Efficient passivation of n-type and p-type silicon surface defects by hydrogen sulfide gas reaction.

An efficient surface defect passivation is observed by reacting clean Si in a dilute hydrogen sulfide-argon gas mixture (<5% H2S in Ar) for both n-type and p-type Si wafers with planar and textured surfaces. Surface recombination velocities of 1.5 and 8 cm s-1are achieved on n-type and p-type Si wafers, respectively, at an optimum reaction temperature of 550 °C that are comparable to the best surface passivation quality used in high efficiency Si solar cells. Surface chemical analysis using x-ray photoelectron spectroscopy shows that sulfur is primarily bonded in a sulfide environment, and synchrotron-based soft x-ray emission spectroscopy of the adsorbed sulfur atoms suggests the formation of S-Si bonds. The sulfur surface passivation layer is unstable in air, attributed to surface oxide formation and a simultaneous decrease of sulfide bonds. However, the passivation can be stabilized by a low-temperature (300 °C) deposited amorphous silicon nitride (a-Si:NX:H) capping layer.

Refractory hypercalcaemia secondary to localised gastrointestinal stromal tumour.

Gastrointestinal stromal tumours are a rare form of intra-abdominal neoplasm derived from mesenchymal tissue, typically presenting with abdominal pain, anaemia or bleeding into the bowel or abdominal cavity. Hypercalcaemia is an unusual complication, having been documented in only seven previous patients, all of whom had advanced metastatic disease. We present a case of treatment-resistant hypercalcaemia in a patient with non-metastatic gastrointestinal stromal tumour, which resolved following excision of the tumour.

Acute superior vena cava obstruction following Ivor-Lewis oesophagectomy.

A 53 year old man developed upper body swelling, hypotension, anuria and a metabolic acidosis within 24 h following an Ivor-Lewis oesophagectomy. His co-morbidities included hypertension, hypercholesterolaemia, ischaemic heart disease and he was a smoker. He did not have radiotherapy but had received neo-adjuvant chemotherapy through an in-dwelling right subclavian central venous catheter. Azygous vein ligation during oesophagectomy resulted in acute upper body venous hypertension and signs of hypovolaemic shock which were attributed to undiagnosed thrombotic occlusion of the superior vena cava. The patient was anticoagulated and made a full recovery after a period of stay in intensive care.

Presentation and survival of operable esophageal cancer in patients 55 years of age and below.

BACKGROUND: The increased incidence of esophageal cancer, especially in the younger age group, should encourage early diagnosis. The perceived rarity and poor prognostic outcome of esophageal cancer in this group is based on retrospective studies. The goal of this study was to review the presentation and survival of young patients with esophageal cancer. METHODS: This study was conducted from 2000 to 2007 in a specialized esophagogastric center. All patients who had esophageal cancer operations were included. Variables collected included ages, duration of symptoms, presenting symptoms, tumor characteristics, and follow-up data. RESULTS: In total, 365 esophagectomies were performed for cancer, of which 76 patients were younger than aged 55 years (20.8%) and 289 were older than aged 55 years. In patients younger than aged 55 years, 15 patients had symptoms for 6 months or more, 54 had dysphagia, 35 had weight loss compared with 220 and 175 respectively of patients older than aged 55 years. On histopathology, 48 had T3 tumors (63.2%), 17 had T2 (22.4%), and 10 had T1 (13.2%) for patients younger than aged 55 years compared with 141 had T3 (48.7%), 85 had T2 (29.4%), and 55 had T1 (19%) for patients older than aged 55 years. These differences in tumor stage at presentation between groups were significant (p < 0.05 with 3DF). In-hospital mortality was 0 for the group younger than aged 55 years and 5 for those older than aged 55 years. Average follow-up was 35 (minimum, 15) months. Thirty patients had locoregional recurrence in the first group and 110 in the latter group. Survival at 1 year after surgery was 79.6%, at 2 years 65.1%, and at 5 years 42.3% compared with 78.4, 60.6, and 45.9%, respectively, for the group older than aged 55 years, but this was not significant using log-rank (p = 0.99). CONCLUSIONS: A significant proportion (20.8%) of patients presenting with operable esophageal cancer was younger than aged 55 years. Almost two-thirds of those presenting younger than aged 55 years had T3 stage tumors, which was significantly different than those older than aged 55 years. Despite more advanced tumor stage at presentation, the prognosis of esophageal cancer for patients younger than aged 55 years is similar to those older than aged 55 years (log-rank = 0.99).

Spontaneous perforation of cervical oesophagus: a rare variant of Boerhaave's syndrome.

