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Biomedical subjects

R A Malthaner

Publications and source records attributed to R A Malthaner.

At least 19 recordsLinked to original sources

3D thoracoscopic ultrasound volume measurement validation in an ex vivo and in vivo porcine model of lung tumours.

The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial "tumours" were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the "tumours" were implanted into the lung tissue in both a porcine lung sample ex vivo and a surgical porcine model in vivo. 3D US images were created by mechanically rotating the thoracoscopic ultrasound probe about its long axis while the transducer was maintained in close contact with the tissue. Volume measurements were made by one observer using the ultrasound images and a manual-radial segmentation technique and these were compared with the known volumes of the agar. In vitro measurements had average accuracy and precision of 4.76% and 1.77%, respectively; in vivo measurements had average accuracy and precision of 8.18% and 1.75%, respectively. The 3D thoracoscopic ultrasound can be used to accurately and reproducibly measure "tumour" volumes both in vivo and ex vivo.

Agar↗

Stapled versus conventional surgery for hemorrhoids.

BACKGROUND: Hemorrhoids are one of the most common anorectal disorders. The Milligan‐Morgan open hemorrhoidectomy is the most widely practiced surgical technique used for the management of hemorrhoids and is considered the current "gold standard". Circular stapled hemorrhoidopexy was first described by Longo in 1998 as alternative to conventional excisional hemorrhoidectomy. Early, small randomized‐controlled trials comparing stapled hemorrhoidopexy with traditional excisional surgery have shown it to be less painful and that it is associated with quicker recovery. The reports also suggest a better patient acceptance and a higher compliance with day‐case procedures potentially making it more economical. A previous Cochrane Review of stapled hemorrhoidopexy and conventional excisional surgery has shown that the stapled technique is associated with a higher risk of recurrent hemorrhoids and some symptoms in long term follow‐up. Since this initial review, several more randomized controlled trials have been published that may shed more light on the differences between the novel stapled approach and conventional excisional techniques. OBJECTIVES: This review compares the use of circular stapling devices and conventional excisional techniques in the surgical treatment of hemorrhoids. Its goal is to ascertain whether there is any difference in the outcomes of the two techniques in patients with symptomatic hemorrhoids. SEARCH STRATEGY: We searched all the major electronic databases (MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from 1998 to December 2009. SELECTION CRITERIA: All randomized controlled trials comparing stapled hemorrhoidopexy to conventional excisional hemorrhoidal surgeries with a minimum follow‐up period of 6 months were included. DATA COLLECTION AND ANALYSIS: Data were collected on a data sheet. When appropriate, an Odds Ratio was generated using a random effects model. MAIN RESULTS: Patients with SH were significantly more likely to have recurrent hemorrhoids in long term follow up at all time points than those with CH (12 trials, 955 patients, OR 3.22, CI 1.59‐6.51, p=0.001). There were 37 recurrences out of 479 patients in the stapled group versus only 9 out of 476 patients in the conventional group. Similarly, in trials where there was follow up of one year or more, SH was associated with a greater proportion of patients with hemorrhoid recurrence (5 trials, 417 patients, OR 3.60, CI 1.24‐10.49, p=0.02). Furthermore, a significantly higher proportion of patients with SH complained of the symptom of prolapse at all time points (13 studies, 1191 patients, OR 2.65, CI 1.45‐4.85, p=0.002). In studies with follow up of greater than one year, the same significant outcome was found (7 studies, 668 patients, OR 3.14, CI 1.20‐8.22, p=0.02). Patients undergoing SH were more likely to require an additional operative procedure compared to those who underwent CH (8 papers, 553 patients, OR 2.75, CI 1.31‐5.77, p=0.008). When all symptoms were considered, patients undergoing CH surgery were more likely to be asymptomatic (12 trials, 1097 patients, OR 0.59, CI 0.40‐0.88). Non significant trends in favor of SH were seen in pain, pruritis ani, and fecal urgency. All other clinical parameters showed trends favoring CH.

Hemorrhoids↗

Preoperative chemotherapy for resectable thoracic esophageal cancer.

