The Blue-Blood Porcine Chest Wall: A Novel Microsurgery Training Simulator for Internal Mammary Vessel Dissection and Anastomosis.

BACKGROUND: Preparation of the internal mammary artery (IMA) is a critical step in autologous breast reconstruction. Intraoperatively, there is limited opportunity for residents to practice this skill. Porcine models provide highly realistic simulation for vascular surgery; however, use of live laboratory pigs is expensive, inconvenient, and offers limited opportunity for repetitive training. We aimed to develop an inexpensive and effective training model for IMA preparation. This article describes creation of a novel microsurgical model using cadaveric chest walls of Wisconsin Miniature Swine embedded in a modified mannequin thorax and augmented with a blue-blood perfusion system. METHODS: Anatomic comparison: five porcine chest walls were dissected, and various anatomic measurements were made for anatomic comparison to existing human data in the literature. Model assembly: the chest wall is prepared by cannulating the proximal and distal ends of the internal mammary vessels with angiocatheters, which are then connected to the blue-blood perfusion system. The model is assembled in four layers including: (1) a mannequin thorax with a window removed to expose the first to fourth intercostal spaces, bilaterally, (2) a layer of foam simulating fat, (3) the perfused pig chest wall, and (4) a second mannequin shell placed posteriorly for support. RESULTS: The porcine chest walls are similar to humans with regards to vessel size and location. This model can be assembled quickly, with a one-time approximate cost of $55.00, and allows for six training sessions per specimen. The model allows residents to practice the key steps of IMA preparation including dissection, elevation of perichondria, and vascular anastomosis while working at a depth that closely simulates the human thorax. Continuous blue-blood perfusion provides immediate feedback on anastomosis quality. CONCLUSION: Overall, this novel model can provide inexpensive and realistic simulation of internal mammary vessel preparation and anastomosis.

Dermal Autografts in Breast Reconstruction: A Review of Past and Current Trends.

Breast cancer affects 1 in 8 women. As the treatment of breast cancer evolves, breast reconstruction does as well. Implant-based reconstructions are increasing, leading to increased use of acellular dermal matrix (ADM) for better implant positioning. Acellular dermal matrices are derived from cadaveric skin and are processed to be immunologically inert. However, ADM can be costly and can have complications such as seroma and infection. This has led to the development of dermal autografts. These were first used in postmastectomy breast reconstruction in women with redundant breast skin that was deepithelialized and used for lower pole coverage of tissue expanders and implants. This evolved into harvesting dermal autografts from the abdomen. Later studies evaluated the use of meshed dermal autografts. Histological analysis of ADM versus dermal autografts shows that there are increased vessels within dermal autografts compared with ADM. This potentially contributes to the decreased complication rate seen with autografts. In addition, one study showed equivalent results in aesthetic outcomes and capsular contracture between ADM and dermal autograft. Analysis of cost has shown that ADM is significantly more costly than harvesting a dermal autograft. Physician reimbursement is also higher for dermal autografts. This review article seeks to summarize key studies that highlight the feasibility of using dermal autografts in breast reconstruction.

Beyond the Core Suture: A New Approach to Tendon Repair.

Despite significant improvements in zone II flexor tendon repair over the last 2 decades, function-limiting complications persist. This article describes 2 novel repair techniques utilizing flexor digitorum superficialis (FDS) autografts to buttress the flexor digitorum profundus (FDP) repair site without the use of core sutures. The hypothesis being that the reclaimed FDS tendon autograft will redistribute tensile forces away from the FDP repair site, increasing overall strength and resistance to gapping in Zone II flexor tendon injuries compared with the current clinical techniques. METHODS: Two novel FDP repair methods utilizing portions of FDS have been described: (1) asymmetric repair (AR), and (2) circumferential repair. Ultimate tensile strength and cyclical testing were used to compare novel techniques to current clinical standard repairs: 2-strand (2-St), 4-strand (4-St), and 6-strand (6-St) methods. All repairs were performed in cadaveric sheep tendons (n = 10/group), by a single surgeon. RESULTS: AR and circumferential repair techniques demonstrated comparable ultimate tensile strength to 6-St repairs, with all 3 of these techniques able to tolerate significantly stronger loads than the 2-St and 4-St repairs (P < 0.0001). Cyclical testing demonstrated that AR and circumferential repair were able to withstand a significantly higher total cumulative force (P < 0.001 and P = 0.0064, respectively) than the 6-St, while only AR tolerated a significantly greater force to 2-mm gap formation (P = 0.042) than the 6-St repair. CONCLUSION: Incorporating FDS as an autologous graft for FDP repair provides at least a comparable ultimate tensile strength and a significantly greater cumulative force to failure and 2-mm gap formation than a traditional 6-St repair.

Alternative Approach for Occipital Headache Surgery: The Use of a Transverse Incision and "W" Flaps.

The most commonly used approach for a greater occipital nerve decompression is through a vertical midline incision, with multiple authors reporting favorable long-term outcomes. A transverse approach to the occipital nerves has been described, yet it does not include the use of fat flaps to insulate the decompressed nerves. In this study, we describe the use of a single transverse incision with modified "W" fat flaps to decompress both the greater and lesser occipital nerves. This allows for wider exposure of the nerves without the need for an additional incision to access the lesser occipital nerve. The described technique provides increased reach and versatility of the fat flap, allowing for coverage over a longer course of the nerve and further cephalad, close to the bony skull base. In addition, the fat flaps cover the greater occipital nerve closer to its native position, as opposed to bringing the nerve into a subcutaneous position. This, theoretically, keeps the nerve in a more protected deep position and technically makes it easier to avoid any tendency for kinking the nerves while wrapping them with the fat flap. Our experience has demonstrated that this modified technique is not only safe but also efficacious in affecting a statistically significant reduction (70% improvement, P = 0.004) in migraine headache index and HIT-6 scores. This study provides further evidence that nerve decompression for headache following the principles described by Guyuron is an efficacious and reproducible procedure and that a proper nerve decompression is effective in reducing headache.