BACKGROUND: A 29-year-old man presented with sudden onset of severe pain in his throat, difficulty breathing and a hoarse voice, following an episode of vomiting. INVESTIGATIONS: Initial laboratory tests were normal. The patient underwent fibre-optic nasendoscopy, which demonstrated a haematoma in the piriform fossa. Lateral neck radiography and subsequent computed tomography scanning confirmed a 2 cm, loculated, gas-containing collection at the level of the vallecula in the right posterolateral wall, extending to the false vocal folds and communicating between the right parapharyngeal space and the right carotid sheath. Water-soluble contrast swallow confirmed the diagnosis. DIAGNOSIS: Contained oesophageal perforation. MANAGEMENT: Conservative treatment was adopted involving nil orally, intravenous antibiotics and nasogastric feeding. The patient made an uneventful recovery.

Transhiatal oesophagectomy: techniques, tips and outcomes.

AIM: To demonstrate our technique and valuable tips for transhiatal oesophagectomies. METHOD: 215 patients underwent transhiatal oesophagectomies in our unit between 2000 and 2006. RESULTS: In-hospital mortality was 0.9%. Anastomotic leak in 12 patients (5.6%). Chyle leak was seen in five patients and recurrent nerve neuropraxia in six patients. Iatrogenic splenectomy rate was 6%. The median operative time was 151 minutes (range 93-276 minutes). Overall median length of hospital stay was 15 days (range 8-95 days). The median survival for all patients undergoing transhiatal oesophagectomy for invasive malignancy was 42.9 months and the one-year and five-year survival were 81% and 48% respectively. CONCLUSION: This is a safe and oncologically sound procedure. We feel that the tips can be helpful for anyone performing this procedure.

Anastomotic strictures and delayed gastric emptying after esophagectomy: incidence, risk factors and management.

The aim of this study was to report the incidence, risk factors, and management of gastric conduit dysfunction after esophagectomy in 177 patients over a 3-year period in a single center. Patients with anastomotic strictures or delayed gastric emptying (DGE) were identified from a prospective database. Anastomotic strictures occurred in 48 patients (27%). Eighty-three percent of early anastomotic strictures (<1 year) were benign, and all late strictures (>1 year) were malignant. Dilatation was effective in 98% of benign and 64% of malignant strictures. DGE occurred in 21 patients (12%), and was associated with both anastomotic leak (P = 0.001) and anastomotic stricture (P = 0.001). 4/8 patients with late DGE (>3 months postesophagectomy) were tumor-related. Pyloric dilatation was effective in 92% of early and 63% of late DGE. Pyloric stents were inserted in 3 patients with tumor-related DGE. After esophagectomy, early anastomotic strictures (within 1 year) and early delayed gastric emptying (within 3 months) are usually benign and respond to dilatation. However, patients presenting later with tumor-related obstruction are unlikely to respond to anastomotic or pyloric dilatation and should be stented.

Training in oesophageal surgery--the gold standard: a prospective study.

INTRODUCTION: Competency in complex oesophagogastric surgery, within the current climate of changes to medical training and reduced hours, requires repeated, focused, hands-on training. We describe the training methods for oesophagectomy in our institution. METHODS: All oesophageal resections under the care of one consultant surgeon are regarded as training cases. When trainees start they are shown the first resection; subsequently, the trainees then perform every case with the consultant scrubbed. Consultant input consists of retraction and tips in difficult situations. All data were collected on a prospective database. RESULTS: Two hundred and seventy patients (215 males, median age=64 years) underwent primary oesophagectomy under the consultant, between January 2000 and May 2007. Fifteen resections (6%) were performed solely by the consultant. ASA grading was: I=15, II=154, III=95, IV=5, and unrecorded=1. In-hospital mortality and clinically apparent leak rate was 1.9% (5 deaths) and 6.2% (n=17), respectively. Reoperation was required in 15 patients (5.5%). The median length of hospital stay was 14 days (range=8-95 days). Median lymph node yield was 13 (range=0-64). CONCLUSIONS: Trainees under supervision can competently perform an oesophagectomy without compromising patient care. An early hands-on approach leads to a rapid ascent of the learning curve and is essential in today's climate of limited training opportunity.

Laparoscopic gastrectomy for gastric cancer: early experience among the elderly.

BACKGROUND: The data are scarce on the outcome for elderly patients presenting with resectable gastric cancer in the West who have been treated with minimally invasive surgery. This report presents the authors' early experience with totally laparoscopic gastric resections for cancer in elderly patients. METHODS: A total of 20 patients underwent laparoscopic gastrectomy procedures: 14 distal, 5 subtotal, and 1 total gastrectomy. The male-to-female ratio was 15 to 5. The ages ranged from 75 to 88 years (mean, 80 years). RESULTS: All cases were managed laparoscopically with R0 resection. Four patients needed high-dependency unit care postoperatively. There were no perioperative deaths. The median time required for the procedure was 212 min, and time to diet was 4 days. The hospital stay was 8 days. Four patients experienced significant complications, with two patients requiring reoperation. The pathology was adenocarcinoma for 17 patients and high-grade dysplasia for 3 patients. CONCLUSION: Among elderly patients for whom conventional gastric surgery carries a high morbidity and mortality risk, minimal access surgery may offer equivalent oncologic integrity but with superior safety and economy. The primary aim is to remove the tumor with at least a D1 lymphadenectomy.

