Randomized clinical trial of cutting balloon angioplasty versus high-pressure balloon angioplasty in hemodialysis arteriovenous fistula stenoses resistant to conventional balloon angioplasty.

PURPOSE: To compare the efficacy and safety of cutting balloon angioplasty (CBA) versus high-pressure balloon angioplasty (HPBA) for the treatment of hemodialysis autogenous fistula stenoses resistant to conventional percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: In a prospective, randomized clinical trial involving patients with dysfunctional, stenotic hemodialysis arteriovenous fistulas (AVFs), patients were randomized to receive CBA or HPBA if conventional PTA had suboptimal results (ie, residual stenosis > 30%). A total of 516 patients consented to participate in the study from October 2008 to September 2011, 85% of whom (n = 439) had technically successful conventional PTA. The remaining 71 patients (mean age, 60 y; 49 men) with suboptimal PTA results were eventually randomized: 36 to the CBA arm and 35 to the HPBA arm. Primary and secondary target lesion patencies were determined by Kaplan-Meier analysis. RESULTS: Clinical success rates were 100% in both arms. Primary target lesion patency rates at 6 months were 66.4% and 39.9% for CBA and HPBA, respectively (P = .01). Secondary target lesion patency rates at 6 months were 96.5% for CBA and 80.0% for HPBA (P = .03). There was a single major complication of venous perforation following CBA. The 30-day mortality rate was 1.4%, with one non-procedure-related death in the HPBA group. CONCLUSIONS: Primary and secondary target lesion patency rates of CBA were statistically superior to those of HPBA following suboptimal conventional PTA. For AVF stenoses resistant to conventional PTA, CBA may be a better second-line treatment given its superior patency rates.

Challenges and lessons learned from NOTES cholecystectomy initial experience: a stepwise approach from the laboratory to clinical application.

BACKGROUND/PURPOSE: The initial idea behind natural orifice transluminal endoscopic surgery (NOTES) was that of an incisionless surgery. NOTES cholecystectomy is a good model of human ingenuity and technological advance. NOTES cholecystectomy in a human being was performed at our institution after extensive laboratory work in live pig models. In this process we gained helpful information related to NOTES cholecystectomy. METHODS: More than 250 cholecystectomies in pigs have been performed. From May 2007 to November 2008 a total of 10 and 6 transvaginal and transgastric human cholecystectomies, respectively, have been performed. RESULTS: The procedure was successful in all patients, with a mean operative time of 120 min. There were no intraoperative or postoperative complications. Patients recovered promptly after surgery and had minor postoperative pain. They were discharged on the second postoperative day. CONCLUSIONS: The advantages of laparoscopy appeared to be enhanced by this approach: patients had minor postoperative pain and minimal scarring. This stepwise experience in the cholecystectomy procedure is an important first step in the development of methods and devices to enable the evaluation of potential incisionless NOTES surgery. Additional research and comparison studies are needed for further improvement in order to provide NOTES procedures to a wider range of patients.

Necrotizing fasciitis.

OBJECTIVE: To describe the defining characteristics and treatment of necrotizing fasciitis (NF), emphasizing early diagnostic indications. QUALITY OF EVIDENCE: PubMed was searched using the terms necrotizing fasciitis and necrotizing soft tissue infections, paired with early diagnosis. Results were limited to human studies in English. Additional articles were obtained from references within articles. Evidence is levels II and III. MAIN MESSAGE: Necrotizing fasciitis is classified according to its microbiology (polymicrobial or monomicrobial), anatomy, and depth of infection. Polymicrobial NF mostly occurs in immunocompromised individuals. Monomicrobial NF is less common and affects healthy individuals who often have a history of trauma (usually minor). Patients with NF can present with symptoms of sepsis, systemic toxicity, or evidence of skin inflammation, with pain that is disproportional to the degree of inflammation. However, these are also present in less serious conditions. Hyperacute cases present with sepsis and quickly progress to multiorgan failure, while subacute cases remain indolent, with festering soft-tissue infection. Because the condition is rare with minimal specific signs, it is often misdiagnosed. If NF is suspected, histology of tissue specimens is necessary. Laboratory and radiologic tests can be useful in deciding which patients require surgical consultation. Once NF is diagnosed, next steps include early wound debridement, excision of nonviable tissue, and wide spectrum cover with intravenous antibiotics. CONCLUSION: Necrotizing fasciitis is an uncommon disease that results in gross morbidity and mortality if not treated in its early stages. At onset, however, it is difficult to differentiate from other superficial skin conditions such as cellulitis. Family physicians must have a high level of suspicion and low threshold for surgical referral when confronted with cases of pain, fever, and erythema.

