Role, Management, and Outcome of Free Flap Reconstruction for Acute Full-Thickness Burns in Hands

Pedicled and Free Flap Lower Extremity Reconstruction in Acute Burn Injuries

BACKGROUND

A paucity of studies investigates the outcomes of flap reconstruction in lower extremity acute burns. The aim of this study is to report outcomes of lower extremity acute burn requiring pedicled or free flap coverage.

METHODS

A retrospective cohort study was conducted to compare the outcomes of patients undergone pedicled versus free flap reconstruction of acute lower extremity burns, between August 2010 and December 2022. Collected data included demographics, injury and flap characteristics, complications, and reoperations. χ2 tests were used to measure differences in complication rates between pedicled and free flaps.

RESULTS

A total of 28 patients were involved in the study. Among them, 17 patients underwent 28 pedicled flap procedures, while 11 patients received a single free flap surgery each. In the free flap group, the overall complication rate was 54.5%. In the pedicled flap group, the overall complication rate was 25.0%. Free flaps showed a significantly higher rate of total flap loss compared to pedicled flaps (18.2% vs 0%, P = 0.021). Other differences were not statistically significant.

CONCLUSIONS

Flap coverage in lower extremity acute burns is rarely employed. Yet, in case of critical structures exposure it is often necessary. However, it is important to be aware of the high risk of complications, especially for more complex reconstructions requiring free tissue transfer.

Negative pressure wound therapy in burns: a prospective, randomized-controlled trial

BACKGROUND

Negative-pressure-wound-therapy (NPWT) has become a widely used tool for the coverage and active treatment of complex wounds, including burns. This study aimed to evaluate the effectiveness of NPWT in acute burns of upper and lower extremities and to compare results to the standard-of-care (SOC) at our institution.

METHODS

Patients that were admitted to our institution between May 2019 and November 2021 with burns on extremities between 0.5 % and 10 % of the total body surface area (%TBSA) were included and randomized to either NPWT or SOC (polyhexanide gel, fatty gauze, and cotton wool). Treatment was performed until complete wound healing. Patients that required skin grafts, received additional NPWT after grafting independent on the initial group allocation.

RESULTS

Sixty-five patients suffering from burn injury between May 2019 and November 2021 were randomized into treatment with NPWT (n = 33) or SOC (n = 32); of these, 33 patients (NPWT) and 28 patients (SOC) had complete data sets and were included in the analysis. Both groups were similar regarding age (39.8 ± 13.7 vs. 44.8 ± 16.2 years,p = 0.192), total burn size (3.1 ± 2.3 vs. 3.4 ± 2.8 %TBSA,p = 0.721) and treated wound size (1.9 ± 1.2 vs. 1.5 ± 0.8 %TBSA,p = 0.138). We found no differences regarding healing time (11.0 ± 4.9 vs. 8.6 ± 3.8,p = 0.074, and significant differences in a number of dressing changes throughout the study (2.4 ± 1.5 vs 4.2 ± 1.9,p < 0.001). The Kaplan-Meier time-to-event analysis exhibited no statistically significant difference in the time to healing or skin grafting (p = 0.085) in NPWT group compared with SOC group. The median time to healing or skin grafting was 10(8-11) days for NPWT and 9(7-11) days for SOC. The hazard ratio for healing or skin graft was HR= 0.64(0.38-1.08). The results of the time-to-event analysis as well as the Kaplan-Meier curve on the PPS confirmed this result. We found no differences in secondary surgical operations 15.2 vs 21.4 % pain or functional outcomes.

CONCLUSIONS

In this study, we found no significant difference between the two groups in terms of time to detect wound healing. We also found no difference regarding further operations for wound closure, pain and/or scarring. However, dressing changes were significantly less frequent for patients that were treated with NPWT, which may be a psychological and logistical advantage.

Impact of Microsurgical Reconstruction Timing on the Risk of Free Flap Loss in Acute Burns: Systematic Review and Meta-Analysis

Background

Free tissue transfer is usually considered as a last resort in severe burn cases, when skin substitutes and local flaps are not viable options. Prior studies have demonstrated a free flap loss rate ranging from 0% to 44%. The aim of this study is to identify the ideal timing to perform free flap reconstruction in acute burn-related injuries to minimize free flap loss.

