Quantitative Relationship Between Vascular Kinking and Twisting

Splinting Technique for Venous Anastomosis in Lower Limb Free Flap Reconstruction

Lower limb reconstruction of the distal third following tumor extirpation or trauma is a complex procedure. The use of free flaps to cover lower limb defects is a common practice in our department. Vascular kinking or compression resulting in thrombosis is the leading cause of venous congestion and free flap failure in lower limb reconstruction. We describe a simple and inexpensive technique to avoid venous kinking during microvascular anastomosis in free flap reconstructions in the lower leg, which has proved safe in a cohort of patients.

Evaluation of remodeling and regeneration of electrospun PCL/fibrin vascular grafts in vivo

The success of artificial vascular graft in the host to obtain functional tissue regeneration and remodeling is a great challenge in the field of small diameter tissue engineering blood vessels. In our previous work, poly(ε-caprolactone) (PCL)/fibrin vascular grafts were fabricated by electrospinning. It was proved that the PCL/fibrin vascular graft was a suitable small diameter tissue engineering vascular scaffold with good biomechanical properties and cell compatibility. Here we mainly examined the performance of PCL/fibrin vascular graft in vivo. The graft showed randomly arranged nanofiber structure, excellent mechanical strength, higher compliance and degradation properties. At 9 months after implantation in the rat abdominal aorta, the graft induced the regeneration of neoarteries, and promoted ECM deposition and rapid endothelialization. More importantly, the PCL/fibrin vascular graft showed more microvessels density and fewer calcification areas at 3 months, which was beneficial to improve cell infiltration and proliferation. Moreover, the ratio of M2/M1macrophage in PCL/fibrin graft had a higher expression level and the secretion amount of pro-inflammatory cytokines started to increase, and then decreased to similar to the native artery. Thus, the electrospun PCL/fibrin tubular vascular graft had great potential to become a new type of artificial blood vessel scaffold that can be implanted in vivo for long term.

Role of computed tomography angiography in the diagnosis of vascular stenosis in head and neck microvascular free flap reconstruction

The aim of this study was to evaluate the role of computed tomography angiography (CTA) in the diagnosis of vascular stenosis at the vascular pedicle of head and neck microvascular free flaps. A prospective study was done of 65 consecutive patients (49 male, 16 female; mean age 55 years) who had undergone head and neck microvascular free flap reconstruction. All patients underwent 64-slice CTA of the carotid artery. Post-processing with volume rendering reconstruction of CTA images was done. There was excellent inter-observer agreement (weighted kappa=0.82, 95% confidence interval (CI) 0.74-0.93) in grading of the degree of vascular stenosis. The true sensitivity of CTA for diagnosis of stenosis of the vascular pedicle to the flap was 63% (95% CI 63-100%). Patients with failed flaps showed complete occlusion (n=2) on CTA and underwent a replacement flap procedure. Patients with failing flaps showed severe stenosis (n=6) of the vascular pedicle on CTA and underwent revision surgery. There was no change in the degree of stenosis on follow-up CTA for patients with moderate stenosis (n=9). CTA is a reliable, non-invasive, high-quality imaging tool for the diagnosis and grading of vascular stenosis of the vascular pedicle of head and neck microvascular free flaps.

Hepatic artery kinking during liver transplantation: survey and prospective intraoperative flow measurement

BACKGROUND

Hepatic artery thrombosis (HAT) represents the most common vascular complication occurring after liver transplantation (LT). Herein, we report the results of a prospective study of hepatic artery flow (HAF) measurement during abdominal wall closure after LT along with the results of an international survey of procedures adopted, in order to avoid the arterial kinking (AK) in case of long artery.

METHODS

Sixty-four surgeons were asked regarding the different procedures used to avoid AK in the presence of long artery. We prospectively assessed the HAF during three phases of LT in 26 consecutive LT performed in patients with a long HA: after completion of the biliary anastomosis (M0), and partial abdominal wall closure with (M1w) or without (M1w/o) hepatic artery anti-kinking method (HAAK).

RESULTS

Sixty (93.7 %) surgeons replied to the survey: 44 (73.3 %) surgeons cut the artery as short as possible, of whom 38 (86.3 %) interposed an oxidized polymer or the omentum, and six (13.7 %) used other systems. Fourteen (23.3 %) surgeons did not use any interposition methods. The remaining two (3.3 %) surgeons left a long artery without HAAK. In our cohort we obtained the following HAF measures: M0 152 mL/min (89-205), M1 without HAAK 114 (66-168) and M1 with HAAK procedure 158 (91-219) (p = 0.002).

CONCLUSIONS

Our survey confirms that no consensus is currently available regarding the most effective method for avoiding AK. Kinking occurs most probably when the liver is released in its final position. The utilization of an interposition method could ensure the maintenance of a correct HAF.