Use of porcine dermal collagen graft and topical negative pressure on infected open abdominal wounds.

This article reports on two cases in which porcine dermal collagen grafts were used successfully alongside topical negative pressure therapy in order to close open abdominal wounds in which severe infection was present.

Does rectus sheath infusion of bupivacaine reduce postoperative opioid requirement?

INTRODUCTION: The aim of this work was to assess the effect of intermittent bupivacaine infusion into rectus sheath space on postoperative opioid requirement, postoperative pain score and peak expiratory flow rate. PATIENTS AND METHODS: A prospective, randomised study involving patients undergoing midline laparotomy. Patients were randomised to receive either intermittent infusion of bupivacaine 0.25% or normal saline via catheters placed in the rectus sheath for 48 h after operation. All patients received intravenous morphine infusion on demand with a patient-controlled analgesic device (PCAD). RESULTS: Forty ASA I-III patients were studied. Nineteen were randomised to receive bupivacaine and 21 patients received normal saline. Patient characteristics and surgical variables were comparable in the two groups. The mean wound lengths were similar. There was no statistically significant difference in postoperative opioid requirement, postoperative pain score and peak expiratory flow rate between the two groups. CONCLUSIONS: Intermittent bupivacaine infusion into the rectus sheath space after midline laparotomy does not reduce postoperative opioid requirement nor does it affect postoperative pain score or peak expiratory flow rate.

Laparoscopic management of a torted appendix.

Torted appendices are a rare occurrence but should be considered when encountering a haemorrhagic congested appendix on laparoscopy. As adhesions are rarely present, laparoscopic excision is usually a feasible option.

Mirizzi syndrome: laparoscopic management by subtotal cholecystectomy.

BACKGROUND: The authors present their experience with laparoscopic subtotal cholecystectomy for the management of Mirizzi's syndrome and their review of the literature. METHODS: Over a period of 24 months, five cases of Mirizzi's syndrome were encountered, representing 1.5% of all the laparoscopic cholecystectomies performed in the authors' unit. The sex ratio was 4 females to 1 male, and the mean age of the patients was 66 years. All underwent a subtotal cholecystectomy. RESULTS: All procedures were completed laparoscopically. Morbidities involved one case of biliary peritonitis and a one case of biliary leak requiring endoscopic stenting. CONCLUSION: Mirizzi's syndrome cannot always be anticipated on the basis of preoperative staging, and often is encountered during the procedure. The "anatomic scenario" of this condition should be suspected for patients presenting with conditions such as empyema or mucocoele when there is a likelihood of stone impaction in the infundibulum of the gallbladder. Subtotal cholecystectomy with secure intraperitoneal biliary drainage appears to be a safe option for these patients.

An audit of cystic duct closure in laparoscopic cholecystectomies.

BACKGROUND: Cystic duct leak is an infrequent but potentially serious complication of laparoscopic cholecystectomy. The aims of this audit were to assess the efficacy of locking absorbable clips for closing the cystic duct and to compare the results with those for simple clips used previously. METHODS: The records for all laparoscopic cholecystectomies performed in one hospital over a 5-year period were reviewed. The results were compared using Fisher's exact test. RESULTS: Of 518 laparoscopic cholecystectomies attempted, 24 were excluded. There was no difference in age or sex ratio between the two groups. Cystic duct leaks were identified either on endoscopic retrograde choloangio pancreatography or at laparotomy. No cystic duct leak occurred in any of the 344 locking clip cases, as compared with 3 leaks in the 146 (2%) simple clip cases (p < 0.03). CONCLUSION: Locking clips are a safe and effective method for cystic duct closure. They are associated with a reduced cystic duct leak rate, as compared with that for simple clips.

Left subcostal closed (Veress needle) approach is a safe method for creating a pneumoperitoneum.

BACKGROUND: The left subcostal closed approach utilizing the Veress needle has been the preferred method at one surgical practice for the past 5 years. The aims of this study were to determine whether this was a safe method for creating a pneumoperitoneum and its success rate. METHODS: The medical records for all laparoscopic procedures performed at one practice from 1996 through 2001 were reviewed. RESULTS: A total of 352 laparoscopic cases were reviewed. The median age of the patients was 55 years (range, 14-72), with a sex ratio of 1 male to 3.5 females. The left subcostal closed approach was not attempted in 8 patients (2%) due to left subcostal surgical scars. The left subcostal approach was successful in 342 of 344 attempts (99%). In 2 patients the method failed because the Veress needle hole could not be placed in the peritoneal cavity. An omental hematoma in one patient was the only complication. CONCLUSION: The left subcostal closed approach is a safe and effective method for creating a pneumoperitoneum.