High-Fidelity Perforator Visualization for Cadaver Dissection in Surgical Training.

In the first half of the third century B.C., Herophilus and Erasistratus performed the first systematic dissection of the human body. For subsequent centuries, these cadaveric dissections were key to the advancement of anatomical knowledge and surgical techniques. To this day, despite various instructional methods, cadaver dissection remained the best way for surgical training. To improve the quality of education and research through cadaveric dissection, our institution has developed a unique method of perforator-preserving cadaver injection, allowing us to achieve high-fidelity perforator visualization for dissection studies, at low cost and high efficacy. Ten full body cadavers were sectioned through the base of neck, bilateral shoulder, and hip joints. The key was to dissect multiple perfusing arteries and draining veins for each section, to increase "capture" of vascular territories. The vessels were carefully flushed, insufflated, and then filled with latex dye. Our injection dye comprised of liquid latex, formalin, and acrylic paint in the ratio of 1:2:1. Different endpoints were used to assess adequacy of injection, such as reconstitution of eyeball volume, skin turgor, visible dye in subcutaneous veins, and seepage of dye through stab incisions in digital pulps. Dissections demonstrated the effectiveness of the dye, outlining even the small osseous perforators of the medial femoral condyle flap and subconjunctival plexuses. Our technique emphasized atraumatic preparation, recreation of luminal space through insufflation, and finally careful injection of latex dye with adequate curing. This has allowed high-fidelity perforator visualization for dissection studies.

Infection of a venous port - beware of the Mycobacterium.

An 84-year-old female with metastatic left breast cancer underwent a venous port insertion for chemotherapy. The port was inserted using standard techniques with image guidance under local anesthesia. She presented after 36 days with evidence of infection. A limited bedside ultrasound demonstrated free fluid surrounding the port. The port was subsequently removed the same day, at which time pus was expressed from the subcutaneous pocket. The culture from the pus grew Mycobacterium abscessus. She required removal of the port and wound debridement, wound dressings and a prolonged course of antibiotics. Mycobacterium abscessus is a group of rapidly growing, multidrug-resistant, non-tuberculous mycobacteria that are also relatively resistant to standard skin disinfectants. In recent years, this organism has been increasingly reported as the culprit in post-operative or post-procedural infections. Treatment is challenging due to multidrug resistance, and requires an extensive course of intravenous antimicrobial and macrolide-based combination therapy followed by oral antimicrobial therapy. Early treatment is essential as progression may result in disseminated infection. We discuss the peri-operative and post-operative care required in preventing and treating infection with this organism.

Customized Two-Dimensional Computed Tomography-Guided Preoperative Pectus Bar Shaping.

INTRODUCTION: Successful minimally invasive repair of pectus excavatum relies on a pectus bar that closely conforms to the desired shape of the sternum and ribs to produce optimal elevation and remodeling. However, the present method of empirical intraoperative bar shaping is tedious and risks trauma to surrounding structures. To overcome this, we devised a technique using a life-sized computed tomography (CT) printout of the patient's chest wall to guide preoperative bar bending. METHODS: A 5-cm-wide polymethylmethacrylate block placed on the sternum as the patient underwent chest CT was used as a marker to guide scaling of an axial screenshot of the patient's chest to life-size. This life-size image was printed and the planned correction of the patient's chest wall was traced onto it. The pectus bar was bent according to this template. Patient demographics, Haller index, surgical indications, operative technique, complications, aesthetic and functional improvements, and overall satisfaction were assessed. RESULTS: Thirty patients (4 women) underwent primary minimally invasive repair of pectus excavatum with a single pectus bar shaped preoperatively over an 8-year period. The average age and Haller index was 20.6 years and 5.4, respectively. The mean operative time was 66.4 minutes. Satisfactory sternal elevation was attained with a single attempt at bar insertion in all cases. Two patients had pneumothoraxes that resolved without intervention. The mean follow-up period was 50.1 months. There were no cases of bar migration or recurrence of deformity after bar removal. On a 5-point Likert scale, all patients indicated an improvement in aesthetic appearance (4.6), and patients with physical symptoms (10) reported an improvement in function (4.4). The overall satisfaction score was 4.7. CONCLUSIONS: This technique of CT-guided preoperative pectus bar shaping is straightforward, eliminates the need for intraoperative revisions to bar shape, and achieves effective correction of the pectus excavatum deformity. All patients were satisfied with the aesthetic, functional, and overall outcomes.

