Vascular considerations in foot and ankle free tissue transfer: Analysis of 231 free flaps

Evaluation of modified frailty index for predicting post-operative outcomes after lower-extremity free-flap reconstruction

BACKGROUND

Risk stratification for complex procedures such as microsurgical reconstruction of the lower extremities is an important part of preoperative planning and counseling. The aim of this study was to determine the effectiveness of the modified five-item frailty index (5-mFI) score, a validated tool for assessing risk in surgical patients, in predicting postoperative complications after lower extremity (LE) free flap reconstruction.

METHODS

A retrospective review of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was conducted from 2010 to 2020 on patients who underwent LE free-flap reconstruction. 5-mFI scores were calculated and patients were categorized as 5-mFI ≥2 or <2. The primary endpoint was the presence of 30-day overall complications. The secondary endpoints included 30-day readmission, need for reoperation, and need to discharge to a care facility. Comparisons were made using one-way analysis of variances, Pearson's chi-squared test, or Fisher's extract test. Multivariable logistic regression models were performed for sex, age, BMI, smoker status, operative time, and ASA classification.

RESULTS

Total of 294 (61.6% males) patients were identified. Univariate analysis showed 5-mFI ≥2 had higher rates of overall complications (p = .043) and hematologic complications (p = .033). In this population, there were also higher rates of reoperation (p = .003) and discharge to care facility (p < .001). Multivariable regression models further substantiated that 5-mFI ≥2 was independently associated with increased overall complications [2.46, CI: 1.10-5.59, p = .031], hematologic complications [2.55, 1.02-6.35, p = .046], reoperation [4.55, 1.54-13.3, p = .006], and discharge to facility [2.86, 1.27-6.45, p = .011].

CONCLUSIONS

There is a strong association of 5-mFI ≥2 with adverse post-operative outcomes in male patients undergoing LE free-flap reconstruction. This can be a valuable adjunct in the counsel of patients for whom lower extremity salvage is feasible.

Risk assessment in delayed free flap reconstruction for severe lower extremity trauma

PURPOSE

This study aims to identify serum biomarkers that contribute to vascular thrombosis and complete flap failure in delayed reconstruction with free flaps, as well as to develop a scoring system of risk assessment including these biomarkers.

METHODS

A retrospective review of the database was conducted for lower extremity open fractures reconstructed between 7 and 90 days from injury, from March 2014 to February 2022. We investigated changes in platelet count (PLT), D-dimer, creatine phosphokinase (CPK), and C-reactive protein (CRP) and then, developed a risk assessment system including these biomarkers as risk factors.

RESULTS

A total of 62 free flaps were enrolled, and vascular thrombosis occurred in 14 flaps (22.6%), 9 of which (14.5%) developed complete flap failure. The risk assessment score was set to a maximum of 6 points for 6 items: age ≤ 40 years, time from injury to coverage ≥ 14 days, zone of injury from middle to distal leg, D-dimer on the day of injury ≥ 60 µg/mL, maximum value of CPK ≥ 10,000 U/L, and maximum value of CRP ≥ 25 mg/dL. The best cutoff score was 3 in the vascular thrombosis model (sensitivity: 0.79, specificity: 0.77) and 4 in the complete flap failure model (sensitivity: 0.78, specificity: 0.92).

CONCLUSIONS

Our risk assessment system showed that the risk of vascular thrombosis was high at ≥ 3 points and that of complete flap failure was high at ≥ 4 points. Significantly, elevated levels of D-dimer, CPK, and CRP require more caution during reconstruction using free flaps.

Assessment of Risk Factors Correlated with Outcomes of Traumatic Lower Extremity Soft Tissue Reconstruction

Identifying risk factors for traumatic lower extremity reconstruction outcomes has been limited by sample size. We evaluated patient and procedural characteristics associated with reconstruction outcomes using data from almost four million patients.

Methods

The National Trauma Data Bank (2015-2018) was queried for lower extremity reconstructions. Univariable and multivariable analyses determined associations with inpatient outcomes.

