Salvage of free flaps after venous thrombosis: Case report

The Use of Fibrinolytic Agents in the Salvage of Free Flaps: A Systematic Review

BACKGROUND

Microvascular thrombosis following free tissue transfer presents a complex challenge for surgeons and carries the potential risk of flap failure. The application of fibrinolytic agents represents a robust therapeutic option. The aim of this systematic review is to provide a comprehensive overview of the clinical use of fibrinolytic drugs in the rescue of compromised free flaps.

METHODS

A systematic literature search for clinical studies detailing the utilization of fibrinolytic agents for salvaging free flaps was conducted using the PubMed and Web of Science databases. The inclusion criteria encompassed English-language publications that specifically addressed the clinical application of fibrinolytic agents for free-flap salvage.

RESULTS

A total of 331 articles were screened after excluding duplicates, with 56 meeting the inclusion criteria. Among these, 21 were clinical trials (evidence level III), and 35 were case studies (evidence level IV/V). In total, 459 flaps underwent treatment with fibrinolytic agents.

CONCLUSION

The application of fibrinolytic agents appears to be a valuable intervention for rescuing compromised free flaps attributable to microvascular compromise. Notably, no prospective randomized trials have been published on this subject, and the evidence within the existing literature is characterized by its limited and heterogeneous nature. Further research is imperative to gather data on the efficacy, dosage, and safety profile of fibrinolytic agents.

How do i salvage that flap?; An evidence-based primer on salvage techniques for head & neck microvascular free flaps

Interventional strategies for dealing with microvascular free flap failure are varied among institutions and even individual surgeons. This systematic review aims to identify the published methods for salvaging a failing free flap and provide surgeons with a comprehensive toolset for successful intervention. A title and abstract search of the PubMed, Embase, and Web of Science databases was performed. 1694 abstracts were screened by three reviewers according to Prisma guidelines. 62 full text articles meeting inclusion criteria detailed techniques which were separated into the categories of thrombectomy, thrombolysis, leech therapy, vascular fistula, and an "other" category outlining techniques which did not fit into the prior framework. Assessment of the efficacy of individual salvage techniques is limited due to limited empirical data, however, the approach to successful salvage should be based on timely identification of flap compromise, followed by the implementation of one or several of the aforementioned techniques.

Primary thrombolysis for free flap surgery in head and neck reconstruction: a case report and review

The use of free flaps is an essential and reliable method of reconstruction in complex head and neck defects. Flap failure remains the most feared complication, the most common cause being pedicle thrombosis. Among other measures, thrombolysis is useful when manual thrombectomy has failed to restore flap perfusion, in the setting of late or established thrombosis, or in arterial thrombosis with distal clot propagation. We report a case of pedicle arterial thrombosis with distal clot propagation which occurred during reconstruction of a maxillectomy defect, and was successfully treated with thrombolysis using recombinant tissue plasminogen activator. We also review the literature regarding the use of thrombolysis in free flap surgery, and propose an algorithm for the salvage of free flaps in head and neck reconstruction.

Pharmacological thrombolysis: the last choice for salvaging free flaps

Microvascular free flap transfer has become a prevailing surgery with a failure rate of <5%. However, pedicle thrombosis occurs more frequently than indicated by the failure rate. This difference is due to the successful salvage of failing flaps. During exploration, thrombi are often encountered at anastomotic sites, whereas these causes could not explain vascular compromise in other patients. Thus, we hypothesized that thrombogenic processes might occur at remote sites, specifically within microvessels of the transferred flap. This study retrospectively evaluated 323 patients who underwent microvascular free flap transfer between March 2012 and October 2016 at Korea University Guro Hospital. All patients requiring emergency exploration within 7 days after surgery were retrospectively reviewed. Of patients, 15 required explorative surgery for suspected circulatory compromise. Eight were diagnosed with thrombosis at the perianastomotic site and salvaged in accordance with our protocol. There was no detectable thrombosis at the anastomotic site in seven patients, including one patient in whom thrombosis resolved with topical papaverine application and heparinization. The remaining six patients were diagnosed with intra-flap microthrombosis without discernable thrombosis at the anastomotic site. All patients were treated following our urokinase administration protocol and salvaged without complications. Possible external causes should first be evaluated when salvaging free flaps; in the absence of such evidence, urokinase administration may be utilized as a last resort. This study is the first report describing the effectiveness of pharmacological thrombolysis in resolving intra-flap microthrombosis. Furthermore, a safe and efficient urokinase administration protocol is suggested for perianastomotic thrombosis and intra-flap microthrombosis.