Early Experience with Biobranetm for Definitive Coverage of Tangentially Excised Partial-Thickness Thermal Burns.

BiobraneTM is a popular biosynthetic semi-permeable skin substitute conventionally applied onto non-excised partial thickness burn wounds to facilitate healing. The use of BiobraneTM for definitive coverage after excision of partial-thickness thermal burns has not been reported. We highlighted our experience of immediate BiobraneTM application for definitive coverage of tangentially-excised partial thickness thermal burn wounds in four patients. This technique is safe and efficient, minimizes painful and costly dressing changes, avoids the complications associated with autologous skin grafting, and eliminates the unpredictability of burns wound conversion. We believe this method expands the indications for BiobraneTM usage, accelerates wound healing, and provides better aesthetic outcomes.

Anatomical Study of the Medialis Pedis Flap and its clinical applications in Asian Singaporean Patients.

PURPOSE: The purpose of this study was to revisit the medial plantar artery's anatomy and study its distribution for raising the medialis pedis flap. Several investigators have reported their clinical experience with the use of this flap for reconstruction of soft tissue defects of the hand. However, many have reported difficulty raising the flap due to variations in its arterial anatomy and the confusion that exists with respect to the nomenclature in our literature. METHODS: This study was divided into 2 parts: an anatomic study and clinical application. In the anatomic study, 12 cadaveric feet specimens from 6 patients were injected with latex and barium-gelatin injections and the medial branch of the deep division of the medial plantar artery distribution was studied. We then described the use of a medialis pedis flap in four clinical cases to cover defects of the digits. RESULTS: The anatomic study revealed that the average pedicle length of the deep division of the medial plantar artery was 1.94cm. In the four illustrative clinical cases where the flap was used, the average flap size was 4.5 × 3.75cm. Donor sites were either closed primarily or with skin grafts. The vessels used for this flap were the medial branch of the deep division of the medial plantar artery and venae commitantes, or subcutaneous veins which provided the superficial drainage. All flaps were successful without any significant complications. The study is novel in that it describes the anatomic variability of length of the medial branch of the deep division of the medial plantar artery that exits in nature. CONCLUSIONS: This paper describes the medial branch of the deep division of the medial plantar artery and the anatomic variations that exist in the raising of the medialis pedis flap. We have shown how a medialis pedis flap is an ideal option for reconstructing soft tissue defects of the hand because of its texture, bulkiness and pliability in the context of like for like reconstruction.

Hepatic Artery Reconstruction in Living Donor Liver Transplantation With the Radial Artery Interpositional Graft.

INTRODUCTION: Reconstitution of hepatic artery inflow is essential for a successful liver transplantation. Living donor transplantation presents additional challenges in the form of a short and small donor vessel stump, exacerbating the poor surgical access for microsurgery. Few reports have described the use of the radial artery as an interposition graft in liver transplantation; we present a series of 6 cases and discuss the technical merits of this procedure. METHODS: Retrospective review of consecutive patients undergoing living donor liver transplantation from December 2015 to December 2019 was performed. Demographics, operative details, and postoperative outcomes were reviewed. RESULTS: Twenty-two patients underwent living donor liver transplantation. Radial artery interposition grafting was used in 6 cases, including 1 salvage case for hepatic artery thrombosis. One patient developed hepatic artery stenosis (2 weeks postoperatively) that was conservatively managed. After radial artery grafting, all patients had normal resistive indices on duplex ultrasonography at up to 20 months postoperatively. The mean follow-up was 15.2 months. CONCLUSION: When faced with a significantly short vessel stump or caliber mismatch, radial artery interpositional grafting is a safe and useful technique for reducing tension and overcoming vessel size mismatch in hepatic artery reconstruction.

