complication rates occurred in the 1-VRO cohort (48.0% vs. 21.5%, p = 0.004), of which partial flap necrosis was more prevalent in the 1-VRO group (8.0% vs. 1.2%, p = 0.029). There was no difference in flap success rates between groups (p = 0.805). More postflap angiograms were performed in the 1-VRO group (32.0% vs. 9.2%, p = 0.001), but there was no difference in need for repeat percutaneous endovascular intervention between groups.

CONCLUSION

 This study demonstrates that FTT reconstruction to the LE remains a reliable reconstruction option for limb salvage in patients with single-vessel supply to the LE. Reliance on advanced perioperative management and patient optimization is effective at reducing negative outcomes.

Thrombophilia and Preoperative Deep Venous Thrombosis and Their Effect on Free Flap Survival: A Scoping Review

Background: A proper preoperative planning is essential to prevent flap failure. However, venous workup for flaps has not been commonly performed or utilized as a preoperative screening tool. A scoping review was conducted to explore preoperative venous system screening, including deep vein thrombosis diagnosis, and its effect on flap survival rate. This review identified existing gaps of knowledge and emphasized potential research areas for future studies. Methods: Two independent reviewers searched 3 electronic databases from inception to September 2020. Retrieved appropriate articles were selected systematically by title, abstract, and full review of the article. Studies were included if they enrolled patients who had thrombophilia or deep venous thrombosis (DVT) preoperatively and had undergone a free flap reconstruction. For eligible studies, the following information was extracted: basic demographics (sex, age, comorbidities), preoperative scans type, free flap type, clotting mode (causes), wound type, and flap survival. Results: Seventeen articles were found eligible for this review. Traumatic aetiology was found in 63 (33.6%) patients, while 124 (66.3%) patients had a non-traumatic aetiology. Preoperative screening for patients with non-traumatic aetiology was reported in 119 patients. In these patients, the flap survived in 107 (89.91%) patients. Four studies investigating patients with traumatic DVT aetiology, 60 patients (out of 63) had a preoperative computed tomography angiography or duplex. Those patients had 100% flap survival rates. Conclusion: Further investigations are required to identify venous thrombosis incidence in patients with non-traumatic thrombosis aetiology as this cohort of patients is at high risk of flap failure. Finally, the prognostic validity of available preoperative screening tools to identify high-risk patients should be assessed, such as imaging techniques, which would include venous duplex scanning, may prevent failure in free flap surgery.

The impact of pre-existing venous pathology on lower limb free flap reconstruction and the role of preoperative screening: a systematic review

Lower limb reconstruction is performed to replace like with like and achieve tissue durability. Free flaps are a method of reconstruction commonly used to manage cases of lower limb deficits. However, the failure rate is 8.5%, with venous thrombosis and congestion playing a significant role. Despite this, preoperative venous mapping of recipient site before free flap reconstruction is not routinely practiced, often resulting in pathologies remaining unidentified until the intraoperative stage. The aim of the review was to evaluate the existing literature on the topic of lower limb preoperative venous assessment, screening, and its effect on lower limb free flap survival. Five different databases were searched from their inception to August 2021. The search terms and included studies were independently reviewed by two investigators for their eligibility. Eleven articles were eligible for inclusion, with a combined patient population of 99, and 107 flaps were identified to have lower limb pathology at the donor or recipient vein. Venous pathology was detected preoperatively in 69 veins using ultrasound duplex scanning and computed tomography angiography; of them, 3 (4.34%) resulted in failure. In comparison, 38 veins were diagnosed with venous pathology intraoperatively; of them, 5 (13.85%) failed. The studies evaluated in this review demonstrated that preoperative screening for venous pathology showed a higher flap survival rate. It can therefore be inferred that developing a standardized preoperative process for identifying venous issues in lower limb free flap reconstruction may improve outcomes. This can be explored in future research, with a focus on assessing the validity and efficacy of such screening tools, and their role in the management of patients identified with venous pathology.

Selection of deep or superficial recipient vein in lower extremity reconstruction using free flap: A systematic review and meta-analysis

BACKGROUND

Free flap surgeries are useful procedures for lower-extremity reconstruction. Recipient vein selection for anastomosis is important to avoid venous congestion and thrombosis. Although deep or superficial venous system can be used as a recipient vein site, there is a lack of consensus on which system would be superior to avoid postoperative complications. This systematic review and meta-analysis aimed to assess the differences in outcomes between deep and superficial vein anastomosis for lower-extremity free flap reconstruction.