Methods

A systematic review and meta-analysis was performed and reported according to PRISMA guidelines. PubMed, Embase, Web of Science, and Cochrane Library databases were queried. The review protocol was registered on PROSPERO database (CRD42023404478). Three time intervals from day of injury were identified: (1) 0-4 days, (2) 5-21 days, and (3) 22 days-6 weeks. The primary outcome was total free flap loss.

Results

A total of 17 articles met inclusion criteria. The analysis included 275 free flaps performed in 260 patients (88% men, 12% women) affected by acute burn injuries. The pooled prevalence of free flap failure in the three time intervals (0-4 days, 5-21 days, and 22 days-6 weeks) were 7.32% [95% confidence interval (CI): 2.38%-20.37%], 16.55% (95% CI: 11.35%-23.51%), and 6.74% (95% CI: 3.06%-14.20%), respectively.

Conclusions

Free flap reconstruction carries a high risk of failure in patients with acute burn. However, timing of the reconstruction appears to influence surgical outcomes. Free flap reconstruction performed between 5 and 21 days from burn injury had a trend toward higher flap loss rates and should be discouraged.

NovoSorb® Biodegradable Temporising Matrix (BTM): What we learned from the first 300 consecutive cases

INTRODUCTION

Extensive full-thickness soft-tissue defects remain a challenge in reconstructive surgery. NovoSorb® Biodegradable Temporising Matrix (BTM) represents a novel dermal substitute and was evaluated in wounds deriving from different aetiologies and to highlight risk factors for poor take rates.

METHODS

All patients treated with BTM at our department between March 2020 and October 2022 were included. Differences in univariate and linear regression models identified predictors and risk factors for take rates of BTM and split-thickness skin grafts (STSG).

RESULTS

Three hundred patients (mean age 54.2 ± 20.1 years, 66.3% male, 59.7% burns, 19.7% trauma and 20.6% others) were evaluated. Mean take rates of BTM and STSG after BTM delamination were 82.7 ± 25.2% and 86.0 ± 22.6%, respectively. Multiple regression analyses showed that higher body mass index (BMI, OR 0.43, 95% CI 0.86, -0.01, p = 0.44), prior allograft transplantation (OR 15.12, 95% CI 26.98, -3.31, p = 0.041), longer trauma-to-BTM-application intervals (OR 0.01, 95% CI 0.001, -0.001, p = 0.038), positive wound swabs before BTM (OR 7.15, 95% CI 13.50, -0.80, p = 0.028) and peripheral artery disease (OR 10.80, 95% CI 18.63, -2.96, p = 0.007) were associated with poorer BTM take. Higher BMI (OR 0.40, 95% CI 0.76, -0.08, p = 0.026), increasing BTM graft surface areas (OR 0.58, 95% CI -1.00, -0.17, p = 0.005), prior allograft (OR 12.20, 95% CI -21.99, -2.41, p = 0.015) or autograft transplantations (OR 22.42, 95% CI 38.69, -6.14, p = 0.001), tumour as the aetiology of the wound (OR 37.42, 95% CI 57.41, -17.83, p = 0.001), diabetes (OR 6.64, 95% CI 12.80, -0.48, p = 0.035) and impaired kidney function (OR 5.90, 95% CI 10.94, -0.86, p = 0.021) were associated with poorer STSG take after delamination of BTM, whereas higher BTM take rates were associated with better STSG take (OR 0.40, 95% CI 0.31,0.50, p < 0.001).

CONCLUSION

Extensive complex wounds of different aetiologies unsuitable for immediate STSG can be successfully reconstructed by means of two-staged BTM application and subsequent skin grafting. Importantly, presence of wound contamination or infection and prior allograft coverage appear to jeopardise good BTM and STSG take.

Use of the modified meek technique for the coverage of extensive burn wounds

INTRODUCTION

Autologous split thickness skin grafting using meshing technique remains the preferred option for the management of deep dermal and full thickness burns. The limited donor site availability seen in patients with extensive burns, however, restricts use of the mesh grafting technique for skin expansion. Meek micrografting was developed to allow for greater expansion, and, therefore, more reliable treatment of extensive burns. This study aimed to present our outcomes using the Meek micrografting technique and identify risk factors for graft failure.

METHODS

A retrospective review of patients admitted to our large academic hospital who were treated with the Meek micrografting technique from 2013 to 2022 was conducted. Patient demographics, surgical characteristics and outcomes were reported. Regression analyses were performed to identify factors that influence graft take and reoperation rate.