Coverage of anterior mediastinal tracheostomy with bipedicled anterolateral thigh flap.

BACKGROUND: Cancer defects requiring anterior mediastinal tracheostomy (AMT) are complex, often accompanied by tracheo-laryngeal and pharyngeal defects with exposure of the great vessels and mediastinal cavity. The trachea has to be mobilised and exteriorised as an end-tracheostome through the anterior chest. A well-vascularised flap that can resurface skin defects, obliterate dead space and allow maturation of a reliable anterior mediastinal tracheostome is required. We describe a modification of using a centrally fenestrated bipedicled chimeric anterolateral thigh flap (ALT) to address these challenges. METHODS: A free chimeric bipedicled ALT flap was designed. The skin defect was resurfaced by a vertically-oriented skin paddle. Two chimeric muscle components were used to partition the mediastinum and the great vessels of the neck from the tracheostome. The mediastinal trachea was mobilised and matured through a centrally-fenestrated opening in the flap. Layered fascial sutures were employed to minimize dehiscence. RESULTS/COMPLICATIONS: Two patients with AMT underwent the modified ALT. No major complications such as flap-tracheostomy dehiscence occurred. One patient had a small peripheral demarcation of the flap which required revision and secondary closure. CONCLUSION: The bipedicled design of the modified ALT flap provided robust blood supply to the central fenestration through dual perforators, avoiding flap-tracheostomy separation. The chimeric muscle components obliterate dead space and protect the great vessels of the neck and mediastinum. The thin pliable nature of the anterolateral thigh skin also allowed for tensionless inset of the trachea.

Impact of Microsurgical Anastomosis of Hepatic Artery on Arterial Complications and Survival Outcomes After Liver Transplantation.

Hepatic artery (HA) complications after liver transplant (LT) can lead to biliary complications, graft failure, and mortality. Although microsurgery has been established to improve anastomotic outcomes, it prolongs surgical time and has not reached widespread adoption at all transplant centers. We investigated the incidences of arterial, biliary complications and outcomes after using microsurgery to anastomose HA during LT. Retrospective cohort of consecutive LT performed from 2006 to 2018 was reviewed for operative details and postoperative outcomes. Cox-regression models were used to investigate the relationship between variables and outcomes. Eighty (62.5%) LTs (Group 1) were performed without and compared with 48 (Group 2) with microsurgical anastomosis of HA. Both groups were comparable in terms of arterial and biliary anastomoses performed. Incidence of early HA thrombosis was similar (6.2% vs 2.1%, P = .28). Group 2 had lower incidence of short- and long-term arterial complications, especially amongst living donor liver transplantations (LDLT) (5.3% vs 35.0%, P = .022). On multivariate analysis, microsurgery was associated with lower risk (hazard ratio [HR] 0.09, 95% confidence interval [CI] 0.01-0.71) of, and LDLT had higher risk (HR 4.23, 95% CI 1.46-12.27) of arterial complications. Biliary complications were associated with LDLT (HR 3.91, 95% CI 1.30-11.71) and dual biliary anastomoses (HR 5.26, 95% CI 1.15-24.08) but not with occurrence of HA complications. Worse patient survival was associated with the occurrence of any HA complication (HR 4.11, 95% CI 1.78-9.48). Hepatic arterial complications can be reduced using microsurgical techniques for the anastomosis, resulting in improved patient survival outcomes after liver transplantation.

Current operative management and therapeutic algorithm of lymphedema in the lower extremities.

