Blood Perfusion of the Free Anterolateral Thigh Perforator Flap: Its Beneficial Effect in the Reconstruction of Infected Wounds in the Lower Extremity

Multidisciplinary management of the bone and joint infection complicating treatment of an open fracture of the lower limb

Bone and joint infections (BJI) of the lower limb can cause functional sequelae and in some cases have an impact on patient's life prognostic. One of the main objectives of multidisciplinary consultation team meetings (MTM) in the treatment of bone and joint infections is to provide an appropriate medical-surgical care, pooling skills of different organ specialists: infectious disease physicians, microbiologists, orthopedic surgeons and plastic surgeons. Treatment is based on aggressive debridement, bone stabilization, adequate antibiotic therapy, long-term coverage of the loss of skin substance and close clinical monitoring. The authors present their multidisciplinary diagnostic and therapeutic approaches to BJI complicating an open fracture at a referent center in the management of complex bone and joint infections.

Correlation between blood flow, tissue volume and microvessel density in the flap

The purpose of this study was to assess the correlation between tissue volume and blood flow of the flap in an animal model. Using animal model, tissue volume can be attenuated, and precise change of blood flow could be evaluated. We further investigate the relationship between blood flow and vascular density in the tissue. In this study, we assessed flap conductance (ml/min/mm Hg) as to evaluate the conductivity of blood flow into the flap. Japanese white rabbit was used (n = 7) for this study. The amount of blood flow of jejunal and latissimus dorsi muscle (LD) flaps was measured while removing the distal portion of the flap sequentially. Conductance at each time was calculated from blood pressure and blood flow volume. The tissue volume at each time was also measured. The correlation between conductance and volume was analyzed using a linear mixed model. Immunohistochemical evaluation of microvessel densities (MVD) in these tissues was also performed for CD31/PECAM1 positive area. Conductance and tissue volume were significantly correlated in both jejunal and LD flaps. As the volume increases by 1 cm³, the conductance increased significantly by 0.012 ml/min/mm Hg in jejunum, and by 0.0047 ml/min/mm Hg in LD. Mean MVD was 1.15 ± 0.52% in the jejunum and 0.37 ± 0.29% in the LD muscle. In this study, we revealed that flap conductance is proportional to volume and proportional constant is different between the type of tissue. It suggests that the difference of MVD creates the unique conductance of each tissue.

A comparison of the bipedicled nerve flap with the Littler flap for reconstructing a neurocutaneous defect of digits

BACKGROUND

Complex digital injuries involving soft-tissue loss and digital nerve defect continues to pose a reconstructive challenge. This study reports the repair of such neurocutaneous defect with the bipedicled nerve flap or the Littler flap and compares the results of the two techniques.

METHODS

A retrospective study was conducted in 59 patients who had a neurocutaneous defect in the single digit treated with the bipedicled nerve flap or the Littler flap from Jul 2008 to May 2016. The patients were divided into two groups based on which flap was chosen. At the final follow-up, the two groups were compared for static two-point discrimination and Semmes-Weinstein monofilament scores on both flap and pulp, and pain, cold intolerance and patient satisfaction of the reconstructed digit.

RESULTS

Significant differences were found in static two-point discrimination, pain, cold intolerance, and patient satisfaction (p < 0.05). In comparison with the bipedicled flap group, the Littler flap group presented better discriminatory sensation in the flap and pulp, but exhibited higher incidence of pain and cold intolerance in the reconstructed digit. In the donor digits, the bipedicled flap group achieved lower pain incidence. Finally, the bipedicled flap group attained a larger degree of satisfaction than the Littler flap group.

CONCLUSIONS

When reconstructing a complex neurocutaneous defect in the digit, choosing the bipedicled nerve flap rather than the Littler flap attains lower incidence of pain and cold intolerance, and higher patient satisfaction. Our results suggest that repair of the transected digital nerves can reduce neuroma incidence.