Effectiveness of bariatric surgery in diabetes prevention in high-risk Asian individuals.

INTRODUCTION: Obesity is a key risk factor in the development of Type 2 diabetes mellitus (T2DM). Bariatric surgery causes a large amount of durable weight loss in those with clinically severe obesity. We reported the effect of weight loss via bariatric surgery on DM prevention in those at high risk of developing DM. METHODS: This was a retrospective cohort study of 44 patients with obesity (mean body mass index 43.8 kg/m2) and pre-DM who underwent bariatric surgery and were followed up for up to three years. We also reviewed a non-surgical cohort of patients with obesity and pre-DM seen at the weight management clinic. RESULTS: 91% of patients attained normal glycaemic status at one year after bariatric surgery. At the three-year follow-up, 87.5% of the patients maintained normoglycaemia. None of the patients developed T2DM after surgery. 26.9% of patients achieved absolute weight loss at one year after bariatric surgery and maintained this at two and three years post surgery (p < 0.001 vs. baseline). The homeostatic model assessment-insulin resistance index in patients also decreased from 5.50 at baseline to 1.20, 1.14 and 1.44 at one, two and three years, respectively (p < 0.001). CONCLUSION: Bariatric surgery produces significant weight loss, and leads to reversion from the pre-diabetic state to normal glycaemic status and reduction of the incident DM rate in those with pre-DM and morbid obesity.

Platelet membrane CD154 and sCD154 in progressive peripheral arterial disease: a pilot study.

OBJECTIVE: The expression and potential role of platelet membrane CD154 and sCD154 in atherosclerosis was investigated in patients with peripheral arterial disease. METHODS: This prospective observational study measured the expression of platelet-bound CD154 and soluble CD154 (sCD154) in 39 patients with critical limb ischaemia (CLI, n=15), stable intermittent claudication (SIC, n=12) and age-matched controls (AMC, n=12). Basal and agonist-stimulated CD154, P-selectin expression and fibrinogen binding was measured by whole blood flow cytometry, while sCD154 was measured in paired plasma samples by ELISA. RESULTS: Basal expression of CD154 on the platelet surface was enhanced in both groups of patients with peripheral arterial disease. However, the critical limb ischaemics showed the highest level of basal expression 0.7+/-0.3 [median+/-IQR] and was significantly increased compared to both stable intermittent claudicants and age-matched controls (P<0.001). On agonist stimulation with either ADP or thrombin critical limb ischaemics demonstrated greater platelet reactivity and propensity to express CD154 compared to age-matched controls (P<0.05). Confirmation of the cellular expression of CD154 results was obtained by measuring sCD154 concentrations in autologous plasma samples. Here plasma levels of sCD154 in critical limb ischaemics were significantly greater than both stable intermittent claudicants and age-matched controls (P<0.005). CONCLUSIONS: Enhanced basal platelet expression and increased propensity to express CD154 and sCD154 in critical limb ischaemics compared to both controls and patients with stable intermittent claudication support evidence for the role of CD154 in atherogenesis and suggest a novel function in progressive and acute peripheral arterial disease.

The Effects of Sleeve Gastrectomy and Gastric Bypass on Branched-Chain Amino Acid Metabolism 1 Year After Bariatric Surgery.

BACKGROUND: Weight loss, early after Roux-en-Y gastric bypass (GB) surgery, is associated with reduced concentrations of plasma branched-chain amino acids (BCAAs) and improved insulin sensitivity. Herein, we evaluated whether changes in BCAAs and insulin sensitivity persist with weight stabilization (1 year) after GB or sleeve gastrectomy (SG). METHODS: We prospectively examined 22 severely obese patients (mean age 40.6 ± 2.1 years, BMI 38.8 ± 1.3 kg/m(2), and 59.1 % female) who underwent SG (n = 12) or GB (n = 10) for morbid obesity. Body fat composition was measured with dual X-Ray absorptiometry and abdominal fat volume with computed tomography. BCAAs and acylcarnitines were profiled using liquid chromatography with tandem mass spectrometry. Insulin resistance was calculated using the homeostasis model assessment for insulin resistance (HOMA-IR) formula. RESULTS: At 1-year follow-up, the decrease in BMI, body weight, total fat mass (TFM), fat free mass, and visceral adipose tissue (VAT) was similar between SG and GB. HOMA-IR was associated with BCAA concentrations, and both were decreased equally in both surgical groups. In multivariate analysis with BCAAs, TFM, and VAT as independent factors, only VAT remained significantly associated with insulin resistance. CONCLUSIONS: The metabolic benefits from bariatric surgery, including the changes in BCAA profile, are comparable between SG and GB. The reduction in BCAAs and improvement in the AC profiles after bariatric surgery persists up to 12 months after surgery and may not be surgical related but is influenced primarily by the amount of weight loss, in particular the reduction in visceral adiposity.