Results

There were 4675 patients with lower extremity reconstructions: local flaps (77%), free flaps (19.2%), or both (3.8%). Flaps were most commonly local fasciocutaneous (55.1%). Major injuries in reconstructed extremities were fractures (56.2%), vascular injuries (11.8%), and mangled limbs (2.9%). Ipsilateral procedures prereconstruction included vascular interventions (6%), amputations (5.6%), and fasciotomies (4.3%). Postoperative surgical site infection and amputation occurred in 2% and 2.6%, respectively. Among survivors (99%), mean total length of stay (LOS) was 23.2 ± 21.1 days and 46.8% were discharged to rehab. On multivariable analysis, vascular interventions prereconstruction were associated with increased infection [odds ratio (OR) 1.99, 95% confidence interval (CI) 1.05-3.79, P = 0.04], amputation (OR 4.38, 95% CI 2.56-7.47, P < 0.001), prolonged LOS (OR 1.59, 95% CI 1.14-2.22, P = 0.01), and discharge to rehab (OR 1.49, 95% CI 1.07-2.07, P = 0.02). Free flaps were associated with prolonged LOS (OR 2.08, 95% CI 1.74-2.49, P < 0.001).

Conclusions

Prereconstruction vascular interventions were associated with higher incidences of adverse outcomes. Free flaps correlated with longer LOS, but otherwise similar outcomes. Investigating reasons for increased complication and healthcare utilization likelihood among these subgroups is warranted.

Comparison of Complication Risks Following Lower Extremity Free Flap Reconstruction Based on Seven Pre-Operative Indications: Analysis of the ACS-NSQIP Database

Background: Free tissue transfer is a valuable surgical option for the reconstruction of a myriad of complex lower extremity defects. Currently, there is a paucity of data that examines the risks of complications for each of these unique indications. Methods: Patients undergoing lower extremity free flap reconstruction from the ACS-NSQIP 2011–2019 database were stratified into groups based on the etiology and indication for reconstruction. Rates of major, surgical wound, and medical complications were compared over the first post-operative month. Multivariable logistic regression was used to identify complication predictors. Results: 425 lower extremity free flaps were analyzed. The most common indications for lower extremity free flap reconstruction were wound-related (29%), malignancy (21%), and trauma (17%). Seventeen percent of free flaps had a major post-operative complication, 9% had a surgical wound complication, and 16% had a medical complication. There were no significant differences in major complications between the indications. However, the independent risk factors for major complications varied widely. Those with an indication of malignancy and those who received a musculocutaneous free flap were significantly more likely to have a surgical wound complication compared to the remaining cohort ( p < 0.05). Those requiring free flap reconstruction for orthopedic hardware related concerns as well as those with wound related indications were significantly more likely to have a post-operative medical complication ( p < 0.05). Conclusion: Understanding the unique risk profiles between the various indications and populations of patients undergoing lower extremity free flap reconstruction is critical for providing accurate risk estimations and optimizing post-operative outcomes and monitoring.

Approach to Complex Lower Extremity Reconstruction

Composite injuries to the lower extremity from etiologies including trauma and infection present a complex dilemma for the reconstructive surgeon, and require multidisciplinary collaboration amongst plastic, vascular, and orthopaedic surgical specialties. Here we present our algorithm for lower-extremity reconstructive management, refined over the last decades to provide an optimized outcome for our patients. Reconstruction is predicated on the establishment of a clean and living wound, where quality of the wound-bed is prioritized over timing to soft-tissue coverage. Once established, soft-tissues and fractures are provisionally stabilized; our preference for definitive coverage is for microvascular free-tissue, due to the paucity of healthy soft-tissue available at the injury, and ability to avoid the zone of injury for microvascular anastomosis. Finally, definitive bony reconstruction is dictated by the length and location of long-bone defect, with a preference to utilize bone transport for defects longer than 5 cm.

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.

Free gracilis end-to-side microanastomosis to a peronea arteria magna: a case report

BACKGROUND

Complex orthoplastic lower limb trauma in individuals with multiple injuries requires considerable resources and interdisciplinary collaboration for good outcomes. We present the first reported end-to-side free flap microanastomosis for lower limb trauma reconstruction involving a peronea arteria magna without radiographic collaterals.

CASE PRESENTATION

A 55-year-old Caucasian gentleman involved in road traffic collision sustained an open tibial fracture on the anteromedial distal third of the left lower leg with local degloving and a subtotal right foot and ankle degloving. Both injuries were reconstructed with free tissue transfer. A left lower limb peronea arteria magna successfully received a free gracilis muscle flap by end-to-side microanastomosis and perfusion of the foot was preserved. This rare anatomical variant and its anatomy is reviewed, as well as a description of the suggested preoperative planning and technique for reconstruction.

CONCLUSIONS

Successful free flap reconstruction may be performed to a lower limb with a peronea arteria magna recipient as the lone vessel supplying the foot in trauma, although preoperative counseling of the risks, benefits, and options are essential.