Distally based anterolateral thigh flap: an underutilized option for peri-patellar wound coverage

Wound coverage in the supra-patellar area presents a significant challenge for orthopaedic and reconstructive surgeons due to the need for preservation of knee joint function but the paucity of regional soft tissue flaps available. While many orthopaedic and reconstructive surgeons make use of the rotational gastrocnemius flap for coverage of peri-patellar defects, this flap has certain limitations. The goal of this study was to report a single-centre experience with the use of the distally based anterolateral thigh flap (ALT) and review the current literature on the use of the ALT for peri-patellar defects. In this report, both a single-centre experience using distally based anterolateral thigh (ALT) island flaps for supra-patellar wound coverage and the existing literature on this topic were reviewed. A systematic literature review was performed to assess the use of the ALT for peri-patellar wounds. Five patients with a mean age of 69 underwent a distally based ALT flap for coverage of peri-patellar defects. Four out of 5 flaps survived at the end of their respective follow-up. Based on this combined experience, the distally based reverse-flow anterolateral thigh island flap represents a useful but relatively underutilized option for appropriately selected supra-patellar wounds due to minimal donor site morbidity, multiple flap components, and predictable pedicle anatomy. The flap’s major weakness is its potentially unreliable venous drainage, requiring delay or secondary venous outflow anastomosis. Given the ALT flap’s favourable profile, the authors recommend consideration for its use when managing a peri-patellar coverage wound issue.

Free Flap Monitoring Using Near-Infrared Spectroscopy: A Systemic Review

BACKGROUND

Although free flaps have become a reliable technique, vascular occlusion remains a significant risk. Flap survival is closely linked to the time interval between the onset and surgical repair of a microvascular problem. The newly emerged near-infrared spectroscopy (NIRS) shows the characteristics of being noninvasive, continuous, easy to use, objective, and immediately reflective, possibly making it an ideal candidate for postoperative flap monitoring.

METHODS

A systemic review was conducted to determine the clinical value of NIRS in the early detection of vascular crisis associated with a free flap. A literature search was conducted using PubMed (MEDLINE), the Cochrane Library, and Web of Science from database inception through October 2013. Studies were selected strictly according to the inclusion/exclusion criteria by 2 independent reviews.

RESULTS

Eight studies were finally included in this review. A total of 710 free flap procedures were performed in 629 patients using NIRS for monitoring. At the same time, 433 free flaps performed in 430 patients without the use of NIRS were included as the control group. No significant differences in the rates of vascular crisis (P = 0.917) and re-exploration (P = 0.187). However, there were significant differences in the salvage rates (P < 0.001) and flap failure rates (P = 0.003). For the free flaps monitored by NIRS that were not associated with vascular crisis, no alarms were raised by NIRS, giving 100% sensitivity and specificity.

CONCLUSION

Near-infrared spectroscopy seems to be a highly suitable candidate for postoperative flap monitoring. Larger-scale, randomized, multicentric clinical trials are needed in the future.

Noncontact diffuse optical assessment of blood flow changes in head and neck free tissue transfer flaps

Knowledge of tissue blood flow (BF) changes after free tissue transfer may enable surgeons to predict the failure of flap thrombosis at an early stage. This study used our recently developed noncontact diffuse correlation spectroscopy to monitor dynamic BF changes in free flaps without getting in contact with the targeted tissue. Eight free flaps were elevated in patients with head and neck cancer; one of the flaps failed. Multiple BF measurements probing the transferred tissue were performed during and post the surgical operation. Postoperative BF values were normalized to the intraoperative baselines (assigning "1") for the calculation of relative BF change (rBF). The rBF changes over the seven successful flaps were 1.89 ± 0.15, 2.26 ± 0.13, and 2.43 ± 0.13 (mean ± standard error), respectively, on postoperative days 2, 4, and 7. These postoperative values were significantly higher than the intraoperative baseline values (p<0.001), indicating a gradual recovery of flap vascularity after the tissue transfer. By contrast, rBF changes observed from the unsuccessful flaps were 1.14 and 1.34, respectively, on postoperative days 2 and 4, indicating less flow recovery. Measurement of BF recovery after flap anastomosis holds the potential to act early to salvage ischemic flaps.

