Current concepts in salvage procedures for failing microvascular flaps: is there a superior technique? Insights from a systematic review of the literature

Use of perfusion device for free flap salvage after ischemia in swine

INTRODUCTION

In free flap reconstruction, improving flap tolerance to warm ischemia (WI) is fundamental. WI is the result of a venous or arterial thrombosis, which can only be addressed through surgical revision. No additional treatments have shown superior efficacy at salvaging free flaps after or during WI. Custom perfusion machines (PM), used to reduce the intensity of lesions of the flap stored in cold ischemia, have not been evaluated for WI flap salvage. This proof-of-concept study assessed whether the Lifeport® perfusion machine could improve the salvage procedure's success rates after one hour of venous WI.

METHODS

Five different groups were evaluated with four porcine latissimus dorsi free flaps included in each group. Depending on the group, the flaps were subjected to one hour of WI followed by revascularization, static hypothermic submersion, or dynamic Lifeport® perfusion. Additionally, two flap perfusion liquids were evaluated: KPS-1® and IGL-1®. Biopsies were performed before in vivo warm ischemia of the flap, after in vivo warm ischemia of the flap, and after one and two hours of preservation. Interstitial edema, muscular cell size and muscular diffuse necrosis were quantified by histological assessment.

RESULTS

Static submersion did not demonstrate any efficacy for venous flap salvage. Dynamic perfusion on Lifeport® machine showed a significant improvement in tissue parameters. Thrombi and fibrine, present during the WI period, were no longer visible inside vessels and the perfusion machine flow evacuated the inflammatory cells and their substrates from the flap. The flap weights did not increase during perfusion time, confirming the benefits of the Lifeport® perfusion machine.

CONCLUSION

Evaluating Lifeport® advantages on human free flap salvage is necessary to confirm the benefits for the tissue and to increase post-operative results after congestive free flap revision surgery.

Safe and effective thrombolysis in free flap salvage: Intra-arterial urokinase infusion

Despite the high success rate in reconstruction using free tissue transfer, flap failure is often caused by microvascular thrombosis. In a small percentage of cases with complete flap loss, a salvage procedure is performed. In the present study, the effectiveness of intra-arterial urokinase infusion through the free flap tissue was investigated to develop a protocol to prevent thrombotic failure. The retrospective study evaluated the medical records of patients who underwent salvage procedure with intra-arterial urokinase infusion after reconstruction with free flap transfer between January 2013 and July 2019. Thrombolysis with urokinase infusion was administered as salvage treatment for patients who experienced flap compromise more than 24 hours after free flap surgery. Because of an external venous drainage through the resected vein, 100,000 IU of urokinase was infused into the arterial pedicle only into the flap circulation. A total of 16 patients was included in the present study. The mean time to re-exploration was 45.4 hours (range: 24-88 hours), and the mean quantity of infused urokinase was 69,688 IU (range: 30,000-100,000 IU). 5 cases presented with both arterial and venous thrombosis, while 10 cases had only venous thrombosis and 1 case had only arterial thrombosis; in a study of 16 patients undergoing flap surgery, 11 flaps were found to have survived completely, while 2 flaps experienced transient partial necrosis and 3 were lost despite salvage efforts. In other word, 81.3% (13 of 16) of flaps survived. Systemic complications, including gastrointestinal bleeding, hematemesis, and hemorrhagic stroke, were not observed. The free flap can be effectively and safely salvaged without systemic hemorrhagic complications using high-dose intra-arterial urokinase infusion within a short period of time without systemic circulation, even in delayed salvage cases. Urokinase infusion results in successful salvage and low rate of fat necrosis.

Head and neck free-flap salvage

PURPOSE OF REVIEW

To highlight three clinical arenas in which head and neck free-flap compromise is encountered and acted upon: nonoperative, operative and postoperative realms.

RECENT FINDINGS

Time to identification and intervention is paramount to successful free-flap salvage. Surgical microvascular revision remains chief amongst strategies to revert vascular compromise of a free-flap. Adjuncts, such as thrombolytics and systemic anticoagulation have an important role in the complex work of microvascular free tissue care. Venous congestion of free flaps holds favorable for salvage when compared with arterial insufficiency.