LEVEL OF EVIDENCE

Level V, case report.

Orthoplastics in Periprosthetic Joint Infection of the Knee: Treatment Concept for Composite Soft-tissue Defect with Extensor Apparatus Deficiency

Introduction: Reconstruction of composite soft-tissue defects with extensor apparatus deficiency in patients with periprosthetic joint infection (PJI) of the knee is challenging. We present a single-centre multidisciplinary orthoplastic treatment concept based on a retrospective outcome analysis over 20 years. Methods and Results: One-hundred sixty patients had PJI after total knee arthroplasty. Plastic surgical reconstruction of a concomitant perigenicular soft-tissue defect was indicated in 47 patients. Of these, six presented with extensor apparatus deficiency. One patient underwent primary arthrodesis and five patients underwent reconstruction of the extensor apparatus. The principle to reconstruct missing tissue 'like with like' was thereby favoured: Two patients with a wide soft-tissue defect received a free anterolateral thigh flap with fascia lata; one patient with a smaller soft-tissue defect received a free sensate, extended lateral arm flap with triceps tendon; and two patients who did not qualify for free flap surgery received a pedicled medial sural artery perforator gastrocnemius flap. Despite good functional results 1 year later, long-term follow-up revealed that two patients had to undergo arthrodesis because of recurrent infection and one patient was lost to follow-up. Conclusion: These results show that PJI of the knee and extensor apparatus deficiency is a dreaded combination with a poor long-term outcome. Standardization of surgical techniques for a defined PJI problem and consensus on study variables may facilitate interinstitutional comparisons of outcome data, and hence, improvement of treatment concepts.

Anastomotic Technique and Preoperative Imaging in Microsurgical Lower-Extremity Reconstruction: A Single-Surgeon Experience

BACKGROUND

The need for preoperative imaging as well as anastomotic technique (ie, end-to-side [ETS] vs end-to-end [ETE]) are areas of controversy in microsurgical lower-extremity reconstruction. The objective of this study was to (1) investigate whether preoperative imaging is mandatory and (2) to elicit if the type of anastomosis impacts clinical outcomes.

METHODS

A retrospective review of all patients who underwent microvascular lower-extremity reconstruction between 2007 and 2015 by a single surgeon was performed. Patients were categorized into groups based on anastomotic technique, that is, ETE versus ETS anastomosis. Patients in the ETE group were further subclassified into those who had preoperative imaging (computed tomography angiography [CTA]+) versus those who did not (CTA-). Parameters of interest included flap type, thrombosis rate, flap loss, length of stay (LOS), return to ambulation, and rate of secondary amputation. Two-sided statistical analysis was performed using Kruskal-Wallis rank-sum test and Fisher exact test.

RESULTS

One hundred twenty-eight patients were analyzed: ETE (n = 40) and ETS (n = 88). Mean follow-up for both groups was 20 ± 19 months. Anterolateral thigh flaps were most commonly performed (71%). Overall flap loss rate was 3.1% without any significant differences noted with respect to thrombosis (arterial, P = 0.09; venous, P = 0.56), flap loss (P = 0.33), LOS (P = 0.28), amputation (P = 1.00), or return to ambulation (P = 0.77). Furthermore, the availability of preoperative imaging (CTA+: N = 11 vs CTA-: N = 29) did not impact rates of thrombosis (arterial, P = 0.29; venous, P = 0.31), flap loss (P = 1.00), LOS (P = 0.26), or return to mobility (P = 0.62).

CONCLUSIONS

In light of similar reconstructive outcomes, we prefer to preserve distal extremity perfusion via ETS anastomoses whenever possible. Furthermore, preoperative vascular imaging angiography might not be necessary in patients with palpable pedal pulses on preoperative examination. An actionable algorithm for determining ETS versus ETE anastomosis in lower-extremity reconstruction is presented.

Reconstruction of Deep Burn Wounds Around the Ankle With Free Fascia Flaps Transfer and Split-Thickness Skin Graft

We aimed to introduce a technique by combining free fascia flaps transfer with split-thickness skin graft for the reconstruction of deep burn wounds at the ankle. Fifteen patients from 2009 to 2016 were enrolled in this study. Patients in this series suffered from a deep burn injury around the ankle, which was accompanied with exposure of tendon and medial or lateral malleolus exposure due to severe soft-tissue defects (N = 15). All the 15 wounds were repaired combining free fascia flaps with split-thickness skin graft operations, including nine anterolateral thigh fascia lata flaps (ATFL flaps) and six superficial temporal fascia flaps (STF flaps). All the fascia flaps completely survived. Two patients showed partial grafting skin necrosis due to either wound infection or subcutaneous hematoma infection, and this was eventually healed satisfactorily after conventional dressing change. All patients achieved esthetic outcome and acceptable functionality without further revisions needed. Our present study reports a useful method that involves using free fascia flaps in combination with split-thickness skin graft to repair deep burn wounds around the ankle. This method provided reliable and durable soft-tissue coverage with good outcomes.