Health Promotion Board-Ministry of Health Clinical Practice Guidelines: Obesity.

The Health Promotion Board (HPB) has developed the Clinical Practice Guidelines (CPG) on Obesity to provide health professionals in Singapore with recommendations for evidence-based interventions for obesity. This article summarises the introduction, epidemiology and executive summary of the key recommendations from the HPB-MOH CPG on Obesity for the information of SMJ readers. The chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Health Promotion Board website: http://www.hpb.gov.sg/cpg-obesity. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Surgical implications of ischemic preconditioning.

BACKGROUND: Ischemic preconditioning (IP) has emerged as a powerful experimental method of ameliorating ischemic injury in a variety of organs. This systematic review examines the surgical implications of this phenomenon. Data Source A MEDLINE search was conducted to identify laboratory and clinical studies investigating IP-induced protection in a variety of organ systems. Particular emphasis was placed on uncovering evidence for the use of IP in the surgical setting. DATA SYNTHESIS: Human clinical trials using IP have been successfully carried out in the fields of cardiac, hepatic, and pulmonary surgery. Epidemiologic data exist to support the existence of IP-induced neuroprotection in humans. Human skeletal muscle has been preconditioned experimentally, as have human proximal tubule (renal) cells. At present, there is no evidence for IP occurring in the human intestine, although animal studies attest to the possibility. Ischemic preconditioning appears to be effective even when applied to a site remote to the organ exposed to ischemia. However, these favorable effects are less evident in diabetic and elderly patients. CONCLUSION: Ischemic preconditioning is safe for use in elective cardiac, hepatic, and pulmonary surgery. More studies with greater patient numbers need to be carried out in these areas to demonstrate the efficacy of IP in providing clinical benefit in terms of reducing morbidity and mortality. Although laboratory and experimental evidence is favorable, clinical studies using IP in orthopedic, vascular, reconstructive, transplantation, and gastrointestinal surgery are lacking.

Necrotizing fasciitis: clinical presentation, microbiology, and determinants of mortality.

BACKGROUND: Necrotizing fasciitis is a life-threatening soft-tissue infection primarily involving the superficial fascia. The present report describes the clinical presentation and microbiological characteristics of this condition as well as the determinants of mortality associated with this uncommon surgical emergency. METHODS: The medical records of eighty-nine consecutive patients who had been admitted to our institution for necrotizing fasciitis from January 1997 to August 2002 were reviewed retrospectively. RESULTS: The paucity of cutaneous findings early in the course of the disease makes the diagnosis difficult, and only thirteen of the eighty-nine patients had a diagnosis of necrotizing fasciitis at the time of admission. Preadmission treatment with antibiotics modified the initial clinical picture and often masked the severity of the underlying infection. Polymicrobial synergistic infection was the most common cause (forty-eight patients; 53.9%), with streptococci and enterobacteriaceae being the most common isolates. Group-A streptococcus was the most common cause of monomicrobial necrotizing fasciitis. The most common associated comorbidity was diabetes mellitus (sixty-three patients; 70.8%). Advanced age, two or more associated comorbidities, and a delay in surgery of more than twenty-four hours adversely affected the outcome. Multivariate analysis showed that only a delay in surgery of more than twenty-four hours was correlated with increased mortality (p < 0.05; relative risk = 9.4). CONCLUSIONS: Early operative débridement was demonstrated to reduce mortality among patients with this condition. A high index of suspicion is important in view of the paucity of specific cutaneous findings early in the course of the disease.

Can bariatric surgery be performed safely in patients with severe treatment-resistant asthma?

