Kai Yuen Wong

Molecular mechanisms underlying bile acid‐stimulated glucagon‐like peptide‐1 secretion

BACKGROUND AND PURPOSE The glucagon‐like peptides GLP‐1 and GLP‐2 are secreted from enteroendocrine L‐cells following nutrient ingestion. Drugs that increase activity of the GLP‐1 axis are highly successful therapies for type 2 diabetes, and boosting L‐cell secretion is a potential strategy for future diabetes treatment. The aim of the present study was to further our understanding of the bile acid receptor GPBA (TGR5), an L‐cell target currently under therapeutic exploration.

“Emergency” definitive reconstruction of a necrotising fasciitis thigh debridement defect with a pedicled TRAM flap

INTRODUCTION Necrotising fasciitis (NF) is a rare, severe, rapidly progressing and life-threatening synergistic infection primarily affecting the superficial fascia. A novel method of definitive and aesthetic reconstruction of NF thigh defects by using a pedicled transverse rectus abdominis myocutaneous (TRAM) flap without recourse to temporising skin grafts is presented. PRESENTATION OF CASE A 30-year-old parous woman presented in extremis with fulminant NF of her left anteromedial thigh. Following emergency radical debridement and intensive care stabilisation she was reconstructed 48h later in a single stage with a pedicled TRAM flap islanded on the ipsilateral deep inferior epigastric vessels. There was excellent contour restoration of her thigh and coverage of the exposed femoral vessels. DISCUSSION Pedicled flaps based on the rectus abdominis muscle provide a large, readily available reconstructive option for correction of substantial regional defects as herein illustrated. They are robust when based on dominant inferior vascular pedicle with a long reach and wide arc of rotation when designed transversely (as a TRAM flap). CONCLUSION This case also illustrates that definitive flap reconstruction of NF can be successfully undertaken in the emergent setting, thereby negating the need for large areas of skin grafting which can lead to contractures with consequent functional impairment and suboptimal aesthetic results.

Conventional versus ultrasound-assisted liposuction in gynaecomastia surgery: a 13-year review.

BACKGROUND Numerous surgical techniques exist for gynaecomastia treatment. Although ultrasound-assisted liposuction (UAL) is thought to be more effective than conventional liposuction, to date there remains no objective and direct comparison of the two modalities. Hence, a comparative study was performed of a single surgeons experience over 13 years using two definitive parameters, namely intraoperative conversion to open excision and postoperative revisional surgery rates. METHODS All gynaecomastia patients treated with UAL or conventional liposuction (1999-2012) were retrospectively studied. UAL was only available in the private sector and was used for all such patients with no other selection or exclusion criteria. RESULTS A total of 219 patients (384 breasts) with a mean age of 29 years (range 12-74) were evaluated. UAL was utilised in 24% of breasts (47 patients, 91 breasts). Compared with conventional liposuction, UAL had significantly lower rates of intraoperative conversion to open excision (25% vs. 39%; p<0.05) and postoperative revision (2% vs. 19%; p<0.001) using Fishers exact test. The haematoma rate for each technique was 1%. CONCLUSION UAL is a more effective treatment modality for gynaecomastia than conventional liposuction as determined by intraoperative conversion to open surgery and subsequent need for revision.

Paediatric extravasation injuries: a review of 69 consecutive patients.

Extravasation injury occurs when fluid from an intravenous (IV) line leaks into the surrounding tissue spaces. It has the potential to cause significant long standing aesthetic and functional morbidity. Extravasation injury has a reported incidence of 0.1e6.5%, and is higher among the paediatric population [1]. The higher incidence in this age group, particularly in neonates is due to small fragile veins, IV lines required over long periods of time and the inability to communicate clearly [2]. The extent of damage following extravasation injury depends on the extravasate substance, site and amount. As most extravasation injuries remain localised and heal spontaneously with conservative management, the potential sequelae are often underestimated. The damage caused can lead to necrosis and soft tissue loss. Furthermore, scarring can lead to contractures and deformity. Severe extravasation injuries may result in largewounds requiring surgical intervention such as debridement, reconstruction and even limb amputation [3]. There are currently no national guidelines on the management of extravasation injuries in the United Kingdom. We review the literature on extravasation injuries and present the management outcomes at a single tertiary hospital. All patients under the age of 18 who had extravasation injuries between 2011 and 2012 were retrospectively studied. Outcomes were correlated with patient characteristics, management and timing of events. A total of 69 cases were identified, of which 54% were female and the mean age was 36 months (range 1 daye18 years). The paediatric extravasation injury rate was 0.2% of all paediatric hospital admissions with the majority associated with prematurity (Table 1). The site of injury was upper limb in 65% of cases (40% on the dorsum of hand), 25% lower limb and 10% other locations. Average time from injury to review by the plastic surgery team was 4 h (range 0.2e24) and the average inpatient follow up was 3 days (range 1e21). Of all the substances extravasated, 32% were maintenance fluids (NaCl, glucose, KCl), 23% total parenteral nutrition and 45% others. Overall, 62% of cases were washed out and none of these developed complications. Therewere 5 significant complications including 3 cases of associated infection, 1 case of ischaemic toe with subsequent digit amputation and 1 case of calcinosis cutis (Fig. 1). The latter case involved prolonged hospitalisation and readmission for secondary infection. There was no statistical difference in age or the average time from injury to review by the plastic surgery team between complicated and non-complicated cases. However, all cases with