Variables associated with 30-day postoperative complications in lower extremity free flap reconstruction identified in the ACS-NSQIP database

BACKGROUND

Lower extremity free flaps are a common way to treat both traumatic and oncologic lower extremity wounds. These patients often suffer postoperative complications. We sought to use the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to identify variables associated with postoperative complications.

METHODS

Patients who had free flap procedure and a primary diagnosis code for lower extremity pathology were identified in the NSQIP database from 2006 to 2017. NSQIP includes data on preoperative, intraoperative, and postoperative variables, including information up to 30 postoperative days. Current procedural terminology (CPT) codes for free flaps and international classification of diseases (ICD) 9 and 10 codes for lower extremity pathology were used for our cohort. We examined overall and major complication rates. Major complications were defined as reoperation, readmission, organ space infection, or death. Univariate and multivariate analyses were used to identify associations with complications.

RESULTS

Four hundred and eighty-three patients underwent lower extremity free flaps. Overall complication rate was 31.6% and major complication rate was 14.9%. Prolonged operative time (OR = 2.81, CI:1.76-4.48, p < .001), preoperative steroid use (OR = 3.04, CI:1.12-8.29, p = .030), and preoperative anemia (OR = 4.10, CI:2.00-8.41, p < .001) were independently associated with any complication. Diabetes (OR = 2.56, CI:1.24-5.29, p = .011) and prolonged operative time (OR = 3.75, CI:2.17-6.47, p < .001) were independently associated with major complications.

CONCLUSIONS

In lower extremity flap reconstruction, associations with overall complications include prolonged operative time, steroid use, and anemia. Associations with major complications included diabetes and prolonged operative time. These associations can be used to guide interventions on patients identified to have greater risk of complications.

Pedicled and Free Tissue Transfers

Tissue defects that result from diabetic foot infections are often complex and necessitate reconstructive soft-tissue surgery to achieve closure. Intrinsic muscle flaps of the foot require attention to major vascular pedicles and are useful for closing smaller ulcerations. Microvascular free flaps are beneficial for large defects and provide long-term survivability. Perioperative planning is an important aspect of caring for diabetic patients requiring reconstructive surgery. These techniques are valuable tools for use in efforts to preserve a functional limb in this patient population.

Free flap and kickstand external fixator in foot and ankle soft tissue reconstruction. The versatility of a microsurgical-friendly application of an orthopedic device

INTRODUCTION

Foot and ankle are prone to injuries and often require free flap for complex soft tissue reconstruction due to the insufficiency of local soft tissue. Lower limb reconstruction can be commonly compromised by venous insufficiency, and the elevation of the limb represents a critical component of the postoperative care. This study aims to explore the versatility of combining free soft tissue flap reconstruction for complex foot and ankle defect with a temporary Kickstands External Fixator (KEF) placement.

MATERIALS AND METHODS

A retrospective analysis was performed on 14 patients with unilateral foot or ankle complex soft tissue defects (post-traumatic, soft tissue infection and osteomyelitis, chronic skin ulcer, sarcoma), treated with free flap and KEF placement. Patients' demographics, etiology of injury, type of reconstruction, duration of KEF, complications related to the flap and the KEF placement were recorded.

RESULTS

The mean age of patients was 52.57-year-old (range 35-68). The average follow up was 15.5 months (range: 3-25). An anterolateral thigh (ALT) flap was performed in 12 patients; 2 patients received composite forearm free flap plus flexor carpalis radial for Achilles tendon reconstruction. The average time for KEF removal was 378 weeks. All flaps survived, though partial necrosis was observed in 1 case. No complication at the flap donor site or related to the KEF placement was observed. No equinus deformity was reported.

CONCLUSION

The KEF placement when performing a complex soft tissue free flap reconstruction of foot and ankle could be an effective method to guarantee limb elevation, avoid pressure on the flap especially in posterior reconstructions, avoid heel pressure ulcer formation and equinus deformity.

