Free vascularized tissue transfer for limb salvage in peripheral vascular disease

Evaluation of the Suprafascial Thin ALT Flap in Foot and Ankle Reconstruction

BACKGROUND

 Distal lower extremity reconstruction can be challenging in terms of flap design. Bulky flaps result in limited mobility accompanied with the need of customized footwear. Raising the ALT-flap in a superficial fascial plane (thin ALT-flap) can be beneficial. This study evaluates thin ALT-flaps for lower distal extremity reconstruction.

METHODS

 In a retrospective study, patients that underwent microvascular extremity reconstruction at the level of the ankle and dorsal foot at the University of Freiburg from 2008-2018 were reviewed.

RESULTS

 95 patients could be included in the study (35 perforator flaps, 8 fascia flaps and 54 muscle flaps).Among the perforator flaps, 21 ALT-flaps were elevated conventionally and 14 in the superficial fascial plane (thin ALT-flap). Among the conventional ALT-flaps, there was one flap loss (5%) and one successful revision (5%). 5(24%) flaps received secondary thinning. 57%(n = 12) were able to wear conventional footwear. There were 2(15%) successful revisions of thin ALT-flaps. 100% of thin ALT-flaps survived and 85%(n = 11) of the patients wore ordinary footwear after defect coverage.Among fascial flaps, 50%(n = 4) had to be revised with 2(25%) complete and 1 (13%) partial flap loss. All patients achieved mobility in ordinary shoes (n = 8).In muscle flaps, there were 7(13%) revisions and 5(9%) flap losses. 5(9%) flaps received secondary thinning. Only 33%(n = 18) were mobile in ordinary footwear.

CONCLUSION

 The thin ALT-flap is a save one-stage evolution for lower distal extremity reconstruction with a favorable flap survival rate. Compared with conventional ALT-flaps it might be beneficial in reducing the need for expensive custom fitted shoes and secondary thinning procedures.

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.

THE DESIGN OF THE ARTERIOVENOUS VASCULAR LOOP DOES NOT AFFECT ITS PATENCY: EXPERIMENTAL STUDY

OBJECTIVE

To evaluate the effect of the design of a femoral vascular loop with anastomosis in the femoral artery of rabbits on the presence of flow (patency) after seven days.

METHODS

A total of 39 rabbits underwent arteriovenous microanastomosis using the microsurgical technique. Two loop designs were used: one circular and the other angled. The parameters evaluated were presence or absence of flow, signs of hemolysis and hemodynamic changes.

RESULTS

After seven days, flow was present in 68% of the angled loops and 75% of the circular loops (p > 0.05). There was a significant intragroup decrease in pCO₂ and a significant increase in pH. For the other parameters evaluated, no significant differences between the two loop models were found.

CONCLUSIONS

A reproducible vascular loop model was shown. There was no significant difference between the two vascular loop models about the presence of flow after seven days. Level of Evidence V, Animal experimental study.

Flap decisions and options in soft tissue coverage of the lower limb

THE LOWER EXTREMITIES OF THE HUMAN BODY ARE MORE COMMONLY KNOWN AS THE HUMAN LEGS, INCORPORATING: the foot, the lower or anatomical leg, the thigh and the hip or gluteal region. The human lower limb plays a simpler role than that of the upper limb. Whereas the arm allows interaction of the surrounding environment, the legs' primary goals are support and to allow upright ambulation. Essentially, this means that reconstruction of the leg is less complex than that required in restoring functionality of the upper limb. In terms of reconstruction, the primary goals are based on the preservation of life and limb, and the restoration of form and function. This paper aims to review current and past thoughts on reconstruction of the lower limb, discussing in particular the options in terms of soft tissue coverage. This paper does not aim to review the emergency management of open fractures, or the therapy alternatives to chronic wounds or malignancies of the lower limb, but purely assess the requirements that should be reviewed on reconstructing a defect of the lower limb. A summary of flap options are considered, with literature support, in regard to donor and recipient region, particularly as flap coverage is regarded as the cornerstone of soft tissue coverage of the lower limb.

Extensive Revascularization or Primary Amputation: Which Patients with Critical Limb Ischemia Should Not Be Revascularized?