METHODS

The PubMed, Scopus, Web of Science, and Cochrane Library medical databases were systematically searched from inception to April 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. A comparative meta-analysis was conducted on studies of deep and superficial venous system anastomosis outcomes, comprising vascular thrombosis, reoperation, complete flap necrosis, and any flap necrosis. The fixed-effects meta-analysis model was used when low heterogeneity (I²  < 50%) was present.

RESULTS

Six studies with 789 flaps were included in the analysis and qualitative and quantitative syntheses. The rate of vascular thrombosis (8.2% vs. 15.1%; p = .005) was significantly lower for flaps involving deep vein anastomosis than for those involving superficial vein anastomosis. The rate of reoperation after deep vein anastomosis was lower than that after superficial vein anastomosis, with no statistically significant difference (9.0% vs. 14.7%; p = .06). There were no significant differences in the rates of complete (2.5% vs. 2.0%; p = .90) or any flap necrosis (7.0% vs. 9.8%; p = .20).

CONCLUSION

Deep vein anastomosis might be recommended for avoiding vascular thrombosis.

Expanding Criteria for Limb Salvage in Comorbid Patients with Nonhealing Wounds: The MedStar Georgetown Protocol and Lessons Learned after 200 Lower Extremity Free Flaps

BACKGROUND

Lower extremity salvage in the setting of nonhealing wounds requires a multidisciplinary approach for successful free tissue transfer. Patients with comorbidities including diabetes mellitus and peripheral vascular disease were previously considered poor candidates for free tissue transfer. However, amputation leads to functional decline and severely increased mortality. The authors present their institutional perioperative protocol in the context of 200 free tissue transfers performed for lower extremity salvage in a highly comorbid population.

METHODS

The authors reviewed an institutional database of 200 lower extremity free tissue transfers performed from 2011 to 2019. Demographics, comorbidities, wound cause and location, intraoperative details, flap outcomes, and complications were compared between the first and second 100 flaps. The authors document the evolution of their institutional protocol for lower extremity free tissue transfers, including standard preoperative hypercoagulability testing, angiography, and venous ultrasound.

RESULTS

The median Charlson Comorbidity Index was 3, with diabetes mellitus and peripheral vascular disease found in 48 percent and 22 percent of patients, respectively. Thirty-nine percent of patients tested positive for more than three hypercoagulable genetic conditions. The second group of 100 free tissue transfers had a higher proportion of patients with decreased vessel runoff (35 percent versus 47 percent; p < 0.05), rate of endovascular intervention (7.1 percent versus 23 percent; p < 0.05), and rate of venous reflux (19 percent versus 64 percent; p < 0.001). Flap success (91 percent versus 98 percent; p < 0.05) and operative time (500 minutes versus 374 minutes; p < 0.001) improved in the second cohort.

CONCLUSIONS

Standardized evidence-based protocols and a multidisciplinary approach enable successful limb salvage. Although there is a learning curve, high levels of salvage can be attained in highly comorbid patients with improved institutional knowledge and capabilities.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

A retrospective evaluation of 182 free flaps in extremity reconstruction and review of the literature

Introduction: During the past decades, free flaps have been given a central role in the reconstructive surgery. Especially in the extremities, where there is a scarcity of available tissues for local flaps, free flaps play a central part. The aim of this study was to evaluate the risk factors contributing to partial and total flap failure. Patients and methods: In a retrospective cohort study, all data concerning patients who underwent free flap reconstruction of the extremities during the first five years since the founding of the department of plastic surgery were gathered. Patient- and surgery-related risk factors were analyzed in correlation to the postoperative complications. Results: In total, 182 free flaps were included in this study. Partial and total flap failure were noted in 21.42% and 17.03%, respectively. A correlation was seen between the time lapsed from debridement until flap coverage, with flaps performed between day 4 and 14 having the least quote of flap failure (p=0.022). Gender, age, arterial hypertension, nicotine abuse, diabetes mellitus, peripheral arterial disease and the number of anastomosed veins were not significantly associated with free flap failure. Conclusion: Our study showed that free flaps can be safely performed in healthy patients as well as in patients with risk factors, with an acceptable flap loss rate. Randomized controlled studies are needed to clarify the exact role of each risk factor in free flap surgery.

