The position of ‘shunt restriction’ along an arterialized vein affects venous congestion and flap perfusion of an arterialized venous flap

Reconstruction of digital defects using the venous flap offer several advantages but remained unpopular owing to levels of venous congestion rates. We performed animal studies to test the hypothesis that an arterio-venous shunt increases pressure for peripheral flap perfusion and decreases venous congestion. Using an abdominal adipofascial flap model in six male Sprague–Dawley rats, microcirculation was modified as follows: type I – arterial flap; type II – flow-through arterio-venous flap (AVF); and type III – shunt-restricted AVF. In type I flaps, blood flow was observed to be unidirectional in both arterioles and venules. In type I flaps, blood flow was observed to be unidirectional in both arterioles and venules. In type II flaps, blood flow oscillated without a dominant direction and came to a standstill. In type III flaps, blood flowed proximally in a reverse direction whereas distally, flow was similar to type I flaps. In a clinical series, 21 patients received a total of 22 shunt-restricted AVFs. All 22 clinical flaps survived; four flaps suffered epidermolysis but recovered without full thickness loss.

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One Versus 2 Venous Anastomoses in Free Flap Surgery: A Systematic Review and Meta-Analysis

Plastic Surgery ◽

10.1177/2292550317740693 ◽

2017 ◽

Vol 26 (2) ◽

pp. 91-98

Author(s):

Jennifer L. K. Matthews ◽

Noor Alolabi ◽

Forough Farrokhyar ◽

Sophocles H. Voineskos

Keyword(s):

Systematic Review ◽

Free Flap ◽

Meta Analysis ◽

Venous Congestion ◽

Flap Surgery ◽

Flap Failure ◽

Free Flap Surgery ◽

Significant Difference ◽

Reoperation Rates ◽

Venous Flap

Background: The necessity of a second venous anastomosis in free flap surgery is controversial. The purpose of this systematic review is to determine whether venous flap failure and reoperation rates are lower when 2 venous anastomoses are performed. The secondary objective is to determine whether venous flap failure and reoperation rates are lower when the 2 veins are from 2 different drainage systems. Methods: A comprehensive search of the literature identified relevant studies. Investigators independently extracted data on rates of flap failure and reoperation secondary to venous congestion. A meta-analysis was performed; odds ratios (ORs) were pooled using a random-effects model and 95% confidence intervals (CIs). Results: Of 18 190 studies identified, 15 were included for analysis. The mean sample size was 287 patients (minimum = 102, maximum = 564). No statistically significant difference in venous flap failure was found when comparing 1 versus 2 venous anastomoses (OR: 1.35; 95% CI: 0.46-3.93). A significant decrease in reoperation rate due to venous congestion was shown (OR: 3.03; 95% CI: 1.64-5.58). The results favor using 2 veins from 2 different systems over veins from the same system (OR: 0.16; 95% CI: 0.02-1.27). Conclusions: There is low-quality evidence suggesting that the use of 2 venous anastomoses will lower the rate of reoperation due to venous congestion. There are insufficient data published to meaningfully compare outcomes of flaps with 2 venous anastomoses from different systems to flaps with anastomoses from the same system.

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