The commitment of vascular specialists to preserve the lower extremity has pushed the limits of revascularization. It is not uncommon for patients with severe distal disease to undergo extensive vascular reconstruction, bringing a bypass graft down to the ankle and beyond. Such procedures, when well-planned and well-executed, can result in a preserved and fully functional lower extremity with complete healing of all necrotic tissue. As noted in the guidelines presented by the TransAtlantic Inter-Society Consensus Working Group, there are patients who will benefit from primary amputation rather than extensive revascularization. Patients who are unable to tolerate the planned procedure or unlikely to have a functional extremity despite restoration of distal flow, should be considered for major amputation that eliminates the source of rest pain and all necrotic tissue. Although morbidity and mortality of major amputation continues to be significant, advances in prosthetic development and amputation technique can lead to preserved ambulatory ability and improved quality of life.

Arterial and Venous Reconstruction for Free Tissue Transfer in Diabetic Ischemic Foot Ulcers

OBJECTIVE

To review our experience with temporary arteriovenous (AV) fistula followed by free tissue transfer in the treatment of diabetic foot ulcers associated with peripheral arterial occlusion.

PATIENTS AND METHOD

From July 1997 to July 2002, 15 lower extremities were operated in 14 patients. An AV loop with its apex below the medial malleolus was created between popliteal artery and saphenous system. Three weeks later, the loop was divided to provide an artery and a vein end. Foot defect was covered with latissimus dorsi muscle flap followed by split thickness skin grafting.

RESULTS

Fistulas were patent in 12 extremities. Free tissue transfer was performed in 13 extremities. Two free flaps failed. After patent temporary arteriovenous fistula, free tissue transfer was successful in 11 of 12 extremities. One patient was amputated below knee due to ongoing infection despite successful free tissue transfer. Early mortality rate was 7%. Limb salvage was achieved in 11 of 13 extremities that staged operation was performed. Overall extremity loss was four of 15 lower extremities in 14 patients. Overall mortality was 21% for mean 20 follow-up period.

CONCLUSION

Temporary AV fistula and free flap may provide stable wound coverage and high rate of limb salvage in treatment of diabetic foot ulcers with large tissue loss.

Blood flow in a pedal bypass combined with a free muscle flap

OBJECTIVE

to assess the haemodynamic effect of a free muscle flap on the midterm success of a pedal bypass.

DESIGN

prospective consecutive study.

MATERIALS

a pedal bypass (autogenous vein graft) combined with a free muscle flap was performed in 13 patients with critical leg ischaemia. The feeding artery of the flap was anastomosed end-to-side to the bypass.

METHODS

blood flow was measured in the bypass before and after transplanting the flap. Doppler was used postoperatively to assess the patency.

RESULTS

the bypass and flap pedicle were patent in 11 cases six months postoperatively. Two grafts were thrombosed and the legs amputated. In the successful group the median (range) blood flow in the bypass was 50 (10-100) ml/min. It increased (p<0.05) after transplantation to 64 (20-113) ml/min, being 44 (14-97) ml/min distributed to the foot. Blood flow through the flap was 20 (6-37) ml/min. The two failing grafts had a flow of 30 and 51 ml/min before and 48 and 52 ml/min after transplantation, respectively. Blood flow through the flap was 47 ml/min and 36 ml/min, respectively. In the failure group the free flap received most of the blood supply through the bypass.

CONCLUSIONS

a free muscle flap connected to an infrapopliteal bypass increases the distal outflow bed and thus decreases the outflow resistance and increases graft flow.

Combined free tissue transfer and infrainguinal bypass graft: an alternative to major amputation in selected patients

OBJECTIVES

The purpose of this study was to document outcome and adverse prognostic factors in patients requiring combined free tissue transfer and distal bypass grafting for otherwise nonreconstructible infrainguinal arterial occlusive disease and advanced tissue necrosis.

METHODS

Between July 1990 and November 1999, 65 patients, all of whom would have required at least below-knee amputation, underwent free tissue transfer in conjunction with infrainguinal bypass grafting at the University of Rochester. Preoperative variables were assessed for their influence on outcome with chi(2) and outcome with life-table analysis with Cox proportionate hazard testing.