Lymphedema is defined as the abnormal accumulation of interstitial fluid in subcutaneous tissues resulting from cancer, cancer treatment (surgery and/or radiotherapy), infection, inflammatory disorders, obesity, and hereditary syndromes. Surgical management of lymphedema can be broadly classified into two categories, reductive surgical techniques such as direct excision, suction assisted protein lipectomy (SAPL) or radical reduction with perforator preservation (RRPP); and physiological surgical procedures such as lymphaticovenous anastomosis (LVA) and vascularised lymph node transfer (VLNT). These techniques and their various combinations were evaluated. The results revealed patients with reversible lymphedema (ISL stage I, mild severity) benefit most from physiological procedures (LVA or VLNT) which can reduce the chance of disease progression to the chronic, solid phase. Reductive techniques such as SAPL, RPPP, or direct excision procedures should be reserved for patients with advanced - severe lymphedema (ISL stages II and especially stage III) as the surgical treatment of choice. In this study, current literature on the surgical treatment of lower extremity lymphedema is reviewed and discussed in conjunction with authors' clinical experiences. An algorithm is presented, based on clinical evidence and experience which aims to provide a structured approach to managing lower limb lymphedema.

The use of negative-pressure wound therapy over a cultured epithelial autograft for full-thickness wounds secondary to purpura fulminans in an infant.

Purpura fulminans is a serious condition that can result in severe morbidity in the pediatric population. Although autologous skin grafts remain the gold standard for the coverage of partial- to full-thickness wounds, they have several limitations in pediatric patients, including the lack of planar donor sites, the risk of hemodynamic instability, and the limited graft thickness. In Singapore, an in-house skin culture laboratory has been available since 2005 for the use of cultured epithelial autografts (CEAs), especially in burn wounds. However, due to the fragility of CEAs, negative-pressure wound therapy (NPWT) dressings have been rarely used with CEAs. With several modifications, we report a successful case of NPWT applied over a CEA in an infant who sustained 30% total body surface area full-thickness wounds over the anterior abdomen, flank, and upper thigh secondary to purpura fulminans. We also describe the advantages of using NPWT dressing over a CEA, particularly in pediatric patients.

Evaluating the feasibility of a novel Marking Breast Oncoplastic Surgery Simulator (MBOSS) as a training tool for marking: a randomised trial.

BACKGROUND: Currently, volunteers and/or anatomical models are used for teaching oncoplastic surgery marking. However, as the breast is an intimate organ, recruiting volunteers is difficult, and the available droopy breast models have limitations. We evaluated the feasibility of a novel Marking Breast Oncoplastic Surgery Simulator (MBOSS) for the teaching of marking. METHODS: Breast/plastic surgeons/trainees, grouped according to their oncoplastic experience, were randomized to MBOSS or volunteer. All had a pre-test evaluation prior to receiving hands-on training in inverted T mammoplasty marking in their randomized group, followed by an assessment of their marking skills, by an examiner blinded to their group assignment. All participants then underwent post-test and course evaluations, and those who used MBOSS for training, also evaluated MBOSS realism. Learning outcomes between the two groups were compared using the Kirkpatrick educational model. RESULTS: Forty participants were enrolled. Demographics, baseline oncoplastic experience and pre-test results were comparable between the MBOSS and volunteer groups. For Kirkpatrick level 1 satisfaction outcomes, the two groups did not differ significantly. For level 2 knowledge assessment, MBOSS post-test scores were significantly higher (P=0.0471). For level 3 skill application and level 4 organizational impact evaluated 6 months post course, there were no significant differences between the groups. Although MBOSS may not mimic the breast completely, 95% of MBOSS-trained participants rated MBOSS as a good training tool and 85% would use MBOSS instead of a volunteer. CONCLUSIONS: MBOSS learning outcomes are comparable to outcomes using volunteers, making MBOSS an alternative for teaching oncoplastic surgery marking.

Early Initiation of Renal Replacement Therapy Among Burned Patients With Acute Kidney Injury.

