The split vein graft “splint” to avoid kinking and compression of the vascular pedicle

Tri-Layered Vascular Grafts Guide Vascular Cells’ Native-like Arrangement

Bionic grafts hold great promise for directing tissue regeneration. In vascular tissue engineering, although a large number of synthetic grafts have been constructed, these substitutes only partially recapitulated the tri-layered structure of native arteries. Synthetic polymers such as poly(l-lactide-co-ε-caprolactone) (PLCL) possess good biocompatibility, controllable degradation, remarkable processability, and sufficient mechanical strength. These properties of PLCL show great promise for fabricating synthetic vascular substitutes. Here, tri-layered PLCL vascular grafts (TVGs) composed of a smooth inner layer, circumferentially aligned fibrous middle layer, and randomly distributed fibrous outer layer were prepared by sequentially using ink printing, wet spinning, and electrospinning techniques. TVGs possessed kink resistance and sufficient mechanical properties (tensile strength, elastic modulus, suture retention strength, and burst pressure) equivalent to the gold standard conduits of clinical application, i.e., human saphenous veins and human internal mammary arteries. The stratified structure of TVGs exhibited a visible guiding effect on specific vascular cells including enhancing endothelial cell (EC) monolayer formation, favoring vascular smooth muscle cells’ (VSMCs) arrangement and elongation, and facilitating fibroblasts’ proliferation and junction establishment. Our research provides a new avenue for designing synthetic vascular grafts with polymers.

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.

Simultaneous Restoration of Swallowing and Voice Function With Ileocolon Free Flap

BACKGROUND

Free ileocolon flap is a reliable technique allowing simultaneous restoration of swallowing and speech. The aim is to report our 6-year experience in a single center.

METHODS

Thirty-seven patients treated between 2010 and 2015 were included in the study. Swallowing and speech function were evaluated in 27 patients with a 7-point and 5-point Likert scale, respectively. Moreover, 12 of them consented to voice spectrum analysis (VSA).

RESULTS

Complications noted were: aspiration (3), esophagocutaneous fistula (2), and stricture (1). Seven patients experienced self-limited diarrhea. Regarding swallowing function, 77.8% scored ≥5 on Likert scale whereas speech Likert scale showed excellent results (score >12) in 74%. VSA demonstrated mean phonation time of 10.75 seconds, mean frequency of 131 Hz and mean dynamic range of 56 dB.

CONCLUSION

In experienced hands, the ileocolon flap is safe and effective, particularly in patients with long-life expectancy, providing good swallowing and speech function without further procedures/prostheses.

The safety and benefit of using oxidized regenerated cellulose to position free flap pedicle in head and neck reconstruction

BACKGROUND

Oxidized regenerated cellulose (ORC; Surgicel®; Ethicon, Neuchâtel, Switzerland) is an absorbable hemostatic agent used for hemostasis in operation, although some surgeons use it to position free flap pedicles. The increasing risk of vessel compromise is a huge concern. However, no scientific data to date demonstrate the safety and benefit of using ORC in microvascular surgery. In the present study, we compared the outcome of microvascular head and neck reconstruction with and without pedicle placement using ORC.

MATERIALS AND METHODS

From January 2015 to December 2017, we reviewed patients undergoing microvascular surgery with free fibular osteocutaneous flap in our hospital. The patients were divided into the ORC group and non-ORC group and their baseline characteristics and outcomes were compared.

RESULTS

In total, there were 27 patients in the ORC group and 67 in the non-ORC group. The non-ORC group had significantly higher cigarette consumption (70.4% vs. 89.6%; p = .022). The outcome of the ORC group was better regarding arterial thrombosis (0% vs. 3%), flap failure (0% vs. 4.5%), hematoma (7.4% vs. 10.4%), and wound complications (25.9% vs. 44.8%). The ORC group had a worse result than the non-ORC group for vein thrombosis (7.4% vs. 4.5%) and duration of hospitalization (24.111 days vs. 23.627 days). However, none of above results was significant.

CONCLUSIONS

Though this study was underpowered to detect the differences, the results showed a trend toward better outcomes of flaps and wounds in the ORC group. It seems that using ORC in this field is safe and beneficial.