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Biomedical subjects

S Shimi

Publications and source records attributed to S Shimi.

18 recordsLinked to original sources
PubMed1997

Optimal port locations for endoscopic intracorporeal knotting.

Port location is crucial for endoscopic manipulations. The aim of the study was to investigate the influence of manipulation, azimuth, and elevation angles of instruments on endoscopic intracorporeal knotting. The standard task was tying a surgeon's knot. Manipulation angles of 30 degrees , 45 degrees , 60 degrees , 75 degrees , and 90 degrees with equal and unequal azimuth angles and elevation angles of 0 degrees , 30 degrees , and 60 degrees were investigated. The endpoints were the execution time and parameters of knot analysis. The execution time was shorter with 60 degrees than with either 90 degrees or 30 degrees manipulation angles (p < 0.0001 and p < 0. 01). Equal azimuth angles resulted in a shorter execution time than wide unequal angles (p < 0.001). A combination of 60 degrees manipulation angle with 60 degrees elevation angle had the shortest execution time (p < 0.001) and highest performance quality score (p < 0.02). A range of 45 degrees -75 degrees manipulation angles with equal azimuth angles is recommended. As the manipulation angle increases, the elevation angle has to increase accordingly.

Endoscopes↗
PubMed1997

Psychomotor skills for endoscopic manipulations: differing abilities between right and left-handed individuals.

OBJECTIVE: The objective of this study was to compare the psychomotor aptitudes relevant to endoscopic manipulations between right-handed and left-handed subjects. SUMMARY BACKGROUND DATA: There has been little research on the psychomotor performance in relation to minimal access surgery and there are no psychomotor tests to evaluate aspects of psychomotor abilities relevant to endoscopic manipulations. METHODS: A microprocessor-controlled psychomotor tester was developed for objective evaluation of endoscopic performance. The task involved negotiating ten target holes with a probe under videoscopic imaging. Subjects consisted of two groups of 10 medical students: right- and left-handed. After a prestudy familiarization session, each subject performed two test runs with one hand, followed by two runs with the other hand. These test runs were repeated 1 week later. The outcome measures were the total execution time, force on backplate, angular deviations, error rate, and first-time accuracy. RESULTS: A significant difference in the error rate and first time accuracy was observed between subjects (p < 0.001 and p < 0.001, respectively) and between the dominant and nondominant hands (p < 0.001 and p < 0.025, respectively), with no significant change with practice. Right-handed subjects performed better with either hand in terms of error rate (p < 0.001) and first time accuracy (p < 0.001). Practice improved the execution time (p < 0.001) and the degree of angular deviations (p < 0.02). CONCLUSIONS: Right-handed subjects perform less errors and exhibit better first time accuracy. The parameters that improve with practice reflect the positive effect of training, whereas others, such as errors rate and first time accuracy which do not, reflect innate abilities.

Endoscopy↗
PubMed1997

Influence of direction of view, target-to-endoscope distance and manipulation angle on endoscopic knot tying.

INTRODUCTION: The aim of the study was to investigate the influence of (1) the direction of view of the endoscope, (2) the endoscope-to-task distance and (3) the manipulation angle between the instruments on intracorporeal endoscopic knotting. METHODS: Rigid endoscopes (0 degree, 30 degrees and 45 degrees) were introduced with the objective set at distances of 50, 75, 100, 125 and 150 mm from the task. Needle holders were inserted to make 30 degrees, 60 degrees and 90 degrees manipulation angles. The execution time and knot quality parameters of 2700 knots performed by ten surgeons were obtained. RESULTS: There was no significant difference in the execution time or parameters of knot quality with different endoscopes. The longest execution time (median 95 s, P < 0.0001) and the lowest performance quality score (20.61, P < 0.001) were observed at a distance of 50 mm when compared to other distances. A 60 degrees manipulation angle had a shorter execution time (median 71 s, P < 0.0001) and a higher performance quality score (26.84, P < 0.0001) than either 30 degrees or 90 degrees manipulation angles. CONCLUSION: The direction of view of the endoscope had no significant effect on intracorporeal knotting if the optical axis subtended the same angle with the task surface. The optimal ergonomic conditions include an endoscope-to-target distance of 75-150 mm and a manipulation angle of 60 degrees.

Endoscopy↗
PubMed1996

A microprocessor-controlled psychomotor tester for minimal access surgery.

BACKGROUND: There is little reported information on psychomotor performance in relation to minimal access surgery (MAS). METHODS: A microprocessor-controlled endoscopic psychomotor tester (the Dundee Endoscopic Psychomotor Tester-DEPT) has been developed to evaluate psychomotor aspects of MAS. Experiments were conducted on 20 medical undergraduates to evaluate accuracy and reliability of the tester. RESULTS: The study demonstrated a significant difference between subjects (p < 0.01). It also identified three individuals who enacted 16, 22, and 40 errors while the majority (85%) sustained less errors with a median of 4.5. CONCLUSIONS: DEPT provides a standard, reproducible, objective real-time scoring system. It identifies individuals who cannot adjust to endoscopic viewing and therefore manipulate from endoscopic images.

