Survival of a free flap after arterial disconnection at six days

The Autonomization Principle in Vascularized Flaps: An Alternative Strategy for Composite Tissue Scaffold In Vivo Revascularization

Autonomization is a physiological process allowing a flap to develop neo-vascularization from the reconstructed wound bed. This phenomenon has been used since the early application of flap surgeries but still remains poorly understood. Reconstructive strategies have greatly evolved since, and fasciocutaneous flaps have progressively replaced muscle-based reconstructions, ensuring better functional outcomes with great reliability. However, plastic surgeons still encounter challenges in complex cases where conventional flap reconstruction reaches its limitations. Furthermore, emerging bioengineering applications, such as decellularized scaffolds allowing a complex extracellular matrix to be repopulated with autologous cells, also face the complexity of revascularization. The objective of this article is to gather evidence of autonomization phenomena. A systematic review of flap autonomization is then performed to document the minimum delay allowing this process. Finally, past and potential applications in bio- and tissue-engineering approaches are discussed, highlighting the potential for in vivo revascularization of acellular scaffolds.

Autonomization of pectoralis major flap in head and neck surgery

The pectoralis major flap (PMF) is one of the most used pedicled flaps for reconstructive surgery in head and neck. Basing on previous studies observing that a vascular accident or pedicle ligation not always resulted in necrosis of free flaps, sometimes after a short critical period, we describe the possibility to perform the division of the PMF pedicle. The autonomization of PMF is based on the hypothesis that the flap, after a critical period, develops a neoangiogenesis at the free portion in the recipient site. It represents a possible choice in selected patients with relapse or second tumour of the oral floor and/or mobile tongue, who have been already treated with PMF reconstruction. We provide a step-by-step description of the autonomization and use of the modified PMF. Moreover, we reported advantages and pitfalls. The modified PMF represents a safe reconstructive choice for patients advised against a free flap or a second pedicled flap, with good surgical outcomes.

Secondary Implant Augmentation in the Subpectoral Plane following Abdominal-based Perforator Flaps for Breast Reconstruction

Background

Abdominal-based perforator flaps are the gold standard for autologous breast reconstruction. However, among patients with a small-to-medium amount of redundant abdominal tissue, this may result in an inadequate breast mound. Secondary implant augmentation has been reported as one method to augment volume, address breast mound asymmetry, and enhance overall aesthetic outcome. We aim to analyze postoperative complications associated with the secondary implant augmentation following a primary breast reconstruction with abdominal perforator flaps.

Methods

This retrospective study included patients who underwent secondary implant augmentation following abdominal-based perforator flap breast reconstruction. Patient characteristics, immediate versus delayed reconstruction, type of flap used, indication for secondary augmentation as well as perioperative and postoperative complication including flap or implant loss were reviewed and analyzed.

Results

Twenty-four patients met inclusion criteria. Forty flaps were performed (16 bilateral and 8 unilateral). A total of 36 implants were placed in subpectoral plane in a secondary revision procedure. The mean time between secondary augmentation and index procedure was 22 months. Average implant volume was 270 g. No intraoperative complication or flap loss was recorded. Postoperative surgical site infection occurred in a total of 4 patients (17%) with 3 patients requiring explantation of a total of 4 implants.

Conclusions

Secondary augmentation of abdominal-based perforator flap using a permanent implant is an effective method to address volume and asymmetry and to enhance aesthetic outcome. In our study, however, we observed a higher than expected rate of postoperative infection.

Flap-Mastopexy in Autologous Breast Reconstruction: Timing and Technique

BACKGROUND

Techniques in breast reconstruction have significantly advanced the possibility to create more natural and aesthetically appealing breasts. Despite thorough preoperative planning and vigilant operative technique, symmetry remains a concern for select patients who have undergone autologous breast reconstruction. Although symmetry procedures of the contralateral breast have been well described in the literature, little has been published regarding secondary revision in the autologous reconstructed breast, leaving uncertainty as to the appropriate timing and technique for revision procedures that will not hinder the viability of the flap. In this article, we provide an effective, reproducible and safe method of mastopexy after autologous breast reconstruction.