Opportunistic internal mammary lymph node biopsy during microvascular free flap breast reconstruction: A useful technique?

Internal mammary lymph node (IMLN) biopsy for staging breast cancer is not standard practice. The significance of IMLNs encountered incidentally during dissection of internal mammary vessels (IMVs) for microvascular free flap breast reconstruction (FFBR) remains obscure. Since our last study,1 we now routinely harvest incidental IMLNs during FFBR. We present our 15-year experience with the opportunistic harvest of IMLNs during FFBR. All IMV anastomoses performed between 1997 and 2011 for delayed (DBR) or immediate breast reconstruction (IBR) at Addenbrooke’s University Hospital, Cambridge were identified from our audit database. All IMLN harvests were analysed from our histology database by retrospectively correlating them with patient and tumour characteristics and oncological outcomes. Patients with breast tumours that were large (T3), locally advanced (T4) or had involvement of more than four axillary lymph nodes underwent preoperative staging. This was performed with CT chest, abdomen and pelvis with bone windows to include the upper femurs. Axillary staging prior to 2006 involved level 2 axillary lymph node dissection for invasive cancers and since then, sentinel lymph node biopsy has been used. A total of 503 FFBRs were performed in 474 patients. Of these, 86 patients (18%) had 95 IMLNs harvested during 54 immediate and 41 delayed FFBRs. Eleven patients (13%) had tumour-positive nodes (Table 1, Fig. 1). In the IBR group, 7 of 44 patients were confirmed to have IMLN metastases histologically (16%) compared to 4 of 42 patients (10%) in the DBR group. The mean patient agewas 47 years with no significant age difference between the IBR and DBR groups. Therewere also no significantmacroscopic differences between the metastatic and non-involved nodes. In the DBR group, the median time between mastectomy and reconstruction was 30 months (range 11–154). All patients with positive IMLNs were offered chemotherapy and eight received radiotherapy to the internal mammary chain. Three of the seven IMLN positive IBR patients (43%) have died of

Membrane potentials in Rana temporaria muscle fibres in strongly hypertonic solutions

Conventional microelectrode methods were used to measure variations in resting membrane potentials, Em, of intact amphibian skeletal muscle fibres over a wide range of increased extracellular tonicities produced by inclusion of varying extracellular concentrations of sucrose. Moderate increases in extracellular tonicity to up to 2.6× normal (2.6τ) under Cl− free conditions produced negative shifts in Em that followed expectations for the K+ Nernst equation (EK) applied to a perfect osmometer containing a conserved intracellular K+ content despite any accompanying cell volume change. In contrast, Em remained stable in fibres studied in otherwise similar Cl− containing solutions, consistent with Em stabilization despite negative shifts in EK through inward cation-Cl− co-transport activity. Short exposures to higher tonicities (>3τ) similarly produced negative shifts in Em in Cl− free but not Cl− containing solutions. However, prolonged exposures to solutions of >3τ caused gradual net positive changes in Em in both Cl− containing and Cl− free solutions suggesting that these changes were independent of cation-Cl− transport. Indeed, there was no evidence of cation-Cl− co-transport activity in strongly hypertonic solutions despite its predicted energetic favourability, suggesting its possible regulation by Em in muscle. Additional findings implicated a failure to maintain greatly increased transmembrane [K+] gradients in these Em changes. Thus: (1) halving or doubling [K+]e produced negative or positive shifts␣in Em, respectively in isotonic or moderately hypertonic (<2.7τ), but not strongly hypertonic (>3τ) solutions; (2) subsequent restoration of isotonic extracellular conditions produced further positive changes in Em consistent with a dilution of the depleted [K+]i by fibres regaining their original resting volumes; (3) quantitative modelling similarly predicted a gradual net efflux of K+ as the balance between active and passive [K+] fluxes altered due to increased transmembrane [K+] gradients in hypertonic and low [K+]e solutions. However, the observed positive changes in Em in the most strongly hypertonic solutions eventually exceeded these predictions suggesting additional limitations on␣Na+/K+-ATPase activity in strongly hypertonic solutions.

