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Biomedical subjects

A Cuschieri

Publications and source records attributed to A Cuschieri.

At least 163 records · Page 9Linked to original sources
PubMed1995

Atraumatic retractor for endoscopic surgery.

A novel retractor has been designed to achieve atraumatic retraction of the liver and displacement of hollow viscera during endoscopic surgery. The functional section of the instrument, when locked, forms a silicon-covered uniplanar hook which can be deployed for horizontal lift of solid organs such as the liver or be used to engage bowel for displacement from the operative field. Following laboratory testing, the instrument has been evaluated clinically and its ease of deployment and atraumatic nature have been confirmed. It has been found to be particularly effective for elevation of the thick fatty left lobe of the liver during antireflux surgery.

Endoscopes↗
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↗
PubMed1995

Comparison of serum CA 72-4 and CA 19-9 levels in gastric cancer patients and correlation with recurrence.

BACKGROUND: This longitudinal prospective study evaluates the serum levels of the tumor markers CA 72-4 and CA 19-9, alone or in combination, in gastric cancer patients. PATIENTS AND METHODS: Serum tumor markers CA 72-4 and CA 19-9 were measured in 52 patients who had gastric adenocarcinomas and 32 with benign gastric disorders. Serial measurements of these markers were carried out in 30 cancer patients at a median follow-up time of 38 months. RESULTS: CA 72-4 and CA 19-9 had sensitivities of 42% and 46% for the preoperative detection of gastric cancer. Sensitivity for the two combined was 63%. CA 72-4 provided 100% specificity, compared to 72% for CA 19-9. Postoperatively, 17 cancer patients remained disease-free. Sixteen of these maintained normal levels of CA 72-4, and 10 of CA 19-9. Thirteen patients developed recurrent disease. In 9, serum CA 72-4 levels rose from near-normal after surgery and reached diagnostic values approximately 6 months before clinical diagnosis of recurrence. Only 3 patients exhibited such a pattern with CA 19-9. CONCLUSIONS: CA 72-4 is a reliable marker in gastric cancer. Postoperative serial sampling of CA 72-4 may facilitate early identification of recurrences.

Adenocarcinoma↗
PubMed1995

Extracorporeal pneumoperitoneum access bubble for endoscopic surgery.

The extracorporeal pneumoperitoneum access bubble (EPAB) creates a transparent extension of the pneumoperitoneum and has been developed to facilitate large organ extraction and tissue approximation in patients undergoing endoscopic surgical procedures. When fully deployed, the EPAB excludes the abdominal parietes from the emergent organ and dilates the exit wound by an average of 48.5%, irrespective of its location. It thus eliminates the problems of contamination and tumor seedling implantation during the removal of resected organs, aside from expediting the extraction. The operating version of the EPAB enables the introduction of the surgeon's or assistant's hands or instruments into the bubble and thence into the peritoneal cavity without deflation of the pneumoperitoneum. By this means, it reduces the technical difficulties required to dissect organs and achieve reconstruction by hand suturing or stapling.

Animals↗
PubMed1995

Visual Displays and Visual Perception in Minimal Access Surgery.

Visual perceptual processing underlies safe execution of endoscopic surgery. This review deals with the limitations of the present visual display technology used in endoscopic surgery with reference to the normal direct stereoscopic vision and pints to the research and development needed in this important technological and psychomotor aspect of endoscopic surgery. Eyeball movements (saccadic and smooth pursuit), visual cues (stereoscopic and monoscopic), accommodation, individual visual attributes, and the display technology itself are all important. Monocular depth cues are degraded by the cureent display systems, and technological advances in this are will improve perceptual processing and reduce both fatigue and human error during endoscopic interventions. Depth perception can be improved by alternative techniques to three-dimensional imaging such as the VISTRAL system and the Suspended Image System based on projection of image by parabolic mirrors and advanced beam spitter technology.

Journal Article↗
PubMed1995

Clamping the small intestine during surgery: predicted and measured sealing forces.

During bowel surgery it is often necessary to occlude the bowel using clamps. Occlusion occurs in two stages: approximation of bowel internal surfaces followed by sealing which is necessary to prevent seepage. The occlusive force at both stages depends on the luminal pressure, the latter stage requiring greater force than the former. The difference in luminal pressure across the sealing line results in a slipping force which is resisted by friction between the bowel and the clamp jaw surfaces. A theoretical model was developed to describe these forces and the predicted values obtained from this model were compared with direct measurements carried out on porcine bowel samples in a test rig. It was found that the measured approximation force was between 25 and 50 per cent of the maximum theoretical values and that sealing without seepage requires a clamp force of about ten times the approximation force. Using these results and known intraluminal pressures in the human gastrointestinal tract, a bowel clamp must apply around 7 N to prevent seepage and the coefficient of friction between clamp and bowel should be between 0.6 and 0.9.