METHODS

A retrospective review of all patients undergoing autologous breast reconstruction by a single surgeon between 2007 and 2014 was performed. Patients who underwent mastopexy after autologous breast reconstruction were included. Patient characteristics, type of reconstruction, staging of procedures, secondary operations, and complications were recorded.

RESULTS

Ten patients with asymmetric autologous breast reconstruction underwent flap mastopexy in 1 or both breasts. Indications for mastopexy included asymmetry resulting from immediate loss of autologous flaps, unilateral fat necrosis, scarring after mastectomy flap necrosis, excess ptosis, and volume asymmetries. No flap loss, fat necrosis, or nipple loss occurred after flap mastopexy.

CONCLUSIONS

The autologous mastopexy technique is a useful option in secondary refinement procedures for breast reconstruction. It provides a reliable and predictable method to adjust the inframammary fold, increase projection, and address excess ptosis. It has a low complication rate and can be safely and reliably performed as early as 3 months after initial reconstruction.

New aspects in free flap surgery: Mini-perforator flaps and extracorporeal flap perfusion

BACKGROUND

The scope of microvascular tissue transfer in the Head and Neck reaches from coverage of simple soft tissue defects to complex 3-D reconstructions using multiple or chimeric flaps. This paper summarises the presentation given at the Congress of the French Society of Oral and Maxillofacial Surgery in Marseille 2017. It was the aim of our work to add further elements to this wide spectrum of reconstructive possibilities.

METHODS

For patients with small intraoral soft tissue defects in whom the use of a radial forearm flap would not be justified because of its donor site morbidity, but who nevertheless would take a benefit from a small free flap, we used mini-perforator flaps from the lower leg. These flaps were raised with negligible morbidity. Moreover, for patients necessarily needing a free flap, but having vessel depleted, irradiated necks, we have developed a first idea of extracorporeal flap perfusion to make microvascular anastomoses unnecessary.

RESULTS

Using donor sites from the lower leg, mini-soleus and medial sural perforator flaps were raised to cover defects of 2×3 to 2×4cm at the anterior floor of the mouth or lateral tongue. The success rate was 91%, and despite their small size, the flaps helped to maintain the mobility of the tongue. The donor site morbidity was minimal. After extensive experimental work on small animals and human tissue, four flaps could successfully be transferred so far by means of extracorporeal perfusion. In these patients, autonomisation took place between 5 and 12 days.

CONCLUSIONS

Although microvascular tissue transfer already allows for reconstruction in almost any possible defect constellation, mini-perforator flaps and machine-perfused transplants seem to represent new aspects of free flap surgery, being useful extensions of the reconstructive surgeon's armament.

Generation, Endothelialization, and Microsurgical Suture Anastomosis of Strong 1-mm-Diameter Collagen Tubes

Tissue-engineered vascular grafts that are based on reconstituted extracellular matrices have been plagued by weak mechanical strength that prevents handling or anastomosis to native vessels. In this study, we devise a method for making dense, suturable collagen tubular constructs of diameter ≤1 mm for potential microsurgical applications, by dehydrating tubes of native rat tail type I collagen and crosslinking them with 20 mM genipin. Crosslinked dense collagen tubes with 1 mm inner diameter yielded ultimate tensile strength of 342 ± 15 gF and burst pressure of 1313 ± 156 mm Hg, comparable to the strength of a rat femoral artery, and supported endothelial cell adhesion and growth. End-to-end anastomosis of 0.5-mm-diameter tubes to explanted arteries displayed anastomotic strength of 82 ± 21 gF, which is sufficient for surgical applications. In vivo implantation of cell-free tubes as interpositional grafts in the rat femoral circulation yielded stable anastomosis with blood flow for 20 min. Seeded dense collagen tubes represent a promising alternative to venous graft that can potentially be used to bridge between short artery stubs in replantation surgeries.