BACKGROUND: Surgery has been the treatment of choice for localized esophageal cancer. A number of studies have investigated whether preoperative chemotherapy followed by surgery leads to an improvement in cure rates but the individual reports have been conflicting. An explicit systematic update of the role of preoperative chemotherapy in the treatment of resectable thoracic esophageal cancer is, therefore, warranted. OBJECTIVES: The objective of this review is to determine the role of preoperative chemotherapy on patients with resectable thoracic esophageal carcinomas. SEARCH STRATEGY: Trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to 2006), EMBASE (1988 to 2006) and CANCERLIT (1993 to 2002). There were no language restrictions. SELECTION CRITERIA: All trials of patients with potentially resectable carcinomas of the esophagus (of any histologic type) who were randomised to having either chemotherapy or no chemotherapy before surgery. DATA COLLECTION AND ANALYSIS: The primary outcome was survival, which was assessed using hazard ratios. This is an amendment to the original review which used relative risks to assess survival at yearly intervals. Hazard ratios (HR) have now been introduced to summarise the complete survival experience in a single analysis. The risk ratio (relative risk; RR) was used to compare rates of resections, tumour recurrences and treatment morbidity and mortality. MAIN RESULTS: There were eleven randomised trials involving 2019 patients. Eight trials (1729 patients) reported sufficient detail on survival to be included in a meta-analysis for the primary outcome. There was some evidence to suggest that preoperative chemotherapy improves survival, but this was inconclusive (HR 0.88; 95% CI 0.75 to 1.04). There was no evidence to suggest that the overall rate of resections (RR 0.96, 95% CI 0.92 to 1.01) or the rate of complete resections (R0) (RR 1.05; 95% CI 0.97 to 1.15) differ between the preoperative chemotherapy arm and surgery alone. There is no evidence that tumour recurrence (RR 0.81, 95% CI 0.54 to 1.22) or non-fatal complication rates (RR 0.90; 95% CI 0.76 to 1.06) differ for preoperative chemotherapy compared to surgery alone. Trials reported risks of toxicity with chemotherapy that ranged from 11% to 90%. AUTHORS' CONCLUSIONS: In summary, preoperative chemotherapy plus surgery may offer a survival advantage compared to surgery alone for resectable thoracic esophageal cancer, but the evidence is inconclusive. There is some evidence of toxicity and preoperative mortality associated with chemotherapy.

Antineoplastic Agents↗

A case of bronchopulmonary carcinoid tumor: the role of octreotide scanning in localization of an ectopic source of ACTH.

BACKGROUND: Bronchopulmonary carcinoids are neuroendocrine tumors. They can present with Cushing's syndrome secondary to ectopic adrenocorticotropic hormone (ACTH) secretion. Curative resection is possible only after adequate localization of the ectopic source. OBJECTIVE: To describe a case that illustrates the role of octreotide scanning in the management of a bronchopulmonary carcinoid. RESULTS: The use of preoperative and postoperative octreotide scanning aided in performing a limited resection, thereby preserving the lung parenchyma. CONCLUSIONS: We propose that octreotide scanning can be a very important and informative test in the management of carcinoid tumors. In situations when conventional imaging is not conclusive, octreotide scanning may be of help in determining the source of ectopic ACTH syndrome.

ACTH Syndrome, Ectopic↗

Cyclosporin versus tacrolimus as primary immunosuppressant after liver transplantation: a meta-analysis.

A systematic review of randomized clinical trials (RCT) was undertaken to evaluate the beneficial and harmful effects of immunosuppression with cyclosporin versus tacrolimus for liver transplanted patients. MEDLINE, EMBASE, Cochrane Central and Hepato-Biliary Group Controlled Trials Registers were searched. Using fixed and random effects model, relative risk (RR), values <1 favoring tacrolimus, with 95% confidence intervals (CI) were calculated. Of 717 potentially relevant references, 16 RCTs were eligible for inclusion. Mortality and graft loss at 1 year were significantly reduced in tacrolimus-treated recipients (Death: RR 0.85, 95% CI 0.73-0.99; graft loss: RR 0.73, 95% CI 0.61-0.86). Tacrolimus reduced the number of recipients with acute rejection (RR 0.81, 95% CI 0.75-0.88) and steroid-resistant rejection (RR 0.54, 95% CI 0.47-0.74) in the first year. Lymphoproliferative disorder or dialysis rates were not different but more de novo diabetes (RR 1.38, 95% CI 1.01-1.86) occurred with tacrolimus. More patients stopped cyclosporin than tacrolimus (RR 0.57, 95% CI 0.49-0.66). Treating 100 recipients with tacrolimus instead of cyclosporin would avoid rejection and steroid-resistant rejection in nine and seven patients respectively, graft loss and death in five and two patients respectively, but four additional patients would develop diabetes after liver transplantation.