Analysis of Anastomotic Venous Factors in Traumatic Lower Extremity Injuries Reconstructed by Free Flap

Background

Venous thrombosis has been shown to be the most frequent cause of free flap failure in traumatic lower extremity injuries. However, the roles of various anastomotic venous factors, including venous anastomosis (end-to-end (ETE) or end-to-side (ETS)), venous outflow (one vein or two veins), and recipient venous selection (deep or superficial vein), remain unclear. This retrospective study aims to investigate factors contributing to microvascular complications in patients with lower extremity Gustilo type IIIB/IIIC injuries reconstructed by free flap with a focus on the three abovementioned venous factors.

Methods

A total of 44 flap treatment outcomes of 41 patients with these injuries from 2015 to 2020 were assessed according to the three venous factors (type of anastomosis, venous outflow, and vein selection).

Results

The average patient age was 52 years, with the majority (75.6%) being male. Eight patients (18.2%) returned to the operating room due to venous thrombosis, and five patients (11.4%) experienced total flap failure. The following factors were suspected to have contributed to venous thrombosis: vein size mismatch (n = 2) and recipient vein insufficiency possibly due to post-traumatic vessel disease (PTVD) (n = 6). End-to-side (ETS) anastomoses showed lower venous thrombosis rates than end-to-end (ETE) anastomoses (6.3% versus 25%, p = 0.22), two-vein outflows had lower rates than one (8.3% versus 30%, p = 0.07), and deep veins had the lowest thrombosis rates (7.7%), whereas superficial veins had the highest (38.5%).

Conclusion

The key venous factors in preventing venous thrombosis include using as many two-vein ETS anastomoses as possible to deep recipient veins.

The Need to Improve Patient-Centered Outcome Reporting Following Lower Extremity Flap Reconstruction: A Systematic Review and Meta-analysis

INTRODUCTION

 Research in lower extremity (LE) wound management involving flap reconstruction has primarily focused on surgeon-driven metrics. There has been a paucity in research that evaluates patient-centered outcomes (PCO). This systematic review and meta-analysis examines articles published between 2012 and 2020 to assess whether reporting of functional and quality of life (QOL) outcomes have increased in frequency and cohesiveness, compared with the previous two decades.

METHODS

 PubMed and Ovid were queried with appropriate Medical Subject Heading (MeSH) terms for studies published between June 2012 and July 2020. For inclusion, each study had to report any outcome of any tissue transfer procedure to the LE in comorbid patients, including complication rates, ambulation rates, flap success rates, and/or QOL measures. The PCO reporting prevalence was compared with a previous systematic review by Economides et al which analyzed papers published between 1990 and June 2012, using a Pearson's Chi-squared test.

RESULTS

 The literature search yielded 40 articles for inclusion. The proportion of studies reporting PCO was greater for literature published between 1990 and 2012 compared with literature published between 2012 and 2020 (86.0 vs. 50.0%, p < 0.001). Functional outcomes were more commonly reported between 1990 and 2012 (78.0 vs. 47.5%, p = 0.003); similarly, ambulatory status was reported more often in the previous review (70.0 vs. 40.0%, p = 0.004). This study solely examined the rate at which PCO were reported in the literature; the individual importance and effect on medical outcomes of each PCO was not evaluated.

CONCLUSION

 Less than 50% of the literature report functional outcomes in comorbid patients undergoing LE flap reconstruction. Surprisingly, PCO reporting has seen a downward trend in the past 8 years relative to the preceding two decades. Standardized inclusion of PCO in research regarding this patient population should be established, especially as health care and governmental priorities shift toward patient-centered care.

Free Tissue Transfer for Patients with Chronic Lower Extremity Wounds

Chronic lower extremity wounds are defined as wounds that fail to heal within 3 months of defect onset. Free tissue transfer offers an opportunity for limb salvage and length preservation. Preoperative optimization includes a medical and nutritional consult, complete work-up by vascular surgery, and an analysis of bony stability and gait biomechanics by podiatric surgery. In the authors' practice, the thigh has proved the workhorse donor site and offers fasciocutaneous and muscle-based flaps depending on defect characteristics. Postoperative care requires early monitoring for flap compromise and continued long-term follow-up for wound recurrence.

