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

One vs. two-stage arteriovenous loops in lower extremity reconstruction with free flaps: Systematic review and metanalysis

BACKGROUND

Arteriovenous loops are one of the main therapeutic alternatives to address the absence of recipient vessels in lower extremity microsurgical reconstruction. However, there is no consensus on whether to perform them in one or two surgical stages. The objective of this work is to determine whether the outcome of lower limb free flaps anastomosed to vascular loops depends on the number of surgical stages.

MATERIALS AND METHODS

A literature review was conducted, following PRISMA guidelines, on vascular loops and free flaps in lower limb. Survival rate, as well as major and minor complications were studied. A forest plot and Pearson's chi-square were used for statistical analysis. Study quality was assessed in duplicate using Methodological Index for Non-Randomized Studies (MINORS) and Joanna Briggs Institute (JBI) tool. This study was registered on PROSPERO.

RESULTS

Thirty-two articles using free flaps anastomosed to vascular loops in lower limb, either one or two-stage, were selected. A total of 296 flaps were included, 52% (n = 154) in one and 48% (n = 142) in two surgical times. No statistically significant differences were found in the survival rate (OR = 1.85, 95% CI 0.62; 5.47, p = .09 and p = .344) or major complications (OR = 0.70, 95% CI 0.31; 1.57, p = .56 and p = .92) of flaps between both groups.

CONCLUSIONS

According to the available evidence, the outcome of free flaps anastomosed to vascular loops in the lower limb does not depend on the number of surgical stages they undergo. Although there is some heterogeneity in the groups studied, the decision on the number of procedures to be performed should be determined by the surgeon, concerning the clinical situation of the patient, as well as to the vascular, bone and soft tissue status of the extremity.

The use of a skin paddle-containing vein graft for arteriovenous looping in two-stage free flap reconstruction of lower extremities

BACKGROUND

Arteriovenous (AV) looping prior to the lower extremity free flap reconstruction enables better venous drainage in flap circulation, leading to less flap complications and better survival. A two-staged reconstruction including free tissue transfer after AV looping ensures a robust venous drainage of the flap. Arterialization of the AV loop results in less venous problems after the free flap reconstruction. However, major problems of this staged operation include AV loop kinking, heavy compression and loop exposure, leading to AV graft failure and interruption of surgical planning. The purpose of this article is to summarize probable flaws we noticed in conventional two-stage lower limb reconstruction and overcome those problems using the skin paddle-containing vein graft.

METHOD

Eight patients with lower limb defects underwent lower limb reconstruction surgery using this technique at our institute. The mean age was 52 years old. Of the eight patients, three of them have the defect due to infection. Three of them was due to trauma and three of them was due to full-thickness burn. Five of the defects located at foot. The other three defects located at heel, knee, and pretibial region. All of them require AV looping because of unavailability of nearby recipient vessels. They all received a two-stage operation, including the first stage AV looping with a skin paddle-containing vein graft and the second stage definite free tissue transfer.

RESULTS

The mean defect size was 140 cm2 (72-225). The mean length of AV loops was 17.1 cm (8-25). The mean size of skin paddles for vein grafts was 19.4 cm2 (15-24). The mean size of free ALT flaps 154.4 cm2 (105-252). All eight patients experienced a smooth postoperative course with no major or minor complications. There were no graft thrombosis or graft rupture complications during the vascular maturation period. All eight AV loops survived during maturation. All eight patients progressed to the second stage surgery. Maturation time ranged from 5 to 7 days. Free ALT flap was employed during the second stage reconstruction. All flaps survived at the last follow-up visit. There was no partial flap loss and complications. The mean follow-up time was 12.25 months, ranging from 8 to 17 months.

CONCLUSION

The skin paddle-containing vein graft is an effective modification of the regular vein graft for AV looping procedure. The skin paddle prevents the underlying AV loop from compression, kinking and twisting during maturation. It also aids assessing patency of the AV loop and avoids the formation of adhesion between the AV loop and the surrounding tissue.