Obesity-associated severe asthma is a distinct phenotype characterised by resistance to standard asthma therapies. Bariatric surgery appears to be a viable alternative for those who have failed trials of traditional weight loss methods. However, anaesthetic and surgical risks are potential barriers. We describe three patients with treatment-resistant obesity-associated severe asthma who underwent bariatric surgery without complications due to the multidisciplinary perioperative planning and care involved in these complex cases. All three patients showed improvements in asthma control and reduction in maintenance medication use post-surgery.

Impact of bariatric surgery on the management of type 2 diabetes mellitus in Singapore.

INTRODUCTION: Obesity is a risk factor for type 2 diabetes mellitus (T2DM). Metabolic-bariatric surgery (MBS) results in significant weight loss with dramatic improvement in T2DM. This study analysed the effects of MBS on patients with T2DM in a tertiary centre in Singapore. METHODS: Individuals with T2DM who underwent MBS in a single centre from September 2008 to May 2012, with at least 12 months of regular follow-up, were included in our study. The primary outcome measure was good glycaemic control (glycated haemoglobin [HbA1c] < 6.5%, with or without medications) 12 months after surgery. Secondary outcome measures were partial DM remission (fasting blood glucose [FBG] < 7.0 mmol/L and HbA1c < 6.5% without DM medications), complete DM remission (FBG < 5.6 mmol/L and HbA1c < 6.0% without DM medications), weight, body mass index, blood pressure, and fasting serum lipid, serum glucose and serum insulin levels. RESULTS: Of the 19 patients who met the inclusion criteria, 14 underwent gastric bypass and 5 underwent sleeve gastrectomy. At 12 months postoperatively, 17 (89.5%) patients achieved good glycaemic control. DM remission was achieved in 14 (73.7%) patients, with 10 (52.6%) attaining complete remission. CONCLUSION: In Singapore, MBS is an effective treatment modality for obese patients with T2DM. Despite the small sample size and lack of matched controls, the present study suggests that MBS is effective in achieving significant weight loss and eliciting a significant and sustainable improvement in the glycaemic control of patients with T2DM, for up to 12 months.

Bariatric surgery in Singapore from 2005 to 2009.

INTRODUCTION: Obesity is a major public health concern worldwide, including Singapore. Bariatric surgery has grown in popularity to combat this situation, and innovations in this field have led to the emergence of new bariatric procedures. For the healthy growth of this specialized field of surgery, it is mandatory to audit the progress and state of bariatric surgery at regular intervals. METHODS: An e-mail questionnaire survey was conducted in all the leading hospitals of Singapore practicing bariatric surgery between 2005 and 2009. All four hospitals to which the questionnaire survey was mailed responded. The responses from these hospitals were tabulated and analyzed. RESULTS: Between 2005 and 2009, a total of 278 bariatric procedures were performed on 151 men and 127 women with a mean age of 40.34 years (range: 18-64 years) by 12 practicing surgeons. The mean body mass index was 42.25 kg/m(2) (range: 31.4-73 kg/m(2)). All the operations were performed laparoscopically. The most commonly performed procedure was adjustable gastric banding (81.65%), followed by sleeve gastrectomy (13.66%) and Roux en Y gastric bypass (3.95%). CONCLUSION: There is a flux of newer procedures in Singapore. Adjustable gastric banding, which was the only available procedure being performed in 2004, was gradually being replaced by other procedures such as sleeve gastrectomy and Roux-en-Y gastric bypass in 2009.

Bariatric surgery in Asia in the last 5 years (2005-2009).

Obesity is a major public health concern around the world, including Asia. Bariatric surgery has grown in popularity to combat this rising trend. An e-mail questionnaire survey was sent to all the representative Asia-Pacific Metabolic and Bariatric Surgery Society (APMBSS) members of 12 leading Asian countries to provide bariatric surgery data for the last 5 years (2005-2009). The data provided by representative members were discussed at the 6th International APMBSS Congress held at Singapore between 21st and 23rd October 2010. Eleven nations except China responded. Between 2005 and 2009, a total of 6,598 bariatric procedures were performed on 2,445 men and 4,153 women with a mean age of 35.5 years (range, 18-69years) and mean BMI of 44.27 kg/m(2) (range, 31.4-73 kg/m(2)) by 155 practicing surgeons. Almost all of the operations were performed laparoscopically (99.8%). For combined years 2005-2009, the four most commonly performed procedures were laparoscopic adjustable gastric banding (LAGB, 35.9%), laparoscopic standard Roux-en-Y gastric bypass (LRYGB, 24.3%), laparoscopic sleeve gastrectomy (LSG, 19.5%), and laparoscopic mini gastric bypass (15.4%). Comparing the 5-year trend from 2004 to 2009, the absolute numbers of bariatric surgery procedures in Asia increased from 381 to 2,091, an increase of 5.5 times. LSG increased from 1% to 24.8% and LRYGB from 12% to 27.7%, a relative increase of 24.8 and 2.3 times, whereas LAGB and mini gastric bypass decreased from 44.6% to 35.6% and 41.7% to 6.7%, respectively. The absolute growth rate of bariatric surgery in Asia over the last 5 years was 449%.