Clinical Competence↗
PubMed1995

Comparison of direct vision and electronic two- and three-dimensional display systems on surgical task efficiency in endoscopic surgery.

Task efficiency and knot strength was evaluated under standardized conditions using direct vision and electronic imaging with two-dimensional (2-D) and three-dimensional (3-D) systems. Three operators with different endoscopic surgical experience tied a surgeon's knot with standard endoscopic instruments using the three different visual systems in random order. Each operator tied 20 knots with each visual system. Median task efficiency (defined as the time to complete the knot) was 35.0 (interquartile range (i.q.r.) 30.3-43.8) s for direct vision and 53.0 (i.q.r. 45.3-62.8) s and 53.5 (i.q.r. 45.0-64.8) s for 2-D and 3-D imaging respectively (P < 0.05). With respect to direct vision, this represented an overall degradation of task efficiency with the use of electronic imaging of 52 per cent, with no detectable difference between 2-D and 3-D imaging. The knot strength, representing the degree of tightening, was weaker with electronic imaging but the difference was not significant due largely to variation between the three operators.

Clinical Competence↗
PubMed1995

Hepatic cryotherapy for liver tumors. Development and clinical evaluation of a high-efficiency insulated multineedle probe system for open and laparoscopic use.

A high-efficiency hepatic cryosurgical unit has been developed and evaluated. It is capable of simultaneously driving three implantable insulated cryoneedle probes. The system has been used to treat 18 patients with secondary and 4 patients with primary liver cancer: open (n = 12), total laparoscopic (n = 6), laparoscopic assisted (n = 4). In three patient laparoscopic cryotherapy was repeated inside 6 months. Intraoperative bleeding was encountered in three patients undergoing high-volume hepatic freezing but the bleeding was easily controlled. A fall in the core body temperature was encountered in 10 out of 22 patients and averaged 0.4 degree C. There was one postoperative death from liver failure in an 80-year-old patient in whom a large hepatoma was frozen. The most consistent postoperative biochemical change was hyperbilirubinaemia (n = 3). A right-sided pleural effusion developed in two patients after freezing of lesions on the superior surface of the right lobe. A survival benefit was encountered in three patients, one with central cholangiocarcinoma and the other two with large solitary secondary deposits (melanoma, colon cancer). Seven patients with multiple metastases and two patients with large hepatomas developed recurrence at the frozen site or elsewhere in the liver inside 12 months of follow-up and no clinical benefit could be demonstrated by cryotherapy in this group. In nine patients, the follow-up has been too short (< 18 months) to permit any conclusion on outcome. The current limitations of hepatic cryotherapy are largely due to incomplete tumor destruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Intraoperative cholangiography during laparoscopic cholecystectomy. Routine vs selective policy.

An audit of routine intraoperative cholangiography in a consecutive series of 496 patients undergoing laparoscopic cholecystectomy has been performed. Cannulation of the cystic duct was possible in 483 patients (97%). The use of portable, digitized C-arm fluorocholangiography was vastly superior to the employment of a mobile x-ray machine and static films in terms of reduced time to carry out the procedure and total abolition of unsatisfactory radiological exposure of the biliary tract. Repeat of the procedure was necessary in 22% of cases when the mobile x-ray equipment was used. Aside from the detection of unsuspected stones in 18 patients (3.9%), routine intraoperative cholangiography identified four patients (0.8%) whose management would undoubtedly have been disadvantaged if intraoperative cholangiography had not been performed.

Bile Ducts↗
PubMed1992

Laparoscopy in the management of pancreatic cancer: endoscopic cholecystojejunostomy for advanced disease.

Following a period of animal experimentation in pigs, a laparoscopic technique for sutured gastrointestinal and bilioenteric anastomoses was developed and its safety and efficacy tested in chronic experiments. The method involves the construction of a preformed external jamming loop knot and continuous suturing using a specially developed Endoski needle. The technique was used to construct a cholecystojejunostomy in five patients with advanced cancer of the pancreas (four hand-sutured and one stapled/sutured). Four of the patients recovered from the procedure with no complications, minimal postoperative discomfort and complete relief of their jaundice. In one patient relief of jaundice was slow due to blockage of the anastomosis by debris and blood clot; this resolved following removal of the inspissated material. This minimally invasive procedure has the potential for complete palliation with short hospital stay and avoids the hazards of endoscopic stenting such as encrustation and cholangitis.

Aged↗
PubMed1992

Laparoscopic reduction, crural repair, and fundoplication of large hiatal hernia.

A technique for laparoscopic reduction, crural repair, and total fundoplication for large symptomatic hiatal hernia is described. The procedure entails the mobilization of the esophagogastric junction with crural repair by a continuous suture technique employing a special pre-formed jamming loop knot, followed by total fundoplication that is fixed proximally to the anterior margin of the diaphragmatic hiatus and distally to the esophagogastric junction. The procedure has been performed in eight elderly patients with a good outcome and accelerated recovery to full activity.

Aged↗
PubMed1992

Sutured laparoscopic cholecystojejunostomy evolved in an animal model.