Combined Revascularization and Free Flap Reconstruction for Chronic Limb-Threatening Ischemia: A Systematic Review and Meta-Analysis

BACKGROUND

 Combined revascularization and free flap reconstruction is one treatment method for chronic limb-threatening ischemia (CLTI) with complex wounds. The purpose of this systematic review and meta-analysis was to investigate the characteristics of this combined procedure and to assess postoperative outcomes.

METHODS

 A systematic search was performed across PubMed, Scopus, and the Web of Science for studies between January 2000 and February 2022. A random-effects meta-analysis for postoperative outcome was conducted.

RESULTS

 Fifteen articles encompassing 1,176 patients with 1,194 free flaps were ultimately included in the qualitative and quantitative assessment. Our meta-analysis showed the following complication rates for short-term postoperative outcomes: 37% (95% confidence interval [CI], 18-53%; I 2 = 74%) for reoperation, 13% (95% CI, 2-24%; I 2 = 0%) for vascular thrombosis, 9% (95% CI, 0-17%; I 2 = 0%) for total flap failure, 8% (95% CI, 0-17%; I 2 = 0%) for partial flap failure, 4% (95% CI, 0-10%; I 2 = 0%) for amputation, and 3% (95% CI, 0-9%; I 2 = 0%) for 30-day mortality. The 1-, 3-, and 5-year limb salvage rates were 86% (95% CI, 78-92%), 81% (95% CI, 68-88%), and 71% (95% CI, 53-83%), respectively. The 1-, 3-, and 5-year patient survival rates were 93% (95% CI, 90-96%), 92% (95% CI, 77-97%), and 75% (95% CI, 50-88%), respectively.

CONCLUSION

 Combined revascularization and free flap reconstruction for CLTI with complex wounds was clearly effective for the long-term outcomes. However, this combined procedure should be considered on the assumption that the reoperation rate is high and that flap-related complications rate may be higher than lower extremity reconstruction of other etiologies.

Flaps for lower limb diabetic wound reconstruction: A systematic review and meta-analysis

BACKGROUND

The treatment of chronic diabetic wounds includes wound dressing, debridement, flap surgery, and amputation. For suitable patients with nonhealing wounds, locoregional flaps or free flaps may be used. This paper aims to review the outcomes of flap surgery and identify the risk factors for flap loss.

METHODS

MEDLINE, Embase, and Cochrane Library were searched. Articles reporting flap loss outcomes for flap surgery in lower limb chronic diabetic wounds were included. Case reports and case series with fewer than five patients were excluded. A subset of articles was used for revascularization subgroup analysis and another subset for meta-analysis of risk factors for flap loss.

RESULTS

In the free flap group, the total flap failure rate was 7.14% and partial flap failure rate was 7.54%. The rate of major complications requiring operative takeback was 19.0%. Early mortality was 2.76%. In the locoregional flap group, the total flap failure rate was 3.24% and partial flap failure rate was 5.36%. The rate of major complications requiring operative takeback was 13.3%. There was no early mortality. The rate of free flap loss was 18.2% with revascularization, significantly higher than 6.66% without revascularization.

CONCLUSIONS

Our findings concur with previously published studies on flap loss and complications in diabetic lower limb wounds. There is an increased risk of flap loss in patients who require free flap and revascularization compared to patients who only require free flap. This could be because of the fragile and fibrotic vessels found in diabetics with comorbid atherosclerosis.

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.

One-Stage versus Two-Stage Arteriovenous Loop Reconstructions: An Experience on 103 Cases from a Single Center

BACKGROUND

The optimal time for flap anastomosis to an arteriovenous loop remains controversial. Whether perforator flaps and axially vascularized muscle or fasciocutaneous flaps lead to comparable outcomes in conjunction with arteriovenous loops has not been investigated.

METHODS

Medical records from 103 patients undergoing arteriovenous loop reconstruction (76 one-stage and 27 two-stage) between 2007 and 2017 were reviewed. Postoperative outcomes were compared between one- and two-stage arteriovenous loop reconstructions and different types of free flaps.