SUMMARY

Vascular compromise of head and neck free flaps is a rare and feared event for microvascular surgeons, with successful transfers rates approaching above 95%. Success in salvage is dependent on prompt identification of tissue compromise and timely, directed interventions to re-establish tissue perfusion.

Negative Pressure Wound Therapy as a Salvage Procedure in Venous Congestion of Microsurgical Procedures

Negative pressure wound therapy (NPWT) is widely used in skin defects, active infection, and surgical reconstruction; lately, it is being used after skin graft to improve the adhesion on the receptor area. During the last decade, another indication has been identified: the use of NPTW to avoid complications after free flaps such as venous congestion and the risk of necrosis. NPWT can be used in the initial complication of a free flap, and the venous congestions can be treated with this technique, with very good outcomes. NPWT can be established as a part of a postoperative protocol in microsurgical procedures to avoid major complications.

Hirudotherapy (medicinal leeches) for treatment of upper airway obstruction in a dog

OBJECTIVE

To describe upper airway obstruction (UAO) in a dog treated with medicinal leeches (hirudotherapy) as an ancillary therapy to hasten recovery.

CASE SUMMARY

A 10-month-old neutered female Mastiff presented for acute respiratory distress. On admission, the dog was tachycardic, cyanotic, and orthopneic; stridor was audible. A 10-cm soft tissue swelling in the right ventral cervical region and bruising around the rostral mandible were noted. At the time of endotracheal intubation, the trachea was deviated to the right as a consequence of severe soft tissue swelling that was contiguous with the sublingual hematoma and cervical region, causing loss of visualization of the arytenoids. A computed tomography with contrast scan of the head, neck, and thorax was performed, showing severe soft tissue swelling of the tongue, obliteration of the common pharyngeal/laryngeal regions from suspected hemorrhage, and rightward displacement of pharynx, larynx, and proximal trachea. Marked diffuse bronchial/bronchiolar thickening associated with bronchiolectasis and diffuse opacification of the pulmonary parenchyma with regions of consolidation were noted. The dog was minimally hypercoagulable on thromboelastography. The imaging results together with results of bronchoalveolar lavage cytology supported a comorbidity of eosinophilic bronchopneumopathy. Intubation was maintained with infusions of propofol and fentanyl, with minimal changes in oropharyngeal swelling within the first 18 hours of treatment. Medicinal leeches were then applied to the sublingual and cervical regions. There was continued slow bleeding from the sites of leech detachment, and the dog was able to be extubated at 44 hours, followed by hospital discharge.

NEW/UNIQUE INFORMATION PROVIDED

Leeches are utilized in human medicine for treatment of UAO. Although UAO from hemorrhage has been described in dogs, this is the first report of medicinal leeches (Hirudo verbana) as complementary treatment for sublingual hematoma that contributed to UAO.

Consensus of free flap complications: Using a nomenclature paradigm in microvascular head and neck reconstruction

BACKGROUND

We aim to define a set of terms for common free flap complications with evidence-based descriptions.

METHODS

Clinical consensus surveys were conducted among a panel of head and neck/reconstructive surgeons (N = 11). A content validity index for relevancy and clarity for each item was computed and adjusted for chance agreement (modified kappa, K). Items with K < 0.74 for relevancy (i.e., ratings of "good" or "fair") were eliminated.

RESULTS

Five out of nineteen terms scored K < 0.74. Eliminated terms included "vascular compromise"; "cellulitis"; "surgical site abscess"; "malocclusion"; and "non- or mal-union." Terms that achieved consensus were "total/partial free flap failure"; "free flap takeback"; "arterial thrombosis"; "venous thrombosis"; "revision of microvascular anastomosis"; "fistula"; "wound dehiscence"; "hematoma"; "seroma"; "partial skin graft failure"; "total skin graft failure"; "exposed hardware or bone"; and "hardware failure."

