Vascular Complications After Radiotherapy in Head and Neck Free Flap Reconstruction

Abstract

Radiotherapy as a risk factor for free flap failure has been widely debated. The purpose of this study was to investigate vascular complications in free flap surgery at a center advocating preoperative radiotherapy. On the basis of previous experimental studies, we also aimed to investigate temporal aspects of vascular complications in both arteries and veins. Furthermore, we aimed to study the effect of tissue plasminogen activator (tPA), because irradiated microvascular recipient vessels are associated with impaired fibrinolysis.A retrospective review was conducted for 344 consecutive head and neck microvascular reconstructions. Radiotherapy was administered previously in 283 (82%) of the cases, median dose 64 Gy. Flap outcome, vascular complications, and salvage attempts were identified, along with time elapsed from completed radiotherapy, described as early (<6 weeks), delayed (6-15 weeks) and late (>15 weeks) reconstructions.Total flap loss was more common in irradiated cases (P = 0.035), among which flap failure increased with time elapsed from the last radiotherapy session to surgery (P = 0.021). Among 30 registered vascular complications, venous thrombosis was the most common type and increased in delayed, compared to early, reconstructions (P = 0.012). Increased salvage rates were observed when tPA was administered intraoperatively (P = 0.015).The present study indicates that previous radiotherapy is a risk factor for head and neck free flap failure, especially in delayed reconstructions. This may be linked to previous findings of impaired fibrinolysis in irradiated microvascular recipient veins, which is further supported by the beneficial effect of tPA during salvage surgery. We emphasize the importance of early reconstruction after radiotherapy and suggest that there is a role for fibrinolytic agents during free flap salvage surgery in previously irradiated subjects.

Utilization of Intraparotid Segments of Superficial Temporal Vessels for Head and Scalp Free Flap Microanastomosis: A Clinical, Histological, and Cadaveric Study

“…Other authors have reported total flap loss rates for head and neck reconstruction anywhere from 1.7 to 13.6%, with flap loss being more common in irradiated sites and late reconstructions. [24][25][26][27] Half of our cohort included irradiated patients; thus, these results are in line with those reported in the literature. Data regarding incidence intraoperative vasospasms, specifically in free flaps utilizing SVTS, appears to be limited in current literature.…”

Autologous fat transplantation alters gene expression patterns related to inflammation and hypoxia in the irradiated human breast

“…Efforts to explain radiation‐induced fibrosis, for example, by genetic variation have remained largely inconclusive. The authors have previously reported alterations in global gene expression in irradiated recipient vessels from free‐flap breast and head–neck reconstructions, but few studies have been able to describe gene expression patterns in irradiated breast adipose tissue. Furthermore, the effect of AFT on gene expression profiles in humans is largely unknown.…”

The utility of the musculocutaneous anterolateral thigh flap in pharyngolaryngeal reconstruction in the high‐risk patient

“…In a single institute analysis of 984 patients with 137 previously irradiated fields, Bourget et al determined radiation to be associated with a postoperative free flap complication rate of 47%, a reoperation rate of 22%, and a 28% infection rate. Tall et al, in a review of 283 cases with previous radiation, showed that total flap loss was more common in this group of patients, with flap failure increasing with time elapsed from surgery . In addition, they determined that flap salvage rates increased with the use of tissue plasminogen activator (tPA), further supporting the detrimental effects radiation has on the microvasculature.…”

“…22 This leads to hypovascular tissue with poor healing capability, with a recent meta-analysis of 24 studies that total flap loss was more common in this group of patients, with flap failure increasing with time elapsed from surgery. 23 In addition, they determined that flap salvage rates increased with the use of tissue plasminogen activator (tPA), further supporting the detrimental effects radiation has on the microvasculature. It is therefore imperative that extraordinary measures be taken in this group of patients to minimize post-operative morbidity.…”