RESULTS

Rates of flap thrombosis, major wound complications, and flap failure did not differ significantly between one- and two-stage arteriovenous loop reconstructions (14.47 percent versus 11.11 percent, p = 1.00; 30.26 percent versus 25.93 percent, p = 0.67; and 10.53 percent versus 7.41 percent, p = 1.00). For two-stage arteriovenous loop reconstructions, the time interval between arteriovenous loop placement and flap anastomosis was a predictor for thrombotic events (OR, 1.31; p < 0.05). Anterolateral thigh flaps in conjunction with arteriovenous loops showed higher failure rates (33.33 percent) compared with all other flaps (6.59 percent) (p < 0.05) and combined latissimus dorsi and parascapular flaps (0 percent) (p < 0.05). Thrombosis rates were higher in anterolateral thigh flaps (33.33 percent) compared with all other flaps (10.99 percent; p = 0.056), and combined latissimus dorsi and parascapular flaps (0 percent; p < 0.05).

CONCLUSIONS

Two-stage arteriovenous loop reconstructions do not lead to increased postoperative complications compared to one-stage arteriovenous loop reconstructions and may be favorable in complicated cases because of shorter operative times. To avoid an increased thrombosis risk, flap anastomosis should not be delayed beyond 10 days in two-stage arteriovenous loop reconstructions. Anterolateral thigh flaps are less suitable for arteriovenous loop reconstructions because of higher complication rates.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Retrospective cohort study of combined approach for trunk reconstruction using arteriovenous loops and free flaps

Defect reconstruction of the trunk can be performed using microsurgical free flap transplantation. In cases of missing or inappropriate recipient vessels, microsurgical defect reconstruction of the trunk can be achieved by combining free flaps with arteriovenous loops. Here we present our 5-year experience of trunk reconstruction using AV loops and free flaps in a retrospective evaluation. We analyzed 32 cases of trunk reconstruction using a combined approach of free flap transplantation and arteriovenous loops between 2011 and 2016 regarding postoperative complications and perioperative course. Twenty-one patients suffered from sternal defects, 4 from presacral defects, 3 patients presented with lateral chest wall defects, 2 patients suffered from lumbosacral defects, 1 patient had a gluteal defect and 1 patient a defect at the clavicle. In all cases, free flap transplantation and arteriovenous loop creation were performed in a two-stage procedure. There were 8 thromboses of the arteriovenous loops with 4 flap failures. Only 1 flap loss was located in the sternal region, whereas one presacral flap and both lumbosacral flaps were lost. Reconstruction of large soft tissue defects of the trunk by a combined approach with an arteriovenous loop creation and consecutive free flap transplantation represents a reliable procedure in ventral and posterior cranial localization, whereas in the caudal posterior region, AV loop thrombosis can occur. Therefore, to minimize flap loss, a two-stage procedure should be performed.

Combination of Vascular Intervention Surgery and Free Tissue Transfer for Critical Diabetic Limb Salvage

BACKGROUND

Complex, nontraumatic diabetic foot ulcers with peripheral vascular compromise often lead to extensive lower-limb amputation. The aim of this study is to determine the outcome of combined vascular intervention and free tissue transfer for critical diabetic limb salvage.

MATERIALS AND METHODS

A total of 26 consecutive diabetic patients with 28 legs with diabetic foot ulcers who underwent limb salvage with a combination of revascularization (bypass surgery or endovascular angioplasty) and free flap transfers were reviewed. There were 14 male and 12 female patients. The average age was 58.8 years (range, 35-85 years). Amputation-free survival and complete wound healing were defined as the primary endpoints. All preoperative and postoperative data were retrospectively analyzed.

RESULTS

Thirty flaps were used for reconstruction in 28 legs, including 21 free anterolateral thigh (ALT) perforator flaps, 3 ALT myocutaneous flaps, 5 gracilis muscle flaps, and 1 latissimus dorsi muscle flap. All flaps used end-to-side anastomoses for the recipient artery and end-to-end anastomoses for the recipient vein. The overall flap success rate was 90% (27/30). Two flaps failed completely because of severe arteriosclerosis, which resulted in anastomosed vessel thrombosis. New flaps were applied in both cases after debridement and trimming of necrotic tissue. One flap failed because of restenosis and inadequate perfusion combined with severe infection, resulting in pedicle thrombosis. A below-knee amputation was subsequently performed. Seven flaps exhibited a partial loss, including 6 ALT perforator flaps and 1 latissimus dorsi flap, because of inadequate margin perfusion. After debridement, the flap revision and wound care, 5 flaps healed uneventfully without additional intervention. The remaining 2 ALT perforator flaps required debridement with a skin graft. The limb-salvage rates were 92.8% after 1 year and 89.2% after 5 years.