CONCLUSION

Standardized reporting would encourage multi-institutional research collaboration, larger scale quality improvement initiatives, the ability to set risk-adjusted benchmarks, and enhance education and communication.

Hirudotherapy for neonatal limb ischemia during ECMO support: A word of caution

INTRODUCTION

Disordered coagulation, clot formation and distal limb ischemia are complications of extracorporeal membrane oxygenation (ECMO) with significant morbidity and mortality. Medicinal leech therapy (hirudotherapy) has been attempted in plastic and orthopedic surgeries to improve venous congestion and salvage ischemic flaps. To our knowledge this has not been reported in pediatric cardiac surgery or during ECMO support. We present a complex neonate whose ECMO course was complicated by distal limb ischemia for whom leech therapy was attempted.

PATIENT AND INTERVENTION

A 2-week-old 2.7 kg infant required ECMO support secondary to perioperative multiorgan system dysfunction following repair of critical coarctation and ventricular septal defect. Despite systemic anticoagulation, his clinical course was complicated by arterial thrombus, vasopressor-induced vascular spasm and bilateral distal limb ischemia. Medicinal leech therapy was tried after initially failing conventional measures.

RESULT

Following the third leech application, this patient developed significant hemorrhage from the web space adjacent to the left great toe. An estimated 450 ml of blood loss occurred and more than 300 ml of blood product transfusions were required. He ultimately progressed to irreversible systemic end organ dysfunction and comfort care was provided.

CONCLUSION

The use of medicinal leech therapy in pediatric cardiac surgery may be considered to minimize the consequences of advanced limb ischemia and venous congestion. However, this should be used with caution while patients are systemically anticoagulated during ECMO support. A directed review is presented here to assist in determining optimal application and potential course of therapy.

Successful Salvage of Pedicled Latissimus Dorsi Flap after Venous Thrombosis by Selective Thrombolytic Therapy

While the use of free flaps has become routine and is associated with a low complication rate, pedicled flaps remain a solid reconstructive option in various clinical situations. Pedicled flaps provide a reliable vascular supply and involve a simple surgical procedure. Although the procedure is advantageous from the standpoint of a low rate of flap ischemia, thrombosis, and total flap loss, these complications are still occasionally observed due to intraoperative pedicle injury, postoperative torsion, or compression. Here we report on a case of severe venous thrombosis in a pedicled latissimus dorsi (LD) flap used for breast reconstruction. The patient was a 52-year-old woman who underwent mastectomy and immediate breast reconstruction with a LD flap for left breast cancer. Postoperatively, the color of the skin paddle became dark blue over time. Emergent surgical exploration revealed kinking and narrowing of the thoracodorsal vessels and extensive venous thrombi. The kinked pedicles were repaired and selective thrombolytic therapy was performed. A thrombolytic agent was administered through the serratus anterior branch of the thoracodorsal artery in retrograde fashion while the thoracodorsal vessels were clamped just cephalad to the bifurcation. This allowed for draining of the thrombolytic agent and thrombi through the serratus anterior branch of the thoracodorsal vein without flowing into the systemic circulation. To the best of our knowledge, this is the first report of selective thrombolysis using a pedicle branch to treat venous thrombosis in a pedicled flap. If major vascular branches are available in a pedicled flap, selective thrombolytic therapy may be possible without disconnecting the pedicle, as in the present case.

Noninvasive Monitoring of Deep Tissue Oxygenation in Buried Flaps by Time-Resolved Near-Infrared Spectroscopy in Pigs

BACKGROUND

Flap monitoring in reconstructive surgery is particularly important because flap failure is a dramatic event for the patient and for the medical team. Noninvasive deep tissue oxygenation monitoring is a challenge. The aim of this experimental study was to assess the performance of time-resolved near-infrared spectroscopy compared with continuous-wave near-infrared spectroscopy and with invasive oxygen partial pressure measurement in pigs.