RESULTS

A total of 73 patients with a mean age of 45.7 ± 19.9 years and mean burn size of 60.0 ± 17.8%TBSA, with 45.3 ± 14.9% TBSA being third degree burns, received Meek transplantation. The mean graft take after removal of the pre-folded polyamide gauze at the tenth post-operative day was 75.8 ± 14.7%. Pre-treatment with use of an allograft, longer waiting time between admission and Meek grafting and transplantation over a dermal matrix were identified as positive predictors for graft take, while age was established as a negative predictor.

CONCLUSION

By examining the outcomes of the Meek micrografting technique in extensive burn wounds we identified that preconditioning of the wound bed, through allograft or negative pressure wound therapy application, positively correlates with improved outcomes, including higher graft take. At the same time, older age was seen to negatively correlate with graft take. Overall, Meek transplantation displays a favorable safety profile with promising outcomes. Future prospective studies and clinical trials can optimize the procedure and help establish it as the golden standard for extensive and complex burns.

Intraoperative Heparin Bolus and Postoperative Anticoagulation with Low Molecular Weight Heparin Increase Reliability of Microsurgical Free Flaps for Upper Extremity Reconstruction

BACKGROUND

 Microsurgery is an indispensable tool of upper extremity reconstruction addressing defect coverage and the restoration of function. Perioperative anticoagulation and antiplatelet therapy are controversially discussed with impact on microsurgical outcome, but without clear evidence. This study aims to evaluate the impact of perioperative anticoagulation and antiplatelet therapy in microsurgical upper extremity reconstruction.

METHODS

 All eligible patients treated with microsurgical upper extremity reconstruction between January 2000 and July 2014 were included in a comparative analysis to define a superior anticoagulation and antiplatelet regime in a retrospective study. Endpoints were all major complications (e.g., total flap loss, arterial and venous thrombosis) as well as minor complication.

RESULTS

 A total of 183 eligible free flaps to the upper extremity were transferred in 169 patients. Altogether, 11 arterial (6.0%) and 9 venous (4.9%) thromboses, 11 total flap losses (6.0%), and 16 cases with hematoma (8.7%) were detected. In the subgroup analysis, patients who did not receive any heparin intraoperatively (n = 21; 11.5%) had a higher rate of major complications (p = 0.001), with total flap loss being the most frequent event (p = 0.004). A trend was shown for intraoperative bolus administration of 501 to 1,000 units unfractionated heparin (UFH) intravenously to have the lowest rate of major complications (p = 0.058). Intraoperative administration of acetylsalicylic acid (n = 13; 8.1%) did not have any influence on the rate of major complications. Postoperative anticoagulation with continuous UFH intravenously (n = 68; 37.2%) resulted in more frequent complications (p = 0.012), for example, an increased rate of total flap loss (p = 0.02) and arterial thrombosis (p = 0.02).

CONCLUSION

 The results of the present study favor administration of 501 to 1,000 units UFH intravenously as an intraoperative bolus (e.g., 750 units UFH intravenously). Postoperative low molecular weight heparin subcutaneous application in a prophylactic dose given once or twice a day was associated with less complications compared with continuous infusion of UFH, although continuously applied UFH may reflect an increased risk profile.

Implementation and Validation of Free Flaps in Acute and Reconstructive Burn Care

Microsurgical free flap reconstruction in acute burn care offers the option of reconstructing even challenging defects in a single stage procedure. Due to altered rheological and hemodynamic conditions in severely burned patients, it bears the risk of a higher complication rate compared to microsurgical reconstruction in other patients. To avoid failure, appropriate indications for free flap reconstruction should be reviewed thoroughly. Several aspects concerning timing of the procedure, individual flap choice, selection and preparation of the recipient vessels, and perioperative measures must be considered. Respecting these specific conditions, a low complication rate, comparable to those seen in microsurgical reconstruction of other traumatic limb defects, can be observed. Hence, the free flap procedure in acute burn care is a relatively safe and reliable tool in the armamentarium of acute burn surgery. In reconstructive burn care, microsurgical tissue transfer is routinely used to treat scar contractures. Due to the more robust perioperative condition of patients, even lower rates of complication are seen in microsurgical reconstruction.