CONCLUSIONS

The combination of peripheral arterial intervention and free tissue transfer resulted in successful wound healing and limb salvage instead of amputation in select diabetic patients with difficult-to-heal wounds.

Utility of arteriovenous loops before free tissue transfer for post-traumatic leg defects

Crush injuries of severe magnitude involving lower limbs require complex bone and soft tissue reconstructions in the form of microvascular free tissue transfers. However, satisfactory recipient vessels are often unavailable in the leg due to their vulnerability to trauma and post traumatic vessel disease (PTVD), which extends well beyond the site of original injury. In such situations, healthy recipient vessels for free flap anastomosis can be made available by constructing temporary arteriovenous loops with saphenous vein grafts, anastomosed to corresponding free flap vessels. Our study included 7 patients with severe crush injuries of leg due to rail and road traffic accidents. Long and short saphenous vein grafts were anastomosed to Femoral artery in the subsartorial canal in 2 cases and to large muscular branches and accompanying veins in rest of the cases. Free flap transfers were performed in the same sitting in 6 cases. One case showed insufficient dilatation of the vein loop and hence free flap transfer was staged. Free Latissimus dorsi, Gracilis and Rectus abdominis flaps were performed. There were two cases of flap necrosis – one in the case of a pathologic vein graft with staged flap transfer which showed vein thrombosis on re exploration. The other case of flap failure was caused by a hematoma underneath the flap. In another patient, secondary haemorrhage occurred on day 18, without any consequence to the flap. All the other cases had complete free flap survival. We consider the use of single stage arteriovenous loops, a valuable tool to increase the applications of free flap, whenever healthy recipient vessels are not available in the periphery of the trauma.

Arteriovenous loop grafts for free tissue transfer

Arteriovenous (AV) loop grafts are a type of vascular conduit that can be used to support free tissue transfer. Wounds of various etiologies may require free tissue transfer, and the AV loop graft is a useful adjunct when adjacent blood supply is inadequate. Here we present 2 cases and review the technique and published literature.

Flap reconstruction of distal lower extremity wounds in diabetic patients

Lower extremity diabetic wounds have been a challenge to clinical surgeons because of the higher risk of limb ischemia, soft-tissue infection, and soft-tissue loss caused by the pathology of the disease. In the published data, the most commonly used reconstruction techniques include pedicled flaps, microsurgical muscle or musculocutaneous flaps, and microsurgical fasciocutaneous or perforator flaps. However, there is still no consensus about which type of flap should be preferred among various reconstructive options. It is therefore the aim of this study to review current articles describing distal lower extremity flap reconstruction in patients with diabetes to survey reported results from the literature.

[Free tissue transfers with lengthening of vascular pedicle using interpositional vein grafts. About 10 cases]

The realization of free flaps with lack of reliable vessels nearby the loss of substance is a difficult problem for plastic surgeons. We report 10 cases of free tissue transfers with a one-stage technique lengthening the vascular pedicle of the free flap with interpositional vein grafts. Taking into consideration the good results and the low rate of morbidity, the authors emphasize the use of this technique rather than a two-stage procedure.

Single stage arteriovenous short saphenous loops in microsurgical reconstruction of the lower extremity

The short saphenous vein can be used "in situ" to create a temporary arteriovenous shunt for lengthening the recipient vessels of the injured limb in microsurgical reconstructions of the lower extremity. We report our results using this single-anastomosis turnover technique in three high-energy trauma patients who presented open tibial fractures associated with vascular injuries. The construction of the arteriovenous fistula provided arterial access and venous drainage to a free latissimus dorsi flap that was transferred to cover the soft tissue defect. In all three cases, this single stage procedure was successful; the flap survived and provided good long term results. The use of the ipsilateral small saphenous vein "in situ" for immediate arteriovenous loop formation may be of great value in complex lower leg reconstructions. It is a reliable adjunctive technique that provides healthy vessels to supply the free flap, permitting stable wound coverage and high rate of limb salvage.