RESULTS

Free tissue transfer was performed synchronously with arterial reconstruction with autologous vein in 49 patients and after a previous functioning venous bypass graft in 16 patients. The 30-day mortality rate was 5%, and major complications occurred in another 16% of patients. Flap location, weight-bearing status, preexisting osteomyelitis, and the timing of bypass grafting relative to flap construction had no effect on outcome. All five free flap failures occurred within the first 30 days. All other flaps subsequently survived, even in seven patients whose bypass grafts thrombosed. Five-year limb salvage and patient survival rates were 57% and 60%, respectively, and 65% of patients regained meaningful ambulation. The combination of diabetes and dialysis-dependent renal failure was the strongest predictor of overall limb loss (P <.005; relative risk = 4.0), and diabetes alone was the strongest predictor of death (P <.02; relative risk = 5.2).

CONCLUSION

Free tissue transfer combined with infrainguinal bypass grafting in selected patients is safe and effective. The combination of diabetes and chronic renal insufficiency, particularly the need for dialysis, is a powerful predictor of failure and should be considered a strong contraindication for this procedure.

Combined revascularization and microvascular free tissue transfer for limb salvage: a six-year experience

Atherosclerotic vascular disease causing extensive tissue loss of the lower extremities often results in primary amputation. Combined revascularization and free tissue transfer has been described as a method of extending limb salvage to these patients. The durability of this combined procedure remains unknown, thus the objective of this report is to describe the immediate and long-term results in a series collected over 6 years. From 1992 to 1998, 15 patients with a mean age of 60 years underwent combined revascularization and free tissue transfer. Mean ulcer size measured 45 cm(2) for a mean duration of 7.4 months preoperatively and 12 patients had exposed bone or tendon. Vascular reconstruction included popliteal (3), tibial (6), and pedal (6) bypass with concomitant myocutaneous free flap, using mostly rectus abdominis or latissimus dorsi muscle. There were no perioperative deaths. One patient suffered a nonfatal myocardial infarction. Two patients had a postoperative wound hematoma and one required vascular graft revision. Patients were followed for 4 to 75 months (mean = 23 months). Four patients have required amputations (3 early, 1 late), three of whom had preoperative renal failure. The limb salvage rate has been 72% at 36 months,

Combined arterial reconstruction and free tissue transfer for limb salvage

PURPOSE

Lower-extremity arterial anatomy that is insufficient for successful vein bypass grafting and major proximal foot wounds often lead to leg amputation in patients with severe ischemia. Free tissue transfer, which can provide limb salvage in these patients after arterial reconstruction, was studied.

METHODS

During a 45-month period, 21 patients who otherwise would have undergone leg amputation were treated with arterial bypass by means of vein grafting and free tissue transfer. Ages of the patients ranged from 40 to 73 years (average, 59 years); 18 of the 21 patients had diabetes mellitus; and all patients except one were men. Arterial reconstruction was performed from the femoral (nine of 21 patients) or popliteal artery (12 of 21 patients) to the posterior tibial (eight patients), dorsalis pedis (five patients), peroneal (three patients), popliteal (one patient), or anterior tibial artery (one patient), or directly to the free flap (three patients). The tissue transferred included latissimus dorsi (five patients), rectus abdominus (five patients), omentum (five patients), gracilis (two patients), radial forearm flaps (three patients), and a scapular flap (one patient). Foot defects were debrided, including the appropriate toe or transmetatarsal amputation, covered with the transferred flap, and then split-thickness skin grafted. Arterial flow for all flaps was through the vein grafts, with direct arterial anastomosis and with venous outflow through adjacent tibial veins.

RESULTS

All 21 procedures were successful initially, without operative mortality, but three failed within 4 weeks because of uncontrolled infection (two) or embolization from a remote site (one) and required below-knee amputation. Grafts remained patent in 18 procedures, and follow-up of this cohort ranged from 1 to 45 months (mean, 13.3 months). Two patients died, one after 4 months and one after 6 months, of unrelated illness; at the time of death, they had functioning grafts. The remaining 19 patients are alive. Of these, 15 have patent arterial grafts, all viable free flaps. Thus, limb salvage was accomplished in 18 of 21 (86%) patients who otherwise would have required below-knee amputation.

CONCLUSION

Patients destined for leg amputation despite aggressive traditional arterial bypass grafting methods can achieve limb salvage with the additional technique of free tissue transfer.