Dichloroacetate Reduces Tissue Necrosis in a Rat Transverse Rectus Abdominis Musculocutaneous Flap Model

OBJECTIVE

Ischemia-related complications may occur during postmastectomy transverse rectus abdominis musculocutaneous (TRAM) flap reconstruction. The aim of our study was to investigate whether necrosis of susceptible flap regions could be reduced by dichloroacetate (DCA)-induced stimulation of oxidative metabolism in hypoxic tissue.

METHODS

The study was a randomized control trial using male Sprague-Dawley rats. A pedicled TRAM flap based upon the right inferior epigastric artery was elevated and reapproximated. Animals were randomly assigned to 1 of 5 treatment groups (n = 6). Group I received no DCA; groups II through V were administered 75 mg/kg DCA orally 24 hours preoperative; in addition, groups II through IV received 75 mg/kg/d DCA orally postoperative for 4 days; group III also received 75 mg/kg DCA (IP) intraoperatively; groups IV and V were given 15 mg/kg/d DCA orally for 6 days before the 24-hour preoperative treatment. Four days postsurgery, skin paddles were photographed and assessed for viability. Underlying TRAM muscle was biopsied for histologic analysis. Blood lactate levels were measured at pre- and postoperative time points. The mean percentages of viable skin paddle were as follows: 32.0%+/- 4.0% (group I), 68.1% +/- 6.2% (group II), 84.3% +/- 5.9% (group III), 92.8% +/- 2.0% (group IV), 82.6% +/- 5.8% (group V).

RESULTS

Statistically significant differences were found in all experimental (DCA) groups relative to the controls (P < 0.01). Group IV (6-day DCA preconditioning, plus 24-hour preoperative and 4-day postoperative treatment) displayed the greatest improvement in flap viability, significantly better than other DCA groups (P < 0.01). Group IV also had significantly lower serum lactate levels than controls (P < 0.05). Histologic examination of muscle biopsies revealed reductions in inflammation and necrosis correlating with DCA treatment and skin paddle survival.

CONCLUSIONS

This study indicates that DCA may provide a useful pharmacologic tool for reducing ischemia-related necrosis in TRAM flaps.

Venous congestive flap salvage with subcutaneous rtPA

Free-flap success has been the rule with technical advancements in microsurgery. Despite improvements, thrombosis and flap loss still occur occasionally. Salvaging a sick flap can be a harrowing experience, even in the most experienced hands. Thrombolysis using intravenous and intra-arterial urokinase, streptokinase, and/or tissue plasminogen activator (rtPA) administered through the flap vascular pedicle has been reported in free-flap salvages. In such situations, success depends on early diagnosis and emergent exploration. Recently, we successfully used rtPA subcutaneously to salvage a venous congested free transverse rectus abdominus myocutaneous (TRAM) flap. Here, we report on that case.

Pharmacological thrombolysis: One more weapon for free-flap salvage

Despite the high success rate of free-tissue transfer, thrombosis still complicates 5-30% of cases. Meticoulous technique, careful vessel selection, and pharmacological prophylaxis are not always enough to avoid thrombosis. Early diagnosis and reintervention provide the only way to salvage a thrombosed free flap, in case of either arterial or venous thrombosis. When kinking, torsion, or external compression of the pedicle are ruled out, and thrombectomy and redo of the anastomosis are unsuccessful, the last resort to save the flap is thrombolytic therapy. The authors present their experience with the salvage of two otherwise lost flaps by means of urokinase thrombolysis through direct intra-arterial injection with the vein left open to avoid systemic diffusion of the drug, and give technical tips to improve drug delivery to the flap. Pharmacological thrombolysis is an additional and effective weapon to resolve thrombosis, if properly used, to be considered by every reconstructive microsurgeon.