Does the use of arteriovenous loops increase complications rates in posttraumatic microsurgical lower extremity reconstruction?-A matched-pair analysis.

The use of arteriovenous (AV) loops in microsurgical lower extremity reconstruction is a controversial topic. The objective of the present study was to assess the impact of AV loops on complication rates following microsurgical reconstruction of posttraumatic lower extremity defects. Patients who underwent free flap coverage of posttraumatic defects in combination with an AV loop (Group 1) were identified and matched for age, body mass index (BMI), tobacco use, defect location, and flap type with patients who underwent reconstruction without vein grafts (Group 2). Outcomes of interest included complication rate and flap loss rate. Groups 1 and 2 consisted of 10 patients each with a mean age of 51 years (range, 21-79 years) and 47.3 years (range, 22-69 years), respectively (P = 0.596). No differences were noted regarding flap loss (P = 1.0), intraoperative (P = 0.474) or postoperative complication rate [surgical site infection (P = 1.0), bleeding (P = 1.0), delayed wound healing (P = 0.23), dehiscence (P = 0.58), and osseous non-union (P = 1.0)]. Only one flap loss was noted in Group 1. The only differences were increased operative time (P = 0.03) and increased length of stay (P = 0.009) in Group 1. Our results suggest that utilization of vein grafts with creation of AV loops followed by single-stage division and free flap transfer for reconstruction of posttraumatic lower extremity defects achieve reconstructive outcomes similar to those obtained in patients in whom no vein grafts are necessary.

Momeni A ，Lanni MA ，Levin LS ，Kovach SJ ... -  《-》

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

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. 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. 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. 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.

Brumberg RS ，Kaelin LD ，Derosier LC ，Hutchinson H ... -  《-》

The Impact of Increased Body Mass Index on Patient Outcomes and Complications in Microsurgical Lower Extremity Reconstruction.

Elevated body mass index (BMI) is a known perioperative risk factor for complications such as delayed wound healing and infection. However, there is a gap in understanding how elevated BMI impacts outcomes after posttraumatic lower extremity (LE) microvascular reconstruction. A retrospective review was performed at a level 1 trauma center between 2007 and 2022 of patients who underwent posttraumatic microvascular LE reconstruction. Demographics, flap/wound details, complications, and outcomes were recorded. Patients were stratified into BMI Center for Disease Control categories. A total of 398 patients were included with an average BMI of 28.2 ± 5.8. Nearly half (45%) of LE defects were located in the distal third of the leg, 27.5% in the middle third, and 34.4% in the proximal third. Most reconstructions utilized muscle-containing flaps (74.4%) compared with fasciocutaneous flaps (16.8%). Surgical approaches included free flaps (47.6%) and local flaps (52.5%). Class III obese patients were significantly more likely to be nonambulatory than nonobese patients (OR: 4.10, 95% CI 1.10-15.2, p = 0.035). At final follow-up, 30.1% of patients with Class III obesity were ambulatory, requiring either wheelchairs (42.3%) or assistance devices (26.9%). There were no significant differences in complication rates based on obesity status (0.704). The average follow-up time for the entire cohort was 5.8 years. BMI is critical for patient care and surgical decision-making in LE reconstruction. Further research is warranted to optimize outcomes for higher BMI patients, thereby potentially reducing the burden of postoperative complications and enhancing overall patient recovery.

Stanton EW ，Manasyan A ，Boudiab E ，Carey JN ，Daar DA ... -  《-》

Venous bypass grafts versus arteriovenous loops as recipient vessels for microvascular anastomosis in lower extremity reconstructions: A matched-pair analysis.