BACKGROUND: Burned patients with acute kidney injury (AKI) requiring renal replacement therapy (RRT) have exceedingly high mortality rates of 73% to 100%. Since January 2011, we have been adopting an early RRT approach in managing burned patients with AKI. Our hypothesis was that early initiation of RRT leads to improved outcome and survival among burned patients with AKI. METHODOLOGY: We conducted a retrospective analysis of Burns Database in Singapore General Hospital from January 2011 to February 2016. Indications for dialysis included serum creatinine of greater than 1.5 times baseline or urine output of less than 0.5 mL/kg per hour for at least 6 consecutive hours. Patients with similar condition from January 2006 to December 2010 were recruited for comparison. RESULT: A total of 27 patients with burns and AKI were recruited from January 2011 to February 2016. The mean age was 45.4 years and 88.9% were male. The mean total burn surface area (TBSA) was 54.8%. The total volume of fluid resuscitation was 2.7 mL/kg per TBSA. The time from onset of burn to RRT was 6.4 days. Most patients presented with stage 1 AKI (51.9%), whereas 22.2% and 25.9% had stage 2 and stage 3 AKI, respectively. Most patients (74.1%) received CRRT and 18.5% received SLED. The mortality rate was 37.0% with majority of death (70%) due to sepsis/multiorgan failure. Only 1 patient required long-term RRT after discharge, and there was no occurrence of abdominal compartment syndrome. The mean age of 15 patients from 2006 to 2010 was 47.8 years. The mean TBSA was 49.5%. Only 26.7% of patients were started on RRT. The mortality rate was 66.7%, which was higher than that of subjects from 2011 to 2016 (37.0%) (P = 0.039). CONCLUSIONS: Optimal timing of RRT for burned patients with AKI has not been established and data on early RRT approach are scarce. The findings of our study suggested that early RRT was associated with lower mortality rates among burned victims with AKI.

Trachea Reconstruction with Single-Stage Composite Flaps in a Rabbit Model.

BACKGROUND: Trachea reconstruction requires creation of a functional lining, semirigid support, and vascularity. We aimed to design composite flaps with these three components in a rabbit model. METHODS: Circumferential (n = 9) and partial anterior (n = 8) tracheal defects were created in rabbits. A circumferential defect was reconstructed with a tubed ear flap incorporating cartilage for support and skin for lining. This was pedicled on the posterior auricular vessels and tunneled into the neck to bridge the defect. In the second experiment, a longitudinal anterior trachea defect was patched with a pedicled rib cartilage and intercostal muscle flap based on the internal mammary vessels. The vascularized fascia over the intercostal muscles replaced the lining while the cartilage provided support. Postoperatively, the rabbits were monitored clinically and endoscopically. The tracheal constructs were examined histologically after the animals were sacrificed. RESULTS: Rabbits with circumferential defects reconstructed with the ear flap survived up to 6 months. Histology demonstrated vascularized cartilage with good integration of the flap with native trachea. However, hair growth and skin desquamation resulted in airway obstruction in the long term. In the second experiment, all the rabbits survived without respiratory distress, and the intercostal muscle fascia was completely covered by native respiratory epithelium. CONCLUSION: We described two experimental techniques using autologous composite flaps for single-stage trachea reconstruction in a rabbit model. Skin was a poor lining replacement, whereas vascularized muscle fascia became covered with respiratory epithelium. A rib cartilage and muscle flap could potentially be used for reconstruction of partial defects in humans.

Use of the cross-leg distally based sural artery flap for the reconstruction of complex lower extremity defects.

Cross-leg flaps are a useful reconstructive option for complex lower limb defects when free flaps cannot be performed owing to vessel damage. We describe the use of the extended distally based sural artery flap in a cross-leg fashion for lower extremity coverage in three patients. To maximise the viability of these extended flaps, a delay was performed by raising them in a bipedicled fashion before gradual division of the tip over 5 to 7 days for cross-leg transfer. Rigid coupling of the lower limbs with external fixators was critical in preventing flap avulsion and to promote neovascular takeover. The pedicle was gradually divided over the ensuing 7 to 14 days before full flap inset and removal of the external fixators. In all three patients, the flaps survived with no complications and successful coverage of the critical defect was achieved. One patient developed a grade 2 pressure injury on his heel that resolved with conservative dressings. The donor sites and external fixator pin wounds healed well, with no functional morbidity. The cross-leg extended distally based sural artery flap is a reliable reconstructive option in challenging scenarios. Adequate flap delay, manoeuvres to reduce congestion, and postoperative rigid immobilization are key to a successful outcome.