Acute Disease↗

The role of surgery and postoperative chemoradiation therapy in patients with lymph node positive esophageal carcinoma.

BACKGROUND: Patients who have undergone resection for lymph node positive esophageal carcinoma are at high risk of disease recurrence and early death. The role of postoperative adjuvant therapy in this population needs to be determined. METHODS: A retrospective review of all patients with resected esophageal carcinoma between 1991 and 1997 was performed. Lymph node positive (N1) patients who received concurrent or sequential postoperative radiotherapy (50 grays) and chemotherapy (cisplatin, 5-fluorouracil with or without epirubicin) were compared with N1 patients who underwent surgery alone. The disease free and overall survival rates were calculated using the Kaplan-Meier method, and groups were compared with the log-rank test. Prognostic variables were entered into a Cox regression model controlling for age, weight loss, T status, Eastern Cooperative Oncology Group (ECOG) score, and treatment received. RESULTS: A total of 165 patients were reviewed: Twenty-eight N1 patients underwent surgery alone (S group), and 38 N1 patients underwent surgery and received postoperative chemoradiation therapy (CRT group). Preoperative risk factors, tumor characteristics, ECOG scores, and lengths of hospital stay were similar. The disease free survival rates were similar (S group, 10.6 months; CRT group, 10.2 months), although the S group had more local disease recurrences (S group, 35%; CRT group, 13%; P = 0.09). The overall survival rate according to the Kaplan-Meier analysis showed a significant survival advantage with postoperative CRT radiation (log-rank test; P = 0.001). The median overall survival for the CRT group was 47.5 months, which was significantly longer than that of the S group (14.1 months). The ECOG score, T status, and treatment received all were found to influence survival significantly on univariate analysis. In the multivariate model, postoperative CRT was a predictor of survival (P = 0.007; risk ratio for mortality, 0.35; 95% confidence interval, 0.16-0.76) and was correlated with a significantly decreased risk of death in patients with lymph node positive, resected esophageal carcinoma. CONCLUSIONS: Postoperative CRT appears to prolong survival in patients with lymph node positive, resected esophageal carcinoma.

Aged↗

Intraoperative radioguided thoracoscopic removal of ectopic parathyroid adenoma.

Twenty-five percent of primary hyperparathyroidism is caused by ectopic mediastinal parathyroid glands, with 2% of these not accessible to standard cervical surgical approaches. Advancement in video-assisted thoracoscopic surgical techniques has decreased the need for sternotomy to successfully remove these ectopic glands. The thoracoscopic approach, however, is limited by the surgeon's inability to always accurately visualize ectopic glands. Intraoperative radionuclide-guided dissection, using a thoracoscopic approach, provides a novel adjunct to the removal of occult ectopic parathyroid glands. We report a case of an occult ectopic parathyroid adenoma removed thoracoscopically using an intraoperative handheld gamma probe.

Adenoma↗

Current practice of abdominal fascial closure: a survey of Ontario general surgeons.