Are non-melanoma skin cancer incomplete excision rates different between grades of plastic surgeons?

Non-melanoma skin cancers (NMSCs) are increasing in incidence and worldwide there are currently 2e3 million new cases each year. In the majority of departments, local anaesthetic (LA) day case NMSC surgery is undertaken by all grades of surgeon and is considered a valuable training opportunity. When NMSC excision margins are involved, the recommendation is usually for re-excision, radiotherapy or close outpatient follow-up. All of these have a negative effect on patient experience and incur additional financial costs. In an era where demand is increasing on limited resources and risk-adjusted clinical performance data is used to allocate funding to departments and trusts, significant differences in incomplete excision rates between grades of surgeons may have a significant bearing on future skin cancer service provision. We retrospectively compared NMSC incomplete excision rates of consultants versus trainees for procedures performed in the outpatient clinic setting under LA.

Reconstruction of chest wall chondrosarcoma with an anterolateral thigh free flap: An illustration of decision-making in chest wall reconstruction

INTRODUCTION Chondrosarcomas are the most common primary chest wall malignancy. The mainstay of treatment is radical resection, which often requires chest wall reconstruction. This presents numerous challenges and more extensive defects mandate the use of microvascular free flaps. Selecting the most appropriate flap is important to the outcome of the surgery. PRESENTATION OF CASE A 71-year-old male presented with a large chondrocarcoma of the chest wall. The planned resection excluded use of the ipsilateral and contralateral pectoralis major flap because of size and reach limitations. The latissimus dorsi flap was deemed inappropriate on logistical grounds as well as potential vascular compromise. The patient was too thin for reconstruction using an abdominal flap. Therefore, following radical tumour resection, the defect was reconstructed with a methyl methacrylate polypropylene mesh plate for chest wall stability and an anterolateral thigh free flap in a single-stage joint cardiothoracic and plastic surgical procedure. The flap was anastomosed to the contralateral internal mammary vessels as the ipsilateral mammary vessels had been resected. DISCUSSION The outcome was complete resection of the tumour, no significant impact on ventilation and acceptable cosmesis. CONCLUSION This case demonstrates the complex decision making process required in chest wall reconstruction and the versatility of the ALT free flap. The ALT free flap ensured adequate skin cover, subsequent bulk, provided an excellent operative position, produced little loss of donor site function, and provided an acceptable cosmetic result.

Subungual squamous cell carcinoma

Subungual squamous cell carcinoma (SCC) is rare. We present a case of subungual SCC with invasion into the underlying bone and review the literature.

Gluteal fold flap in perineal reconstruction for Crohn's disease-associated fistulae

INTRODUCTION Crohns disease is increasing in incidence worldwide. It is associated with many complications including fistulae, which may require surgical intervention. Occasionally, formal perineal reconstruction is needed for extensive or definitive fistula surgery. Reconstruction for inflammatory disease presents unique challenges and often calls for innovative solutions. Gluteal fold flaps (GFFs), which have been widely used in vulvo-vaginal malignancy and anorectal cancer surgery, have not hitherto been reported for Crohns disease-associated fistulae. CASE PRESENTATION A 30-year-old female presented with a 5-year history of Crohns-associated perianal and rectovaginal fistulae. She had a previous small bowel resection and ileostomy. A laparascopic pan-proctocolectomy was carried out followed by perineal reconstruction in a single stage procedure using a pedicled fasciocutaneous GFF. Seven months postoperatively, revisional surgery was carried out using the contralateral GFF due to two areas of persistent wound dehiscence. The outcome was complete resolution of the fistulae, stable wound closure and good cosmesis. DISCUSSION & CONCLUSION This case demonstrates that it is practical to use the GFF for perineal reconstruction following excision of complex Crohns-associated fistulae. The flap avoids the sequelae associated with sacrifice of regional muscle flaps and specifically circumvents the unavailability of the rectus abdominis flap in slim patients or those with in-situ ileostomies. It is easy and quick to raise and does not require an intra-operative change in the patients position. The GFF ensured well vascularised skin cover, adequate flap volume with no loss of function and low donor site morbidity.