Microsurgery and vasospasms: Spasms' predictive factors during harvesting.

Background: Vasospasm (VS) in microsurgery is a source of surgical complications, repeat operations, stress for the patient and the surgical team, as well as increased length of stay. Various risk factors have been identified but knowledge regarding the implicated mechanism remains limited.

Hypothesis: Our objective was to determine if the harvesting conditions for microsurgical toe transfers could increase the risk of VS. Our secondary objective was to determine the correlation between VS occurrence before flap division, and the occurrence of vascular complications after completion of vascular anastomoses.

Patients and methods: Primary endpoints were the existence of locoregional anaesthesia of the lower limb, the Gilbert classification, the nature of the graft taken from the foot, the characteristics of the patients and smoking status. Our secondary endpoints were the presence of secondary VS or microsurgical failure. This series consists of 14 toe transfers over a 30-month period. Primary VS was defined as occurring prior to flap division, while secondary VS occurred after transfer.

Results: In this series, we identified 4 cases of primary VS. The average age of the operated population was 30.6 ± 11.2 years (16-58). The patients who presented with primary VS had a mean age of 35.3 ± 16.2 years (21-58), with no statistical difference with the other group (p = 0.54). There was a statistically significant difference between the absence of locoregional anaesthesia and the occurrence of primary VS in toe transfer (p = 0.0008). Microsurgical failure occurred in 1 case. This failure was linked to the presence of a primary VS. Gilbert's classification and type of graft were not predictive of VS (p = 0.15 and p = 0.08, respectively). The occurrence of secondary VS was statistically linked to the occurrence of primary VS (p = 0.009).

Discussion: The occurrence of VS remains unpredictable and the effectiveness of available treatments is debated in the literature. Faced with the failure of curative treatments, this study aimed to determine predictive factors for VS. The existence of secondary VS, when prolonged and non-responsive to conventional measures, can lead to anastomotic revision. Performing locoregional anaesthesia on the lower limb makes it possible to effectively combat the occurrence of VS. The absence of primary VS was correlated with an absence of secondary VS and an absence of microsurgical failure. In addition to controlling vasospasm, regional anaesthesia provides effective analgesia at the harvesting site.

Level of evidence: IV.