Limb salvage in patients with peripheral vascular disease (PVD) and soft tissue defects often requires both a restoration of blood flow to the lower extremity and soft tissue coverage. Outcomes of free tissue transfer may be affected by vein grafts, which can be used for the placement of an autologous venous bypass or an arteriovenous (AV) loop leading to different hemodynamic situations. The purpose of this study was to investigate whether free flap anastomosis to a bypass or an AV loop can be performed with comparable results. We performed a matched-pair analysis of 22 patients with PVD undergoing free flap reconstructions of the lower extremity with end-to-side anastomosis to an autologous venous bypass (n = 11, 1 female and 10 male patients) or an AV loop (n = 11, 2 female and 9 male patients). Defects caused by trauma, infection, ulcer, or fasciotomy were reconstructed in each group with 5 muscle-based flaps, 3 parascapular flaps, 2 anterolateral thigh (ALT) flaps, and 1 conjoined latissimus dorsi and parascapular flap. Postoperative complications including thromboses, flap failures, wound complications, and hematomas were compared. Postoperative complication rates including 1 venous pedicle thrombosis (9%vs. 0%, P = 1.0), minor (18% vs. 9%, P = 1.0) and major wound complications (45% vs. 27%, P = .69) as well as hematomas (27% vs. 36%, P = 1.0) did not show relevant differences between the groups. Flap failures were absent in both groups. In patients with PVD, autologous venous bypass grafts may be used for end-to-side anastomoses of free flaps, with postoperative outcomes being comparable to AV loop reconstructions.

Henn D ，Bigdeli AK ，Horsch M ，Weiß C ，Kühner C ，Hirche C ，Schmidt VJ ，Kneser U ... -  《-》

Larger free flap size is associated with increased complications in lower extremity trauma reconstruction.

Free flap reconstruction after lower extremity trauma remains challenging with various factors affecting overall success. Increasing defect and flap size have been demonstrated to be a surrogate for overall injury severity and correlated with complications. In addition, larger free flaps that encompass more tissue theoretically possess high metabolic demand, and may be more susceptible to ischemic insult. Therefore, the purpose of our study was to determine how flap size affects microsurgical outcomes in the setting of lower extremity trauma reconstruction. Retrospective review of 806 lower extremity free flap reconstructions performed from 1979 to 2016 among three affiliated hospitals: a private university hospital, Veterans Health Administration Hospital (VA), and a large, public hospital serving as a level 1 trauma center for the city. Soft tissue free flaps used for below the knee reconstructions of traumatic injuries were included. A receiver operating curve (ROC) was generated and Youden index was used to determine the optimal flap size for predicting flap success. Based on this, flaps were divided into those smaller than 250 cm2 and larger than 250 cm2 . Partial flap failure, total flap failure, takebacks, and overall major complications (defined as events involving flap compromise) were compared between these two groups. Multivariate logistic regression was performed to determine whether flap size independently predicts complications and flap failures, controlling for injury-related and operative factors. A total of 393 patients underwent lower extremity free tissue transfer. There were 229 flaps (58.2%) with size <250 cm2 and 164 flaps (41.7%) ≥ 250 cm2 . ROC analysis and Youden index calculation demonstrated 250 cm2 (AUC 0.651) to be the cutoff free flap for predicting increasing flap failure. Compared to flaps with less than 250 cm2 , larger flaps were associated with increased major complications (33.6% vs. 50.0%, p = .001), any flap failure (11.8% vs. 25.0%, p = .001) and partial flap failure (4.8% vs. 14.6%, p = .001). Logistic regression analysis controlling for age, flap type, era of reconstruction, number of venous anastomoses, presence of associated injuries, presence of a bone gap, vessel runoff, and flap size identified increasing flap size to be independently predictive of major complications (p = .05), any flap failure (p = .001), partial flap failure (p < .001), and takebacks (p = .03). Subset analysis by flap type demonstrated that when flap size exceeded 250 cm2 , use of muscle flaps was associated with significantly increased flap failure rates (p = .008) while for smaller flap size, there was no significant difference in complications between muscle and fasciocutaneous flaps. Increasing flap size is independently predictive of flap complications. In particular, a flap size cutoff value of 250 cm2 was associated with significantly increased flap failure and complications particularly among muscle-based flaps. Therefore, we suggest that fasciocutaneous flaps be utilized for injuries requiring large surface area of soft tissue reconstruction.

Lee ZH ，Abdou SA ，Ramly EP ，Daar DA ，Stranix JT ，Anzai L ，Saadeh PB ，Levine JP ，Thanik VD ... -  《-》