Free tissue transfer to extend the limits of limb salvage for lower extremity tissue loss

BACKGROUND

The extent of tissue loss amenable to primary healing after revascularization is unknown. Salvage of limbs with large soft-tissue defects with exposed tendon, joint, or bone lies beyond the limits of conventional techniques. We report our results using free tissue transfer as an adjunct to lower extremity vascular reconstruction in patients with complex ischemic or infected wounds.

METHODS

Retrospective chart review of patient and wound characteristics.

RESULTS

From January 1992 to June 1996, 585 procedures were performed in 544 patients, including 27 free flaps in 26 patients: 17 free flaps combined with distal bypass (7 staged, 10 simultaneous) and 10 isolated free flaps. Flap donor sites included radial forearm (8), latissimus dorsi (7), rectus abdominus (9), and scapula (3). Surgical indications included extensive ischemic/neurotrophic ulcers, and nonhealing vein graft harvest incision or transmetatarsal amputation site. Mean area of tissue loss was 70 cm2, mean ulcer duration was 5 months, and 92% of patients had exposed tendon, joint, or bone. During a mean follow-up of 14 months, 2 patients died of cardiopulmonary disease and 3 flaps failed, resulting in below-knee amputation. Six flaps were revised for graft stenosis (1), venous thrombosis (1), or flap edge necrosis (4). Limb salvage rate was 70% at 24 months by life-table analysis. Functional ambulation was achieved in 21 of 24 (88%) patients, including 7 of 8 with diabetes, end-stage renal disease, and heel ulcers.

CONCLUSION

In select ambulatory patients with large soft-tissue defects and exposed deep structures, functional limb salvage is obtainable in more than 80% of patients. For lesions not amenable to vascular reconstruction with conventional methods of wound coverage, free tissue transfer extends the limits of limb salvage and is a viable alternative to amputation.

Salvage of femoropedal bypass graft complicated by interval gangrene and vein graft blowout using a flow-through radial forearm fasciocutaneous free flap

We report the case of a 71-year-old man who had interval gangrene of his calf with subsequent vein graft blowout 3 months after undergoing a femoral-to-dorsalis pedis saphenous vein bypass grafting procedure. To provide wound coverage, restore vascular continuity, and preserve functional ambulation, a flow-through radial forearm fasciocutaneous free flap was interposed between cut ends of the bypass graft. Venous drainage of the flap was from the cephalic vein to the popliteal vein. At 1 month after the operation, the patient had complete wound healing and began to ambulate. At 11 months an asymptomatic high-grade stenosis in the distal radial artery segment of the reconstruction was successfully treated with percutaneous angioplasty. After 22 months of follow-up there have been no further complications, and the patient continues to have full, functional ambulation. The radial forearm flow-through free flap allows single-stage restoration of bypass graft continuity and coverage of extensive, complex tissue defects. This technique represents a novel approach to this difficult problem and provides a viable alternative to major limb amputation.

Combined vascular reconstruction and microvascular muscle flap transfer for salvage of ischaemic legs with major tissue loss and wound complications

OBJECTIVE

To assess the safety and short-term efficacy of combined vascular revascularisation and free microvascular muscle flap transfer in patients with advanced lower limb ischaemia caused by occlusive arterial disease.

DESIGN

A prospective follow-up study of 2-72 months.

SETTING

Academic referral centre.

MATERIALS

Consecutive first 15 patients with extensive tissue loss due to advanced leg ischaemia or wound complications after bypass surgery.

CHIEF OUTCOME MEASURES

Graft patency, free tissue transfer viability, amputation rate.

MAIN RESULTS

There was no perioperative mortality. The cumulative rates for secondary vascular patency, microvascular graft viability and limb salvage were 80%, 87% and 76% at one year provided that vessels and grafts that were functioning at the time of amputation were considered lost to follow-up rather than failed at that point. If, however, amputation was also regarded as vessel and graft failure the corresponding rates were 68%, 62% and 76%, respectively.

CONCLUSIONS

Combining microvascular muscle flap transfer with vascular reconstruction for salvage of legs with extended ischaemic tissue loss or wound complications after bypass surgery gave acceptable preliminary results and deserves an attempt in selected patients.