AV loop free flap: an interdisciplinary approach for perineal and sacral defect reconstruction after radical oncological exenteration and radiation in a colorectal cancer patient

Use of a collagen-elastin matrix with split-thickness skin graft for defect coverage in complex wounds

OBJECTIVE

Severe soft tissue damage with destruction of the dermis requires plastic reconstructive treatment. For multimorbid patients or patients unable to undergo major reconstructive surgery, use of dermal substitutes, such as a collagen-elastin matrix (CEM) with a split-thickness skin graft (STSG), instead of local or free flap surgery, may be a valid and easy treatment option. We aimed to investigate and compare the outcomes and rate of successful defect reconstruction using CEM plus STSG, using either a one-step approach (simultaneous CEM and STSG) or a two-step approach (CEM and negative wound pressure therapy (NPWT), with secondary STSG transplantation).

METHOD

A single-centre, retrospective follow-up study of patients who had received CEM was conducted. Wounds had been treated with an STSG transplantation covering a CEM (MatriDerm, MedSkin Solutions Dr. Suwelack AG, Germany). Previous attempts at wound closure with conventional methods had failed in the selected patient population, which would usually have resulted in flap surgery.

RESULTS

Overall, 46 patients were included (mean age 60.9±20.0 years), with a total of 49 wound sites. We analysed 38 patients with wounds that did not require flap coverage; 18 patients received the one-step approach and 20 patients received the two-step approach. The mean follow-up in these patients was 22±11.5 months, and one patient was lost to follow-up. Overall, 29 (78.4%) wounds remained closed. Wounds which did not successfully heal were related to comorbidities, such as diabetes, alcohol misuse and smoking. Using the one-step approach, long-term defect coverage was achieved in 13 (76.5%) wounds and 16 (80.0%) wounds were closed using the two-step approach. However, there was no statistically significant differences between the one- or two-step approaches regarding the rate of development of a wound healing disorder.

CONCLUSION

Wound closure was achieved in 38 complex wounds using CEM plus STSG, while 11 wounds needed secondary flap coverage. In the flap-free wounds, there were no statistically significant differences between the one-step versus two-step approach. Using a simple defect reconstruction algorithm, we successfully used CEM plus STSG to treat complex wounds.

Heterogeneous Maturation of Arterio-Venous Fistulas and Loop-Shaped Venous Interposition Grafts: A Histological and 3D Flow Simulation Comparison

Vascular graft maturation is associated with blood flow characteristics, such as velocity, pressure, vorticity, and wall shear stress (WSS). Many studies examined these factors separately. We aimed to examine the remodeling of arterio-venous fistulas (AVFs) and loop-shaped venous interposition grafts, together with 3D flow simulation. Thirty male Wistar rats were randomly and equally divided into sham-operated, AVF, and loop-shaped venous graft (Loop) groups, using the femoral and superficial inferior epigastric vessels for anastomoses. Five weeks after surgery, the vessels were removed for histological evaluation, or plastic castings were made and scanned for 3D flow simulation. Remodeling of AVF and looped grafts was complete in 5 weeks. Histology showed heterogeneous morphology depending on the distribution of intraluminal pressure and WSS. In the Loop group, an asymmetrical WSS distribution coincided with the intima hyperplasia spots. The tunica media was enlarged only when both pressure and WSS were high. The 3D flow simulation correlated with the histological findings, identifying “hotspots” for intimal hyperplasia formation, suggesting a predictive value. These observations can be useful for microvascular research and for quality control in microsurgical training.

Best Solutions for Perineal and Pressure Sore Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand variations of the myocutaneous rectus abdominis muscle flap as it is used for perineal reconstruction and discuss common and alternative options for perineal defect reconstruction. 2. Review primary options and alternatives to pressure sore reconstruction if the primary option is not available and recognize when pressure sore reconstruction is not feasible. 3. Highlight pertinent anatomy and techniques for the flaps described.

SUMMARY

Perineal reconstruction following tumor resection is often complicated by irradiated tissue and multiple comorbidities, making reconstruction challenging. Management of these conditions can have complication rates as high as 66 percent, which further compounds the costs and implications of managing these wounds. These complication rates can be significantly decreased using flap closure rather than primary closure. Pressure ulcers also occur in patients with poor overall health, multiple comorbidities, and often numerous prior failed reconstruction attempts. Comprehensive management of pressure sores is a significant burden to the health care system, at a cost of $9.1 to $11.6 billion per year. There exists an extensive body of literature describing the pathophysiology and management strategies for these problems. The focus of this article is to discuss best solutions for perineal and pressure ulcer reconstruction, and to explore alternative options for reconstruction.