Reconstruction of the plantar toe with a distal reverse instep sensory island flap

BACKGROUND

Plantar toe ulcers are a challenging surgical problem. There are several methods for reconstruction, but no attention has been given to the preservation of sensation. This report proposes a method to provide protective sensation for the reconstructed area.

PATIENTS AND METHODS

The ulcers of seven patients ranged from 2 × 3 to 7 × 3 cm with defects of the plantar first toe and distal metatarsus, including four burns, a trauma, a diabetic ulcer, and a neuropathy injury reconstructed with a distal reverse instep sensory island (DRISI) flap. The patients were 21-38 years old. The second metatarsus medial nerve was co-opted using the end-to-side method to the adjacent lateral nerve, then its proximal stump provided the donor nerve for the sensation of the flap. Patients were assessed in terms of protective sensory functions, including touch, pain, dermatomeric somatosensory-evoked potentials (SEP), thermal sensation and Semmes-Weinstein monofilament (SWM) light touch.

RESULTS

The flaps ranged from 2 × 3 to 7 × 3 cm. All transferred flaps to the plantar first toe survived. No complications were observed at the donor and flap sites. Patients were followed-up 8-24 months. Except for two cases, all nerves of the donor and flap sites exhibited protective sensation, including positive SEP responses between 44 and 50 ms and positive SWM responses ≤ 3.84.

CONCLUSION

The DRISI flap can be used for the reconstruction of various plantar first toe defects with acceptable protective sensation. End-to-side neurorrhaphy provides a sensory nerve end to subsequent end to end co-optation to the flap nerve for protective sensation.

Preoperative Platelet Count Predicts Lower Extremity Free Flap Thrombosis: A Multi-Institutional Experience

BACKGROUND

Thrombocytosis in patients undergoing lower extremity free tissue transfer may be associated with increased risk of microvascular complications. This study assessed whether preoperative platelet counts predict lower extremity free flap thrombosis.

METHODS

All patients undergoing lower extremity free tissue transfer at Duke University from 1997 to 2013 and at the University of Pennsylvania from 2002 to 2013 were retrospectively identified. Logistic regression was used to assess whether preoperative platelet counts independently predict flap thrombosis, controlling for baseline and operative factors.

RESULTS

A total of 565 patients underwent lower extremity free tissue transfer, with an overall flap thrombosis rate of 16 percent (n = 91). Elevated preoperative platelet counts were independently associated with both intraoperative thrombosis (500 ± 120 versus 316 ± 144 × 10/liter; p < 0.001) and postoperative thrombosis (410 ± 183 versus 320 ± 143 × 10/liter; p = 0.040) in 215 patients who sustained acute lower extremity trauma within 30 days before reconstruction. In acute trauma patients, preoperative platelet counts predicted a four-fold increased risk of intraoperative thrombosis (cutoff value, 403 × 10/liter; OR, 4.08; p < 0.001) and a two-fold increased risk of postoperative thrombosis (cutoff value, 361 × 10/liter; OR, 2.16; p = 0.005). In patients who did not sustain acute trauma, preoperative platelet counts predicted a four-fold increased risk of intraoperative thrombosis (cutoff value, 352 × 10/liter; OR, 3.82; p = 0.002).

CONCLUSIONS

Acute trauma patients with elevated preoperative platelet counts are at increased risk for lower extremity free flap complications. Prospective evaluation is warranted for guiding risk stratification and targeted treatment strategies.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Aesthetic Multiple-Toe Reconstruction With Combined Iliac Bone Graft and Wraparound Free Anterolateral Thigh Flap-A Case Report and Literature Review

Compared with upper extremity injuries, toe amputations and their replantations are rare because of the difficulty of their relatively thinner soft tissue envelope. Consequently, fewer reconstructive options are available for toes and they are rarely reported in the literature. In this study, we reported a case of right third to fifth toe amputations and their subsequent reconstruction with iliac bone grafts and a free anterolateral thigh flap. After serial debulking and division procedures, 3 toes were divided successfully. Ten months after the initial operation, the patient regained pain-free functional ambulation despite some bone resorption noted on follow-up radiographs. The patient showed high satisfaction on her new toes in terms of aesthetical and functional outcomes. She was able to stand for over 30 minutes without pain. At the 2-year follow-up, the Foot Function Index was 18.3%. Although toe reconstruction is frequently considered unnecessary because of its relative high demand of surgical techniques and little gain on gait; nonetheless, in selected cases, toe reconstruction may still be beneficial if the metatarsophalangeal joints were intact and there is a strong individual desire for aesthetical restoration.