Do two venous anastomoses decrease venous thrombosis during limb reconstruction?

Association of Dual Venous Anastomosis with Reduced Risks for Flap Congestion in Microsurgical Lower Extremity Reconstruction: A Multicenter Study

BACKGROUND

 Flap congestion related with venous thrombosis is a major cause for microsurgical lower extremity reconstruction failure. Conducting dual venous anastomosis has been suggested to reduce risks for the adverse outcomes; however, its efficacy remains controversial. This study evaluated a potential association of dual venous anastomosis with the development of flap congestion in diverse clinical situations.

METHODS

 This multicenter study included patients who underwent microsurgical lower extremity reconstruction at two institutions. They were divided into two groups based on the number of venous anastomoses-single and dual groups. Their perfusion-related complications (PRCs), including total/partial flap loss, arterial or venous insufficiency, and emergent reoperation, were compared. Independent association of the number of venous anastomoses with the outcomes was evaluated. Further analyses were conducted using propensity score matching.

RESULTS

 In total, 225 cases were analyzed, of which 92 were included in the single group and the other 133 in the dual group. The two groups had generally similar baseline characteristics. The dual group presented significantly lower rates of PRC, including total/partial flap loss, flap congestion, and emergent reoperation. Multivariable analyses showed that conducting dual venous anastomoses was associated with reduced risks for the development of overall PRC and flap congestion. These associations were more prominent when restricting analyses for cases with chronic wound and trauma (vs. oncologic defects). Similar associations were observed in the propensity score matching analysis.

CONCLUSION

 Conducting dual venous anastomosis seems associated with reduced risks for flap congestion in microsurgical lower extremity reconstruction, especially for cases with unfavorable conditions.

One Versus Two Veins in Free Anterolateral Thigh Flap Reconstruction: A Systematic Review and Meta-Analysis

There is considerable debate in the literature as to whether one or two venous anastomoses are optimal in the anterolateral thigh (ALT) free-flap reconstruction. The literature is currently devoid of a systematic review and meta-analysis of studies evaluating these procedures. This review will therefore be the first to address this clinical question. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, two authors (EW and SR) independently searched the following electronic databases: MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials (CENTRAL). Case-control, randomised control and observational studies were included. The authors did not include case reports, case series, letters or abstracts. All patients were included regardless of age, co-morbidity status, and the anatomical site of reconstruction. Venous congestion/thrombosis, flap take-back rate due to venous insufficiency, flap loss and operative time were the primary outcome measures. Secondary outcome measures included partial flap loss and haematoma formation. The Newcastle Ottawa Scale was used to assess the risk of bias in the included studies. Review Manager 5.4 data synthesis software was used for the analysis. The authors identified eight observational studies, with a total of 1741 patients reviewed, demonstrating a significantly lower flap take-back rate for a double venous anastomosis and a shorter operative time in the single venous anastomosis group. However, other reported measures, including venous congestion and flap loss, showed a non-significant difference (P>0.05). The limitations of the evidence included in this review were that all studies were observational in design. The flap take-back rate is significantly less when anastomosing two veins, and the authors recommend that utilising a second vein can circumvent the caveat of venous compromise.

Analysis of Anastomotic Venous Factors in Traumatic Lower Extremity Injuries Reconstructed by Free Flap

Background

Venous thrombosis has been shown to be the most frequent cause of free flap failure in traumatic lower extremity injuries. However, the roles of various anastomotic venous factors, including venous anastomosis (end-to-end (ETE) or end-to-side (ETS)), venous outflow (one vein or two veins), and recipient venous selection (deep or superficial vein), remain unclear. This retrospective study aims to investigate factors contributing to microvascular complications in patients with lower extremity Gustilo type IIIB/IIIC injuries reconstructed by free flap with a focus on the three abovementioned venous factors.

Methods

A total of 44 flap treatment outcomes of 41 patients with these injuries from 2015 to 2020 were assessed according to the three venous factors (type of anastomosis, venous outflow, and vein selection).

Results

The average patient age was 52 years, with the majority (75.6%) being male. Eight patients (18.2%) returned to the operating room due to venous thrombosis, and five patients (11.4%) experienced total flap failure. The following factors were suspected to have contributed to venous thrombosis: vein size mismatch (n = 2) and recipient vein insufficiency possibly due to post-traumatic vessel disease (PTVD) (n = 6). End-to-side (ETS) anastomoses showed lower venous thrombosis rates than end-to-end (ETE) anastomoses (6.3% versus 25%, p = 0.22), two-vein outflows had lower rates than one (8.3% versus 30%, p = 0.07), and deep veins had the lowest thrombosis rates (7.7%), whereas superficial veins had the highest (38.5%).

Conclusion

The key venous factors in preventing venous thrombosis include using as many two-vein ETS anastomoses as possible to deep recipient veins.

Anti-thrombotic and anti-inflammatory activity of sulodexide compared to aspirin in the rat model

BACKGROUND

Although the number of vascular surgeries performed is increasing, the incidence of complications associated with this surgery has not improved and re-operations are frequently required. Thrombosis in a vessel is the most hazardous postoperative complication.

OBJECTIVE

The aim of this study was to evaluate the anti-thrombotic and anti-inflammatory effects of sulodexide compared to aspirin in a rat model.

METHODS

We divided the animals into three groups (sham (saline), aspirin, and sulodexide). The abdominal aorta was surgically opened and closed, primarily with 8/0 Prolene sutures. Postoperatively, saline, aspirin, or sulodexide was administered by oral gavage for 14 days to the rats. The degree of neovascularization, thrombus, calcification, inflammatory infiltrates, and fibrosis were analyzed histopathologically by hematoxylin and eosin staining.

RESULTS

There was no significant difference in the incidence of postoperative thrombogenesis, but less calcification and inflammatory infiltrates were observed in the sulodexide group compared to the aspirin group. Histopathologic score revealed less infiltration of inflammatory cells and mild calcification for the sulodexide group (0.17±0.41 and 1.33±0.52, respectively) compared to the aspirin group (0.67±0.52 and 1.67±0.52, respectively) at days 14.

CONCLUSIONS

This study offers the possibility that sulodexide could be used as an aspirin substitute for the postoperative management of vascular patients, with low gastrointestinal discomfort. In addition, it may also offer reduced postoperative calcification and inflammation.