Gracilis pull-through flap for the repair of a recalcitrant recto-vaginal fistula.

Recto-vaginal fistulas are difficult to treat due to their high recurrence rate. Currently, no single surgical intervention is universally regarded as the best treatment option for rectovaginal fistulas. We present a case of recurrent recto-vaginal fistula surgically treated with a gracilis pull-through flap. The surgical goals in this patient were complete excision of the recto-vaginal fistula and introduction of fresh, vascularized muscle to seal the fistula. A defunctioning colostomy was performed 1 month prior to the present procedure. The gracilis muscle and tendon were mobilized, pulled through the freshened recto-vaginal fistula, passed through the anus, and anchored externally. Excess muscle and tendon were trimmed 1 week after the procedure. Follow-up at 4 weeks demonstrated complete mucosal coverage over an intact gracilis muscle, and no leakage. At 8 weeks post-procedure, the patient resumed sexual intercourse with no dyspareunia. At 6 months post-procedure, her stoma was closed. The patient reported transient fecal staining of her vagina after stoma reversal, which resolved with conservative treatment. The fistula had not recurred at 20 months post-procedure. The gracilis pull-through flap is a reliable technique for a scarred vagina with an attenuated rectovaginal septum. It can function as a well-vascularized tissue plug to promote healing.

Comparison of Outcomes of Fasciocutaneous Free Flaps and Jejunal Free Flaps in Pharyngolaryngoesophageal Reconstruction: A Systematic Review and Meta-Analysis.

BACKGROUND: The literature reports a wide variety of reconstructive methods for pharyngolaryngoesophageal (PLO) defects, the most widely used being anterolateral thigh (ALT), radial forearm (RFF), and jejunal free flaps (JFF). However, there is a lack of uniform agreement among head and neck surgeons as to which technique offers the best results. With an increasing number of salvage PLO extirpations, determining the role of radiotherapy in influencing postoperative complication rates is becoming ever more important. Hence, this study aims to provide an up-to-date comparison of surgical and functional outcomes of the fasciocutaneous ALT and RFF versus the intestinal JFF for circumferential and partial PLO defects and determine whether radiotherapy, both preoperative and postoperative, influences the postoperative fistula and stricture rates in circumferential defects. METHODS: A systematic review and meta-analysis were performed using PubMed for reports published in the most recent 10 years between 2007 and 2017. RESULTS: A total of 33 articles comprising 1213 patients were reviewed. For circumferential defects, fistula and stricture rates were significantly lower in JFF than ALT and RFF. Of note, there was no statistical difference in tracheoesophageal speech and oral alimentation rates between JFF and the FC flaps. For near-circumferential and partial defects, ALT has a significantly lower fistula rate than RFF. There was no statistical difference in stricture and oral alimentation rates between ALT and RFF [corrected]. Fistula rates were significantly higher in patients who had preoperative radiotherapy than those without. However, there was no significant difference in fistula and stricture rates for postoperative radiotherapy. CONCLUSIONS: Jejunal free flaps still remain an excellent first choice for PLO reconstruction of circumferential defects. For near-circumferential and partial defects, ALT seems to have a better performance than RFF. Preoperative radiotherapy was associated with an increased risk of fistula formation in circumferential PLO defects but not postoperative radiotherapy.

Surgical and oncological safety of nipple-sparing mastectomy in an Asian population.