METHODS

Thirty fasciocutaneous flaps based on the superficial epigastric inferior pedicle were harvested and buried under the transcutaneous dorsal muscle (approximately 1 cm thick). An optical probe was placed on the skin above each buried flap. For each pig, two buried flaps were performed, one submitted to arterial occlusion and one to venous occlusion. Oxyhemoglobin and deoxyhemoglobin concentrations were observed for over 40 minutes before clamping, almost 20 minutes during clamping and during a period of release of approximately 20 minutes. Variations in time-resolved near-infrared spectroscopy were compared to the oxygen partial pressure and continuous-wave near-infrared spectroscopy variations.

RESULTS

All vascular events were detected by the time-resolved near-infrared spectroscopy. During arterial clamping, oxyhemoglobin decreased rapidly, whereas deoxyhemoglobin increased moderately. The divergence of oxyhemoglobin and deoxyhemoglobin curves indicated arterial occlusion. During venous clamping, deoxyhemoglobin increased, whereas oxyhemoglobin increased briefly then remained stable or decreased moderately. The initial increases in the oxyhemoglobin and deoxyhemoglobin curves indicated venous occlusion. Oxygen partial pressure failed to detect vascular events in three cases. Continuous-wave near-infrared spectroscopy could not clearly identify vascular occlusions.

CONCLUSIONS

Thus, the authors demonstrated the relevance of time-resolved near-infrared spectroscopy to buried flap monitoring. Time-resolved near-infrared spectroscopy could differentiate between arterial occlusion and venous occlusion.

Compromised microvascular free flaps; salvage using Fogarty vascular catheter thrombectomy

Compromised free flap perfusion secondary to thrombus formation is a routinely encountered complication in microvascular free tissue transfer. Various modalities were tried out prophylactically to prevent thrombus formation, and likewise, various methods are tried for salvaging the flap with effective thrombectomy. We present the use of Fogarty vascular catheter for thrombectomy and effective salvage of the flap.

Outpatient Microsurgical Breast Reconstruction

Background:

The extensive nature of perforator-based breast reconstructions, combined with the need for postoperative flap monitoring, often leads to long hospitalizations. We present an early report demonstrating the feasibility and advantages of a modified operative technique and recovery protocol, allowing us to perform outpatient breast reconstructions with the DIEP flap. This follow-up comprises the experience gained, which is expanded to other perforator-based flaps and not limited to DIEP breast reconstructions.

Methods:

We have implemented a general protocol in patients undergoing breast reconstruction with autologous flaps, promoting early mobilization and discharge by improving postoperative pain and decreasing opioid requirements. This protocol includes intraoperative local anesthesia, a microfascial incision for DIEP harvest with rib preservation, along with prophylactic anticoagulation.

Results:

Ninety-two consecutive patients underwent autologous tissue-based breast reconstruction with DIEP, IGAP, and PAP flaps. No intraoperative complications were reported. All patients were discharged within 23 hours, without evidence of flap compromise. One patient required operative takeback for evacuation of a hematoma on postoperative day 4. No partial or total flap losses were documented. The aim of any procedure should be to get to the patient back to the preoperative status as quickly as possible, as prolonged hospitalizations are associated with higher incidences of infection, deep venous thrombosis, overall dissatisfaction, and higher overall costs of care.

Conclusions:

By using a modified operative technique, multimodal pain control, and postoperative anticoagulant therapy, outpatient perforator-flap–based breast reconstructions can be performed with high success and low complication rates.

Impacts of arterial ischemia or venous occlusion on vascularized groin lymph nodes in a rat model

BACKGROUND

Reported ischemia time of vascularized lymph nodes was 5 hours. This study investigated the effects of arterial ischemia and venous occlusion on vascularized lymph node function in rats.

METHODS

Bilateral pedicled groin lymph node flaps were raised in 27 Lewis rats. Femoral artery and vein were separated and clamped for 1, 3, 4, or 5 hour(s). Lymph node flap perfusion and drainage were assessed by laser Doppler flowmetry and indocyanine green lymphography. Histologic changes were assessed using hematoxylin and eosin stain, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), and glutathione assays.