OBJECTIVES: To determine the current practice of abdominal fascial closure among provincial general surgeons. The primary objective was to determine the proportion of surgeons choosing absorbable versus nonabsorbable sutures. Secondary objectives included determining knowledge and attitudes of surgeons to evidence-based medicine and concordance of current practice with level I evidence. DESIGN: A survey. SETTING: The province of Ontario. PARTICIPANTS: One hundred general surgeons. METHODS: A stratified random sample of community and academic surgeons was assembled and a questionnaire was mailed to them. Common clinical scenarios and questions pertaining to attitudes and knowledge of evidence-based medicine were included. MAIN OUTCOME MEASURES: Use of absorbable versus nonabsorbable suture material. Willingness to change current practice on evidence-based level I reports. RESULTS: Most surgeons (86%) chose an absorbable suture for abdominal fascial closure. Nonabsorbable suture was chosen by 58% of surgeons in the highly contaminated surgical scenario. Eighty-one percent of surgeons indicated they would be willing to change their current practice of fascial closure if there was evidence that the incidence of wound complications was reduced. Polyglactin (Vicryl) was the most commonly chosen suture. CONCLUSIONS: The current practice of abdominal fascial closure among Ontario general surgeons is in disagreement with the findings from a recent meta-analysis, recommending a nonabsorbable suture for a 32% relative risk reduction in the incisional hernia rate. The majority of surgeons employ a continuous absorbable closure in common surgical scenarios. A definitive randomized controlled trial comparing continuous nonabsorbable closure versus continuous absorbable closure is warranted.

Abdomen↗

The search for an ideal method of abdominal fascial closure: a meta-analysis.

BACKGROUND AND OBJECTIVE: The ideal suture for abdominal fascial closure has yet to be determined. Surgical practice continues to rely largely on tradition rather than high-quality level I evidence. The authors conducted a systematic review and meta-analysis of randomized controlled trials to determine which suture material and technique reduces the odds of incisional hernia. METHODS: MEDLINE and Cochrane Library databases were searched for articles in English published from 1966 to 1998 using the keywords "suture", "abdomen/surgery", and "randomized controlled trials". Randomized controlled trials, trials of adult patients, and trials with a Jadad Quality Score of more than 3, comparing suture materials, technique, or both, were included. Two independent reviewers critically appraised study quality and extracted data. The reviewers were masked to the study site, authors, journal, and date to minimize bias. The primary outcome was postoperative incisional hernia. Secondary outcomes included wound dehiscence, infection, wound pain, and suture sinus formation. RESULTS: The occurrence of incisional hernia was significantly lower when nonabsorbable sutures were used. Suture technique favored nonabsorbable continuous closure. Suture sinuses and wound pain were significantly lower when absorbable sutures were used. There were no differences in the incidence of wound dehiscence or wound infection with respect to suture material or method of closure. Subgroup analyses of individual sutures showed no significant difference in incisional hernia rates between polydioxanone and polypropylene. Polyglactin showed an increased wound failure rate. CONCLUSIONS: Abdominal fascial closure with a continuous nonabsorbable suture had a significantly lower rate of incisional hernia. The ideal suture is nonabsorbable, and the ideal technique is continuous.

Abdominal Muscles↗

Lung volume reduction surgery: results of a Canadian pilot study. Canadian Lung Volume Reduction Surgery Study Group.

OBJECTIVE: To present preliminary experience with lung volume reduction surgery (LVRS) before the institution of the Canadian LVRS trial. DESIGN: A prospective case series between December 1995 and January 1997. SETTING: University hospitals in London and Hamilton, Ont. PATIENTS: Forty-nine patients who had disabling dyspnea or emphysema with hyperinflation, able to participate in respiratory rehabilitation. Twenty-three patients were excluded because of comorbid conditions precluding surgery, pulmonary hypertension, excessive steroid dependence, malnutrition, obesity, previous thoracotomy, large solitary bullae, concurrent malignant disease, chronic bronchitis, hypercapnia or psychiatric illness. INTERVENTIONS: Preoperative respiratory rehabilitation followed by LVRS via median sternotomy. MAIN OUTCOME MEASURES: Impairment, disability and handicap were assessed before and 12 months after LVRS. Impairment was assessed by changes in pulmonary function test results and blood gas measurements, disability by the 6-minute walk test and cardiopulmonary exercise test, and handicap by the disease-specific chronic respiratory disease questionnaire (CRQ), the generic medical outcomes survey short form 36 (SF-36) and the generic health utilities index mark III (HUI-III). RESULTS: Two patients died of respiratory failure while in rehabilitation. Twenty-four patients (17 men, 7 women) successfully completed rehabilitation and underwent LVRS. The mean age was 63 years (range from 49 to 78 years) and the median length of hospital stay was 12.5 days (range from 7 to 90 days). Two patients (8%) died in the early postoperative period (within 30 days) of pneumonia. One patient died of respiratory failure 8 months after LVRS after a difficult 90-day postoperative hospital stay. There were 27 major complications. There was a 36% relative increase in the mean forced expiratory volume in the first second (p = 0.01) and a 10% relative increase in the 6-minute walk test (p = 0.06). The mean CRQ dyspnea score increased 2.3 points (p = 0.01), and the SF-36 general health domain increased 20 points (p = 0.01). There was no significant change in the HUI-III (p = 0.73). CONCLUSION: LVRS appears to lessen the respiratory impairment and handicap for at least 1 year in selected patients with advanced emphysema.