BACKGROUND: Nipple-sparing mastectomy (NSM) allows for excellent postmastectomy reconstruction aesthetics and is used for both therapeutic and risk-reducing purposes. Reservations regarding the potential for locoregional recurrence and concerns about nipple-areolar complex (NAC) necrosis remain amongst many surgeons. We review the surgical and oncological outcomes after NSM in our institution. METHODS: All NSM cases at the National Cancer Centre Singapore and Singapore General Hospital between 2005 and 2015 were reviewed. Tumour characteristics, reconstruction methods, surgical and oncological outcomes are described. RESULTS: A total of 139 NSMs were performed for 130 patients. The median age was 46 years (range 21-66). The use of NSM increased from 2% of all breast reconstructions in 2005 to 37% in 2015. The majority (n = 119; 86%) were for cancer treatment and 20 (14%) for risk-reducing purposes. Among those performed for cancer, patients mainly had early stage breast cancer (n = 106, 89%). Autologous reconstruction (n = 111, 80%) was most common. Early complications requiring surgical intervention occurred in 24 (17%) NSMs, including 9 partial/complete flap loss and 2 complete NAC loss. Smoking, previous breast radiation and periareolar incision were all not associated with a higher re-intervention rate (p = 0.93, 0.41 and 0.91, respectively). Median follow-up was 43 months (range 5-145). Five patients (4%) developed local recurrence, including 2 NAC recurrences. The 2- and 5-year overall survival rate is 97 and 90%, respectively. CONCLUSION: NSM is an oncologically safe procedure in selected patients with acceptable low complication rates.

Dermatological conditions seen in renal transplant recipients in a Singapore tertiary hospital.

INTRODUCTION: Lifelong immunosuppression after renal transplant exerts effects on the recipients' skin, including skin infections, skin cancers and drug-induced skin disorders. Our study aimed to determine the epidemiology of skin conditions among renal transplant recipients in the largest tertiary hospital in Singapore. METHODS: We reviewed the medical records of kidney transplant recipients at Singapore General Hospital, Singapore, between 1 January 2003 and 31 December 2013. Among these patients, the clinical data of patients who sought skin consultations with either dermatologists or plastic surgeons within the hospital was captured. RESULTS: A total of 178 patients were included in our study. There were 88 (45.6%) skin infections, 23 (11.9%) drug-induced skin conditions, 9 (4.7%) skin cancers and 73 (37.8%) other skin conditions. Skin infection was the predominant reason for consultation, with viral warts (15%, n = 29) being the most common. Of the nine cases in our cohort with skin cancer, there were three cases of basal cell carcinoma, three cases of Bowen's disease, two cases of extramammary Paget's disease and one case of squamous cell carcinoma. Drug-induced skin conditions, mainly attributable to long-term steroids and cyclosporin use, were represented by acne (9.3%, n = 18) and sebaceous hyperplasia (2.6%, n = 5). CONCLUSION: Our study demonstrated the spectrum of skin conditions that can be expected after renal transplantation. We wish to highlight the importance of careful dermatological screening and long-term follow-up for these patients, in order to reduce post-transplant skin complications.

Large animal models for long-segment tracheal reconstruction: a systematic review.

BACKGROUND: The reconstruction of extensive tracheal defects is an unresolved problem. Despite decades of research, a reliable and practical substitute remains to be found. While there have been clinical reports of successful long-segment tracheal reconstruction, reproducibility and widespread applicability of these techniques have yet to be achieved. Large animals such as the dog, pig, sheep, and goat have comparable tracheal morphology and physiology to humans making them useful preclinical models to screen potential therapeutic strategies. MATERIALS AND METHODS: The literature was reviewed to identify large animal models commonly used for tracheal reconstruction. A systematic search of PubMed and EMBASE was performed for large animal studies reporting on the reconstruction of long-segment tracheal and carinal defects. Fifty-seven studies were identified for analysis. RESULTS: There is no standard large animal model available for tracheal research. In recent years, livestock species have gained favor over dogs as animal models in this field. The minimum requirements for successful tracheal replacement are rigidity, vascularity, and epithelial lining. Early attempts with synthetic prostheses were met with disappointing results. An autologous tracheal substitute is ideal but hindered by limited donor site availability and the lack of a dominant vascular pedicle for microsurgical reconstruction. Although tracheal allotransplantation enables like-for-like replacement, there are unresolved issues relating to graft vascularity, immunosuppression, and graft preservation. Tissue engineering holds great promise; however, the optimal combination of scaffold, cells, and culture conditions is still indeterminate. CONCLUSIONS: Despite impressive advances in tracheal reconstruction, a durable substitute for extended tracheal defects continues to be elusive.