In a series of acute and chronic experiments conducted in young pigs during a 2-year period, we have evolved a quick knotting technique to start and end a suture line and developed a curved 'Endoski' needle to improve needle passage through the tissues. These have been employed in the construction of cholecystojejunal anastomoses using a semi-closed technique with a single layer (deep seromuscular) of continuous polyglactin sutures. In chronic experiments in pigs, patent well healed bilioenteric anastomoses, which conveyed bile satisfactorily after ligation of the common bile duct, distal to the cystic duct, were achieved. A virtual absence of adhesions in these animals was noted.

Anastomosis, Surgical↗
PubMed1992

Endoscopic oesophagectomy through a right thoracoscopic approach.

A technique of subtotal endoscopic oesophagectomy through the right thoracoscopic approach is described. It has been used in five patients, four with cancer and one with benign motility disorder. The operative blood loss during the endoscopic dissection stage was unmeasurable in four patients and amounted to 300 ml in one. The mean (range) duration of the endoscopic dissection was 3.3 (3.0-4.0) h and of the total procedure was 5.5 (4.5-7.5) h. After the operation, the mean (range) duration of stay in the intensive care unit was 19.5 (16-26) h. From the time of the operation, the mean (range) hospital stay was 11 (8-18) days. One patient developed left vocal cord palsy which prolonged this.

Adult↗
PubMed1991

Laparoscopic cholecystectomy: the Dundee technique.

A total of 61 patients was subjected to laparoscopic cholecystectomy. The procedure was completed in 60 cases and converted to open operation in one (2 per cent). The morbidity rate was low (total 7 per cent, major 2 per cent, blood transfusion rate 5 per cent). The median duration of the laparoscopic cholecystectomy with cholangiography was 135 min (range 65-270 min). The operation took less time to complete in patients with functioning gallbladders than in those with non-functioning fibrotic organs (median 120 versus 175 min). The majority of patients required opiate analgesia despite infiltration of the stab wounds with bupivacaine. The mean (s.d.) hospital stay was 2.9 (1.5) days. The median time to resume work or full activity after discharge was 11 days.

Adult↗
PubMed1991

Laparoscopic ligamentum teres (round ligament) cardiopexy.

A technique of laparoscopic ligamentum teres cardiopexy for reflux oesophagitis unresponsive to medical treatment is described. The procedure has been performed on five patients and on postoperative testing has been shown to achieve competence of the lower oesophageal sphincter by lengthening of the intra-abdominal segment, accentuation of the angle of His and elevation of the pressure in the high pressure zone. All the patients have been relieved of their symptoms by the operation and have not sustained any adverse effects but the follow-up period is short.

Adult↗
PubMed1991

Laparoscopic cardiomyotomy for achalasia.

A technique of laparoscopic cardiomyotomy is described. The procedure has been performed in a patient with manometrically confirmed classical achalasia with complete relief of episodic total dysphagia and no untoward symptoms including reflux. The procedure was followed by minimal postoperative discomfort and the patient was discharged on the third postoperative day. Laparoscopic cardiomyotomy has the advantage of diminished surgical trauma with accelerated recovery, constitutes definitive therapy comparable to standard myotomy, and by being less disruptive of the lower oesophageal fixation it is prone to precipitate gastro-oesophageal reflux.

Adult↗
PubMedDate not supplied

Abdominal wall lift. Low-pressure pneumoperitoneum laparoscopic surgery.

A method of abdominal wall lift has been developed and evaluated clinically in this unit during the past 18 months. It permits the conduct of laparoscopic procedures at an intraabdominal pressure of 6-8 mm Hg. The technique was introduced for laparoscopic surgery in patients with preexisting cardiac disease and chronic bronchitis. The procedure, by lifting both the abdominal wall and the falciform ligament together, also elevates the central portion of the liver (segments 3-5), thereby improving the surgical exposure. For this reason it is now also used in fit patients with ptotic livers or hypertrophied quadrate lobes undergoing laparoscopic cholecystectomy and common bile duct exploration, and to facilitate left subhepatic exposure in patients during laparoscopic antireflux surgery and vagotomy.

Abdominal Muscles↗
PubMedDate not supplied

Endoscopic ultrasonic dissection for thoracoscopic and laparoscopic surgery.

A specifically designed handpiece has been developed for ultrasonic dissection of tissues and organs during minimal-access surgery. The experimental prototype has been evaluated in major endoscopic operations on the esophagus, colon, and rectum (n = 19). The benefits documented by this initial experience include increased dissection efficiency of extensive fibroareolar attachments, safe exposure of major vascular pedicles (especially those located in mesocolic fat), greatly reduced risk of major hemorrhage, and decreased operating time.

Colectomy↗
PubMedDate not supplied

Coaxial curved instrumentation for minimal access surgery.

New coaxial curved and bayonet instruments have been designed which permit controlled dissection and directional change of the functional tip, blunt dissection and lift retraction. The instruments are introduced into the peritoneal and thoracic cavities through flexible re-usable metal cannulae. The excellent ergonomic properties of the new instruments have been confirmed by their use in major laparoscopic and thoracoscopic operations. Coaxial instruments enhance the scope of minimal access surgery and have distinct advantages over the traditional straight instruments.

Biomechanical Phenomena↗