Bare nitinol stent enabled recanalization of long-segment, chronic total occlusion of superficial femoral and adjacent proximal popliteal artery in diabetic patients presenting with critical limb ischemia.

PURPOSE: To evaluate our experience of limb salvage with bare nitinol stent enabled recanalization of long length occlusions of superficial femoral artery (SFA) and adjacent proximal popliteal artery (PPA) in diabetic patients. METHODS: A total of 573 patients underwent 842 lower limb interventions from August 2006 to September 2008 at our institute. A retrospective review was done of diabetic patients undergoing recanalization of long length SFA/adjacent PPA (>10 cm) occlusions with self expanding bare nitinol stents evaluating their impact on limb salvage. RESULTS: Forty-four patients (mean age 65.2 years, M:F 25:19) underwent 49 long-length (>10 cm) SFA/PPA stenting procedures over a period of 26 months. Diabetics comprised 66% of patients (n=29, mean age: 63.7 years, M: F 19:10). The infrapopliteal distal run-off in this diabetic subgroup comprised one vessel (n=14/29, 48%), two vessels (n=12/29, 41%), and three vessels (n=3/29, 10%). The spectrum of critical limb ischemia included rest pain (n=8), ulcer (n=7) and gangrene (n=14). The lengths of occlusions recanalized were 10-39 cm. A total of 58 stents (individual length 10-17 cm, average diameter 6 mm, mean 2 stents per patient) were placed with average length of stented segment being 23.8 cm. Four patients had stents placed through ipsilateral popliteal artery approach with rest placed through femoral artery approach. Significant complications of the procedure included distal embolization (n=3) successfully managed with thrombolysis and popliteal arteriovenous fistula in one patient undergoing recanalization through popliteal approach, managed with covered stent placement. No procedure related mortality occurred during thirty-day follow-up period. All were followed up over an average duration of twelve months post-procedure. Three patients died due to associated medical conditions during this period. The following amputations were done on follow-up (three toe amputations, five forefoot amputations, three below-knee amputations, two above-knee amputations). The overall limb salvage rate was 80%. CONCLUSION: Our study shows beneficial result of SFA/PPA stent placement in diabetic occlusions with significant concomitant infrapopliteal disease.

Peroral dual scope for natural orifice transluminal endoscopic surgery (NOTES) gastrotomy closure.

BACKGROUND: Although transgastric intraperitoneal surgery is feasible both in experimental models and humans, secure gastrotomy closure remains challenging. As there is still no method that is simple, reliable, inexpensive, and effective, we aimed to evaluate the feasibility, efficacy, and safety of a novel endoscopic approach to this issue that intends to ensure secure healing by obtaining full thickness gastric wall apposition without requiring specialized instrumentation. METHODS: Six pigs underwent general anesthesia followed by peritoneoscopy through a 12-mm gastrotomy by a double-channel endoscope. Gastrotomy closure was performed by our innovative technique. In short, this involves the insertion of a second single-channel gastroscope alongside the NOTES gastroscope. Both scopes are then worked in tandem within the stomach by separate operators using conventional endoscopic graspers and an endoclip device. The first animal was used to ascertain feasibility and standardize the technical steps, whereas the other five were survived. Postoperative follow-up then included endoscopy 1 week later and repeat endoscopy, laparoscopy, and necropsy on day 14. RESULTS: All closures were immediately successful. Postoperatively, each animal demonstrated appropriate weight gain and behavioral pattern without overt postoperative complication. Necropsy showed normal healing at the gastrotomy site although there were signs of minor peritoneal irritation and infection in 2 pigs. CONCLUSIONS: This transoral dual-scope clipping method of gastrotomy closure after NOTES, as well as the general concept of employing 2 separate instruments at the same time perorally, is proven technically feasible, safe, and effective in this model.