RESULTS

Perfusion units of 2.84 ± 1.41, 2.46 ± 0.64, 2.42 ± 0.37, and 2.01 ± 0.90 were measured in arterial ischemia groups, and 1.71 ± 0.45, 2.20 ± 0.98, 1.49 ± 0.35, and 0.81 ± 0.20 in venous occlusion groups after 1, 3, 4, and 5 hours of clamping, respectively. Lymphatic drainage showed mean latency periods of 5.33 ± 0.88, 9.00 ± 3.21, 10.00 ± 2.08, and 24.50 ± 11.50 seconds in arterial clamping groups, and 25.00 ± 3.61, 26.00 ± 3.06, 23.33 ± 4.41, and 152.00 ± 0 seconds in venous clamping groups, respectively. Severe medullary and cortical congestion and hemorrhage on histology and cell damage by glutathione levels and TUNEL assay were found after 4 hours of venous clamping.

CONCLUSIONS

Arterial ischemia and venous occlusion impact the function and viability of vascularized lymph node flaps differently. The critical venous occlusion time was 4 hours.

Postoperative anticoagulation after free flap reconstruction for head and neck cancer: A systematic review

OBJECTIVE

Postoperative use of anticoagulation after free tissue transfer in head and neck ablative procedures is common practice, but a clear protocol has not been well established. The outcome measures including total flap failure, thrombosis, and hematoma formation for different anticoagulation regimens in free tissue transfer in the head and neck were reviewed.

DATA SOURCES

PubMed, Ovid, and Cochrane databases were examined for patients who underwent free tissue transfer following head and neck ablative procedures.

REVIEW METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were utilized to identify English-language studies reporting anticoagulation regimens following free tissue transfer in head and neck ablative procedures. Outcomes included total flap failure, thrombosis, and hematoma formation. Two independent reviewers assessed the quality of the articles by using the Methodological Index for Non-Randomized Studies.

RESULTS

A total of 368 articles were identified. An additional 36 articles were identified through screening of reference lists. Twenty-one of these studies met final inclusion criteria for qualitative analysis. Outcome data on total flap failure, thrombosis, and hematoma formation were extracted and analyzed for comparison against all anticoagulation regimens. Total flap failure, thrombosis, and hematoma formation rates were 4.4%, 4.5%, and 2.2%, respectively. Individual study rates ranged from 0.0% to 10.7%, 0.0% to 10.4%, and 0.6% to 7.2%, respectively.

CONCLUSIONS

There is not adequate evidence to develop a standardized anticoagulation protocol for head and neck free flap procedures. Comparable flap complications were reported between all the employed anticoagulation methods studied, though significant variability in study design among articles existed. Prospective, randomized studies are warranted to determine the optimal postoperative anticoagulation regimen following free tissue transfer of the head and neck. Laryngoscope, 128:412-421, 2018.

Multivariate analysis as an advantageous approach for prediction of the adverse outcome in head and neck microvascular reconstructive surgery

BACKGROUND

The use of a free flap has become a mainstay of reconstruction following the ablative surgery in head and neck. The success rates are about 90%, however, several factors have been described to have an adverse effect on free flap survival.

METHODS

We have performed a retrospective analysis of the treatment outcome of 93 microvascular flaps and evaluated the factors influencing the risk of flap loss including patients' age, body mass index, smoking, general medical history and previous oncological treatment.

RESULTS

Out of 93 flaps the total necrosis have been observed in 15 flaps with gradual improvement in the consecutive years. In individual analysis the patients age, BMI, and comorbidities did not reveal any significant relation. The history of any previous oncological treatment represented a significant adverse factor of success rate (p=0.035), and was even more significant when patients experienced all treatment modalities prior to the reconstructive procedure (p=0.009). Multivariate logistic regression model indicated that only surgery (p=0.0008), chemotherapy (p=0.02), cardiovascular diseases (p=0.05) and patient's age (p=0.02) represented significant factors impairing the success rate.

CONCLUSION

Incorporating multivariate analysis represents important statistical approach for better prediction of free flaps survival in head and neck reconstructive surgery. Incorporation of additional collective information could provide more precise approach in the risk of the flap loss assessment.