Skeletal regeneration for segmental bone loss: Vascularised grafts, analogues and surrogates

Massive segmental bone defects (SBD) are mostly treated by removing the fibula and transplanting it complete with blood supply. While revolutionary 50 years ago, this remains the standard treatment. This review considers different strategies to repair SBD and emerging potential replacements for this highly invasive procedure. Prior to the technical breakthrough of microsurgery, researchers in the 1960s and 1970s had begun to make considerable progress in developing non autologous routes to repairing SBD. While the breaktthrough of vascularised bone transplantation solved the immediate problem of a lack of reliable repair strategies, much of their prior work is still relevant today. We challenge the assumption that mimicry is necessary or likely to be successful and instead point to the utility of quite crude (from a materials technology perspective), approaches. Together there are quite compelling indications that the body can regenerate entire bone segments with few or no exogenous factors. This is important, as there is a limit to how expensive a bone repair can be and still be widely available to all patients since cost restraints within healthcare systems are not likely to diminish in the near future. STATEMENT OF SIGNIFICANCE: This review is significant because it is a multidisciplinary view of several surgeons and scientists as to what is driving improvement in segmental bone defect repair, why many approaches to date have not succeeded and why some quite basic approaches can be as effective as they are. While there are many reviews of the literature of grafting and bone repair the relative lack of substantial improvement and slow rate of progress in clinical translation is often overlooked and we seek to challenge the reader to consider the issue more broadly.

[Bilateral pedicled gracilis muscle flap and bilateral gluteus muscle flap for multiple-stage reconstruction of vagina, pelvis and perineal region]

Plastic reconstructions of oncological anorectal defects often prove to be very difficult and lead to prolonged hospitalisation due to severe bacterial contamination, neoadjuvant radiotherapy and chemotherapy and difficult anatomical conditions. There is no common standard for plastic reconstruction in such cases. We present a patient diagnosed with distal rectal cancer with infiltration of the anus and vagina, who underwent radical tumour resection of the rectum and anus as well as partial resection of the vagina. A severe necrotising infection occurred post-surgery, which resulted in an extensive defect of the pelvis and perineal region. This article provides a retrospective clinical evaluation and photographic documentation of the reconstruction of the vagina, pelvis and perineal region with a bilateral gracilis and gluteus muscle flap.

Common Carotid-to-Internal Jugular Arteriovenous Loop for Single-Stage Microsurgical Reconstruction in the Radiated Vessel-Depleted Neck

ABSTRACT

Management of head and neck defects in a radiated field can be quite challenging owing to the dearth of vasculature and significant degree of post-radiation fibrosis. In this setting, arteriovenous (AV) loop vascular grafts can bypass nonviable local vessels to provide viable and reliable inflow and outflow vessels for free tissue transfer in an otherwise hostile environment. Prior reports of the Corlett loop utilizing a cephalic vein transposition has been described however a common carotid-to-internal jugular AV loop has not been recently reported. Three patients underwent carotid artery to internal jugular vein AV loop creation to facilitate free-flap reconstruction secondary to radiation-induced vessel depletion. The specific technique described utilizes the saphenous vein as a donor and spares the cephalic vein for the possibility of flap complication. All three cases resulted in successful reconstruction, maintaining healthy tissue, vascular flow, and flap viability at all follow-up intervals. In our experience, vascular augmentation via AV loop formation provides reliable vascular inflow and outflow in the vessel-depleted neck to facilitate microvascular reconstruction. Sparing the cephalic vein yields an additional salvage mechanism in the event of venous congestion.

The Historical Role of the Plastic Surgeon in Spine Reconstruction

Wound complications occur in up to 19% of patients undergoing complex spine surgery. The role of the plastic surgeon in complex and redo spine surgery is important and evolving. Classically, plastic surgeons have been involved in the management of patients who develop wound complications following surgery. This involves reconstruction of posterior trunk defects with locoregional fasciocutaneous, muscle, and free tissue transfers. There has also been an increasing role for plastic surgeons to become involved in prophylactic closures of complex and/or redo spine surgeries for high-risk populations. Identification of patients with comorbidities and likelihood for multiple reoperations who are prophylactically treated with complex closure with or without local muscle flaps could significantly decrease the postoperative wound complications.