Use of a bipedicled nerve flap taken from the dorsum of the digit for reconstruction of neurocutaneous defect in the adjacent finger

A digital nerve defect complicated by an associated soft-tissue loss poses a reconstructive challenge. This article reports reconstruction of a similar complex injury using a bipedicled nerve flap including a nerve graft from the dorsal branch of the digital nerve. From July 2008 to May 2010, a retrospective study was conducted with nine consecutive patients who had a combination of soft tissue and digital nerve defects. The injured fingers requiring reconstruction included three index, four middle and two ring fingers. The mean size of the soft-tissue losses was 2.8×2.1 cm. The flap is supplied by the digital artery and the venous drainage is by means of a dorsal vein. The mean flap size was 3.1×2.3 cm. The nerve gaps were bridged with the nerve graft attached with the flap. The average length of the nerve grafts was 3.0 cm. All flaps survived completely, and the defects were reconstructed successfully. Venous congestion was not observed in our series. At a mean follow-up period of 23 months, the average scores of static two-point discrimination (2PD) and Semmes-Weinstein monofilament on the finger pulp of the injured side were 7.5 mm and 3.93, respectively. The donor site morbidity was acceptable. According to the Michigan Hand Outcomes Questionnaire, four patients were strongly satisfied and five were satisfied with functional recovery of the injured finger. The bipedicled nerve flap is a safe and effective option for reconstruction of complex digital injury involving soft tissue and nerve defects. Our technique has been shown to provide sufficient sensory recovery. ClinicalTrials.gov ID: NCT01707654.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Customized reconstruction with the free anterolateral thigh perforator flap

From April of 2003 through September of 2006, 70 free anterolateral thigh (ALT) flaps were transferred for reconstructing soft-tissue defects. The overall success rate was 96%. Among 70 free ALT flaps, 11 were elevated as cutaneous ALT septocutaneous vessel flaps. Fifty-seven were harvested as cutaneous ALT myocutaneous "true" perforator flaps. Two flaps were used as fasciocutaneous perforator flaps based on independent skin vessels. Fifty-four ALT flaps were used for lower extremity reconstruction, 11 flaps were used for upper extremity reconstruction, 3 flaps were used for trunk reconstruction, and 1 flap was used for head and neck reconstruction. Total flap failure occurred in 3 patients (4.28% of the flaps), and partial failure occurred in 5 patients (7.14% of the flaps). The three flaps that failed completely were reconstructed with a free radial forearm flap, a latissimus dorsi flap and skin grafting, respectively. Among the five flaps that failed partially, three were reconstructed with skin grafting, one with a sural flap, and one with primary closure. The free ALT flap has become the workhorse for covering defects in most clinical situations in our center. It is a reliable flap with consistent anatomy and a long, constant pedicle diameter. Its versatility, in which thickness and volume can be adjusted, leads to a perfect match for customized reconstruction of complex defects.

The use of integra artificial dermis to minimize donor-site morbidity after suprafascial dissection of the radial forearm flap

In an effort to minimize the radial forearm flap donor-site morbidity, the flap was elevated using the suprafascial dissection technique, in six patients with various facial defects. The donor site was covered primarily with Integra artificial skin and secondarily with an ultrathin split-thickness skin graft. The mean time to wound healing of the forearm donor site was 24 days. There were no flap failures, and all flaps healed uneventfully. At the end of the follow-up, all patients showed normal range of motion of the wrist and the fingers, normal power grip, and power pinch. All patients evaluated the esthetic appearance of the forearm donor site as very good. In conclusion, suprafascial dissection of the forearm flap creates a superior graft recipient site, and the use of Integra artificial dermis is a valuable advancement to further minimize the donor-site morbidity, resulting in excellent functional and aesthetic outcomes.