Major Histocompatibility Complex-Matched Arteries Have Similar Patency to Autologous Arteries in a Mauritian Cynomolgus Macaque Major Histocompatibility Complex-Defined Transplant Model.

Background Arterial bypass and interposition grafts are used routinely across multiple surgical subspecialties. Current options include both autologous and synthetic materials; however, each graft presents specific limitations. Engineering artificial small-diameter arteries with vascular cells derived from induced pluripotent stem cells could provide a useful therapeutic solution. Banking induced pluripotent stem cells from rare individuals who are homozygous for human leukocyte antigen alleles has been proposed as a strategy to facilitate economy of scale while reducing the potential for rejection of induced pluripotent stem cell-derived transplanted tissues. Currently, there is no standardized model to study transplantation of small-diameter arteries in major histocompatibility complex-defined backgrounds. Methods and Results In this study, we developed a limb-sparing nonhuman primate model to study arterial allotransplantation in the absence of immunosuppression. Our model was used to compare degrees of major histocompatibility complex matching between arterial grafts and recipient animals with long-term maintenance of patency and function. Unexpectedly, we (1) found that major histocompatibility complex partial haplomatched allografts perform as well as autologous control grafts; (2) detected little long-term immune response in even completely major histocompatibility complex mismatched allografts; and (3) observed that arterial grafts become almost completely replaced over time with recipient cells. Conclusions Given these findings, induced pluripotent stem cell-derived tissue-engineered blood vessels may prove to be promising and customizable grafts for future use by cardiac, vascular, and plastic surgeons.

The Surgical Treatment of Adult Acquired Buried Penis Syndrome: A New Classification System.

BACKGROUND: Adult acquired buried penis syndrome may be associated with an inability to void, sexual dysfunction, and recurrent infection. Previously published classification systems rely on intraoperative findings, such as penile skin quality. OBJECTIVES: The purpose of this study was to evaluate outcomes after adult acquired buried penis repair and to develop a classification system based on preoperative assessment. METHODS: The authors reviewed data from patients who underwent buried penis reconstruction at a single institution. Patient history and physical examination guided the development of a classification system for surgical planning. RESULTS: Of the 27 patients included, the mean age was 56 ± 15 years and mean body mass index was 49 ± 14 kg/m2. Patients were classified into 4 groups based on examination findings: (I) buried penis due to skin deficiency, iatrogenic scarring, and/or diseased penile skin (n = 3); (II) excess abdominal skin and fat (n = 6); (III) excess skin and fat with diseased penile skin (n = 16); and (IV) type III plus severe scrotal edema (n = 2). Surgical treatment (eg, excision and grafting, mons suspension, panniculectomy, translocation of testes, and/or scrotectomy) was tailored based on classification. Complications included wound breakdown (n = 3), cellulitis (n = 4), and hematoma (n = 1). Nearly all patients (96%) reported early satisfaction and improvement in their symptoms postoperatively. CONCLUSIONS: Classifying patients with buried penis according to preoperative examination findings may guide surgical decision-making and preoperative counseling and allow for optimized aesthetics to enhance self-esteem and sexual well-being.

Neuroma Implantation into Long Bones: Clinical Foundation for a Novel Osseointegrated Peripheral Nerve Interface.

Symptomatic neuroma after major extremity amputation is a challenging clinical problem for which there are many described treatment options. Neuroma excision and implantation into the medullary canal of long bones offers durability and insulation, and minimizes chronic pain. Another challenge in amputees is impaired function and an ongoing need for accessible and functional prostheses that are "bidirectional," in that they provide both fine motor control and sensory feedback. Drawing on clinical experience with neuroma implantation into the medullary canal of long bones, the authors propose a novel neural interface whereby a terminal nerve end is redirected into the medullary canal of a nearby long bone and interfaced with an electrode array. The osseointegrated neural interface aims to exploit electrical signals from peripheral nerves to control advanced prosthetic devices for amputees. The purpose of this article is to present 2 clinical cases of nerve translocation into bone that serve as the clinical foundation of the osseointegrated neural interface as an innovative interface for prosthetic control.

A Muscular Etiology for Medial Implant Malposition Following Subpectoral Augmentation.

BACKGROUND: Implant malposition is becoming an increasingly recognized complication following subpectoral breast augmentation. Although several causes of medial malposition have been previously demonstrated, medial implant malposition secondary to unintended pectoralis muscle slips has not been previously described. OBJECTIVE: The goal of this study is to describe a form of medial implant malposition caused by pectoralis major and minor musculature vectors on the implant. METHODS: The primary investigator performed a retrospective review of all patients who underwent revisional breast surgery for the diagnosis of symmastia or medial implant malposition following subpectoral augmentation. Those patients with muscular-type etiology for medial implant malposition were identified. RESULTS: Five patients with pectoralis muscle slips causing medial implant malposition were identified. The pectoralis muscle slips were successfully diagnosed on preoperative exam and corrected with specific surgical procedures aimed at balancing surrounding forces and thus correcting malposition. CONCLUSIONS: Pectoralis muscle slips contributing to medial malposition can be found in some patients after subpectoral breast augmentation. The etiology of this deformity is unknown, but theorized to be caused by anatomic predisposition, with slips inadvertently formed during subpectoral pocket formation arising from the pectoralis minor and/or incompletely released or accessory pectoralis major muscles.