Aged↗

Propranolol for the prevention of postoperative arrhythmias in general thoracic surgery.

BACKGROUND: Prevention of postoperative arrhythmias in patients undergoing general thoracic surgery is desirable to prevent morbidity. METHODS: A randomized, double-blind, placebo controlled trial of propranolol (10 mg every 6 hours) for 5 days was undertaken in patients undergoing major thoracic operations to determine whether arrhythmias requiring treatment could be reduced. Secondary outcomes included overall arrhythmia rate, adverse events, and length of stay. Arrhythmias were assessed by 72-hour Holter monitoring. Patients with a history of heart failure, asthma, advanced heart block, preexisting arrhythmias, sensitivity to propranolol, or use of antiarrhythmic drugs were excluded. RESULTS: Using the intention-to-treat principle there was a 70% relative risk reduction from 20% to 6% in the rate of treated arrhythmias with propranolol (p = 0.071, 95% confidence interval 0.6% to 27.2%). Overall arrhythmias were common but usually benign. Adverse effects were common, although generally mild with hypotension and bradycardia being reported more often in the propranolol group. Length of stay was not different. CONCLUSIONS: There was a trend to a reduction in the risk of perioperative arrhythmias with propranolol. Moreover, propranolol was well tolerated showing a slight increase in minor adverse events.

Aged↗

HIV complicates the management of oncological emergencies: a case involving the superior vena cava syndrome.

An association exists between human immunodeficiency virus (HIV) and an increased incidence of lung cancer. Superior vena cava syndrome (SVCS) is an oncological emergency seen in the presence of chest tumours. We report on an otherwise well HIV-positive male who presented with SVCS due to lung cancer. He was commenced on dexamethasone and radiotherapy with curative intent. Treatment was complicated by accelerated steroid- and radiation-induced morbidity. The patient died of disseminated aspergillosis after receiving 27 of 35 planned radiotherapy fractions. The management of SVCS in those with HIV is challenging and requires the judicious use of steroids, antifungal prophylaxis and palliative radiotherapy doses.

Adult↗

Small-bowel necrosis associated with jejunal tube feeding.

OBJECTIVES: To report 3 cases of small-bowel necrosis after jejunal tube feeding and to review the literature concerning this condition. DESIGN: A 5-year retrospective review. SETTING: A 560-bed university-affiliated tertiary-care teaching hospital. PATIENTS: Three patients who had bowel necrosis out of 386 who received jejunal tube feedings. RESULTS: The patients experienced small-bowel necrosis as a consequence of jejunal feeding. The ischemic necrosis was preceded by progressive abdominal pain, distension and high nasogastric output. All 3 patients required extensive small-bowel resection. Although survival was rare in previous reports, our 3 patients survived after prompt surgical intervention and small-bowel resection. CONCLUSIONS: Although the death rate for this condition approaches 70%, timely recognition and surgical intervention can save the patient's life.

Aged↗

Long-term results in surgically managed esophageal achalasia.

The long-term clinical results of surgical treatment for esophageal achalasia were reviewed in 35 patients having a minimum follow-up of 10 years. Group A (n = 22) are those patients whose first procedure (myotomy and Belsey partial fundoplication) was done at our hospital. Group B (n = 13) are those who had undergone one or more previous operations elsewhere. In group A good to excellent results occurred in 21/22 patients (95%) at 1 year, 17/22 (77%) at 5 years, 15/22 (68%) at 10 years, 11/16 (69%) at 15 years, and 6/9 (67%) at 20 or more years. Two patients underwent early reoperation (2 and 5 years) for dysphagia due to incomplete myotomy. Three patients underwent esophagectomy (7, 19, and 23 years) and one patient underwent an antrectomy and Roux-en-Y diversion (23 years) for late-onset complications of reflux. Three of 13 group B patients had had multiple prior operations and had severe reflux damage at presentation and underwent immediate esophagectomy. Ten patients had one or more conservative operations in our hospital, and 4 of these eventually required esophagectomy for disabling reflux. Therefore, there were 10 patients (groups A+B) who underwent esophageal resection, all but 1 of whom had endoscopically documented reflux and 5 of whom had peptic strictures. Six of the 10 esophagectomies were performed more than 10 years (13 to 23 years) after the first operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Advantages of handsewn over stapled bowel anastomosis.