Intraoperative Utility of the Implantable Doppler in Lower Extremity Reconstruction: A Matched Case-control Study

Background:

Patients with diabetes mellitus and peripheral vascular disease have high rates of thrombogenic vessels. The implantable (Cook) Doppler in lower extremity reconstruction can optimize microsurgical outcomes in this population.

Methods:

Patients undergoing lower extremity free flap reconstruction who did not have an implantable Doppler probe placed were matched with patients who received an implantable Doppler probe. Groups were matched based on wound location, history of peripheral vascular disease, number of vessel runoffs, and number of venous anastomoses and postoperative outcomes compared.

Results:

Thirty patients were included: 15 in the control group and 15 in the implantable Doppler group. Mean age was 60.2 ±10.2 years, and mean BMI was 28.7 ± 5.0 kg/m². There was a high prevalence of diabetes mellitus (13; 43.3%) and peripheral vascular disease (4; 13.3%). Takebacks due to vascular compromise were significantly higher in the control than in the implantable Doppler group (26.7% versus 0.0%, P = 0.032). Among flaps that required takeback to the operating room, the majority were muscle-based without a skin paddle (75.0%). Vascular compromise was due to arterial insufficiency in 2 cases and venous thrombosis in 1 case. The salvage rate among the takebacks of the non-implantable Doppler group was 0.0%, resulting in a 26.7% flap failure rate in the non-implantable Doppler group when compared with 0.0% flap loss in the implantable Doppler group (P = 0.032).

Conclusion:

The implantable Doppler probe optimizes flap inset intraoperatively in lower extremity free flap reconstruction and can significantly decrease takebacks due to vascular complications, thereby increasing flap success.

Early Results of Supporting Free Flap Coverage of Mangled Lower Extremities with Long Saphenous Arteriovenous Loop Grafts

BACKGROUND

The ability to salvage the mangled lower extremity is both technically challenging and time consuming. It requires the collaborative efforts among multiple surgical specialties in addition to comprehensive post-traumatic wound follow-up. Our institution has integrated a dynamic effort among these specialists in the planning and facilitating a successful limb salvage program with creation of a mangled extremity algorithm. An integral part in this process is the vascular inflow to prepare coverage for large tissue defects lacking adequate recipient targets. Utilization of long saphenous arteriovenous (AV) loop has been cited with minimal data available using larger inflow vessels in the acute trauma setting. We performed a retrospective review and describe our early experience using our protocol with AV loop creation with free flap reconstruction to salvage traumatic leg injuries. Using the data, we sought to develop a mangled extremity protocol for trauma centers to guide mangled limb salvage.

METHODS

Since June 2016, 398 patients were admitted to our level II trauma facility with isolated traumatic wounds to the lower extremities. Thirty-one limbs were deemed mangled in which 21 received primary amputations due to multiple factors. Ten patients admitted from the trauma service with isolated mangled lower extremities injuries were identified for review. All 10 patients sustained severe crush injuries with large soft tissue defects and decreased perfusion for healing but deemed salvageable by multispecialty assessment. Mangled extremity severity scores were tabulated. Patients age ranged from 21-44 years, with 8 men and 2 women. Repeated debridements until successful sterilization of the wounds were accomplished. Ten long saphenous vein AV loops were anastomosed to the at or above knee popliteal vessels for free flap reconstruction. All patients were followed post-AV loop creation for vascular complications and wound assessments.

RESULTS

All 10 patients had sterilization of the wounds with repair of the fracture site before vascular reconstruction. Mean debridement to surgical site sterilization was 4.3 washouts (range 2-7). Successful AV loop creation with long saphenous vein was completed in 100% of patients without vascular complications nor steal events. Free flap tissue transfers directly connected to the loop were completed using 6 rectus abdominis, 3 latissimus dorsi, and 1 anterior thigh graft within 10 days of its creation. Patency rates of the AV loop was 100% with 10 successful flap transfers and 90% amputation free survival. One flap did not survive due to recurrent bacterial infection of the hardware. The 9 patients with successful procedures reached preoperative ambulatory status within 3 months after their final surgery. At 24 months follow-up, 90% amputation free survival is still maintained.

CONCLUSIONS

Although a small patient cohort, utilization of long saphenous vein AV loop is successful as a bridge to free flap transfer for isolated mangled lower extremities. Development and incorporation of our mangled extremity protocol to guide limb salvage has proven successful in our early experience. Long-term data need to be complied to assess patency of the free flap transfer and quality of life outcomes.