Bowel anastomoses are conventionally performed using a handsewn technique or a stapling device. Each has potential benefits and disadvantages. The most clinically significant complications of the bowel anastomosis are anastomotic leakage and stricture formation. The indices of healing and tissue cohesion were compared dynamically over time in 24 dogs randomized to undergo either a standard two-layer handsewn anastomosis or a stapled anastomosis with the Premium CEEA (United States Surgical Corporation, Norwalk, CT). Animals were sacrificed at 1, 4, 7, and 28 days postoperatively. Each anastomosis was evaluated for anastomotic index, burst pressure, collagen content, and histologic appearance. The anastomotic index was similar on postoperative day (POD) 1, 4, and 7; but on day 28 all handsewn anastomoses had larger diameters than the widest CEEA anastomosis. Burst pressure was higher in handsewn anastomoses at all intervals. Collagen content tended to be higher on POD 7 in the CEEA anastomoses. Histological evaluation showed more complete epithelialization and less inflammation in handsewn anastomoses on POD 28. The higher level of collagen in the CEEA anastomoses on POD 7 may be implicated in the tendency toward stricture formation found with this type of anastomosis. This study demonstrates that the greater speed and ease of the stapled anastomosis is offset by the greater strength, reduced tendency to stricture, and more complete healing of the handsewn anastomosis.

Anastomosis, Surgical↗

Alkaline gastroesophageal reflux in infants and children.

The incidence of alkaline gastroesophageal reflux (GER) was examined in 111 consecutive children referred for evaluation of GER during a 1-year period. The results of 24-hour pH monitoring studies and the medical records were retrospectively evaluated. Acid reflux was defined as occurring whenever the pH was less than 4 and alkaline reflux was defined whenever the pH was greater than 7. The percentage of time that reflux occurred, the number of reflux episodes, the number of episodes greater than 5 minutes, and the longest episode were all recorded. Based on these data, four categories of patients were identified as compared with normal values as determined by Pellegrini et al. When using criteria based on the percentage of time that reflux occurred, the largest group of children with GER was found to reflux acid (50%). However, 27 children (24%) had combined acid and alkaline reflux. Eighteen (16%) had predominantly alkaline reflux. Previously, these 18 children would have been considered as having a low likelihood of reflux by pH criteria. Endoscopic examination showed that pathological evidence of esophagitis occurred in four of the children with pure alkaline reflux. This review shows that symptomatic GER in infants and children may be due to acid or alkaline secretions or a mixture of both. A previously unrecognized cohort exists of children who demonstrate primary alkaline reflux. These patients need to be recognized and may benefit from a therapeutic program specifically designed to control alkaline reflux.

Child↗

Anastomotic compression button: a new mechanical device for sutureless bowel anastomosis.

The anastomotic compression button is a new mechanical device that uses three interlocking polypropylene buttons to produce a sutureless bowel anastomosis. The device is unique in that it allows application of the buttons via a device similar to the popular intraluminal stapler, but it leaves no staples or foreign body of any kind in the bowel wall. The authors compared the 25-mm anastomotic compression button with the 25-mm intraluminal stapler in the colon of dogs. After 28 days, the mucosal blood flow, burst pressure, and anastomotic indices were found to be identical between the anastomotic compression button and the stapler. The anastomotic compression button was easier to use, and microscopic examination showed less ulceration, fibrosis, and inflammation, and better re-epithelialization at the anastomotic compression button site. The anastomotic compression button appears to have the potential to be a superior method compared with stapled anastomoses in the colon.

Anastomosis, Surgical↗