Animals↗
PubMed1995

Detachable clamps for minimal access surgery.

A detachable clamp and applicator have been developed for use in minimal access surgical operations involving hollow visceral transection and anastomosis. The clamp has parallel jaws which ensure uniform distribution of the occlusive force. Following application on the bowel, the clamp is released from the applicator, thus freeing the access port. On completion of the anastomosis, the clamp is docked to the applicator, its jaws opened for release from the bowel and then closed prior to removal. The jaws of the clamp are kept closed by a pseudoelastic nickel-titanium (NiTi) alloy spring which imparts advantageous force characteristics when compared to stainless steel. The excellent holding and atraumatic characteristics of the detachable clamp have been confirmed by use in laparoscopic and thoracoscopic surgery on the gastrointestinal tract.

Colectomy↗
PubMed1995

Laparoscopic management of cancer patients.

All the reported experience indicates that laparoscopic staging of tumours provides additional information to the preoperative work-up. Its diagnostic yield is enhanced by contact ultrasonography. Staging laparoscopy may avoid needless laparotomy and permits palliative surgical treatment, bypass and resection. The major controversy concerns laparoscopic ablative procedure for potentially curative cancer in view of the potential but unproved risk of tumour dissemination and inadequate resection. Until further information becomes available from experimental investigations and centralized clinical studies, laparoscopic curative resections should not be performed routinely. Laparoscopic or retroperitoneoscopic lymphadenectomy appears to be useful by documenting node positive disease. Laparoscopic hepatic cryotherapy with insulated needle probes has the potential for control of secondary hepatic disease not amenable to surgical resection.

Biliary Tract Neoplasms↗
PubMed1995

Laparoscopic and thoracoscopic antireflux surgery.

Despite new effective drugs, like omeprazole, reducing gastric acid output and relieving gastro-oesophageal reflux disease (GERD) symptoms in most patients, there are still clear indications for surgical treatment of this chronic disease. The main indications are failure to control symptoms by medical treatment, noncompliance to medication and development of complications. Recent developments in minimal access surgery have modified the surgical approach to the treatment of GERD. The antireflux surgical procedures can be endoscopically performed reproducing all the essential component steps of the equivalent open operations, but with all the advantages of minimal access surgery. The fundoplication procedures are mainly performed laparoscopically and the thoracoscopic approach is chosen in patients with short oesophagus, morbid obesity or other contraindications to the laparoscopic approach. The short-term results of endoscopic antireflux surgery are at least as good than after open surgery. A review on the laparoscopic and thoracoscopic antireflux procedures is presented.

Endoscopy↗
PubMed1995

Thoracoscopic management of thoracic duct injury.

Thoracotomy has long been the conventional surgical approach in dealing with chylothorax due to thoracic duct injury which has been refractory to conservative treatment. The development of thoracoscopic access provides an alternative means of dealing with thoracic duct injuries thereby reducing the morbidity from thoracotomy and prolonged chylous leak. It will encourage earlier intervention in thoracic duct injury.

Adenocarcinoma↗
PubMed1994

Laparoscopic prosthesis fixation rectopexy for complete rectal prolapse.

Five women aged 64-81 years with complete rectal prolapse and incontinence were treated by laparoscopic mobilization of the rectum and posterior fixation to the presacral fascia using Marlex mesh. Mobilization was carried out with standard straight laparoscopic instruments in the first two patients (operating times 3.5 and 4.5 h) and with coaxial curved instruments and ultrasonic dissection in the succeeding three (operating times 2.5, 2.0 and 2.5 h). Restoration to full continence (grade 1) was observed in two patients and to grade 2 in a further two. No recurrence of the prolapse occurred during follow-up of 4-27 months.

Aged↗
PubMed1994

Comparative study of the holding strength of slipknots using absorbable and nonabsorbable ligature materials.

The holding and tensile characteristics of five extracorporeal slipknots in relation to absorbable and nonabsorbable ligature materials have been evaluated in a standardized in vitro test rig. The knots studied: Tayside, Roeder, Melzer (modified Roeder), Cross square, and Blood knots were tied with the following materials: silk, polyamide, Dacron, polydioxanone (PDS), and lactomer (Polysorb). Following construction and slippage (run down) to a fixed-diameter loop around a cylinder, the knots were locked (tightened) using a standardized force after which they were removed from the test rig and subjected to holding strength (force required to induce reverse slippage) and other tensile characteristics (stress, strain, elasticity) by a tensiometer. Analysis of the data has demonstrated the following: (1) The safest slip knots (resist slippage) are the Tayside, Melzer, and Roeder knots tied with lactomer and Dacron. (2) The holding strengths of the Cross square and Blood knots are weak with all ligature materials tested. (3) Polydioxanone is a safe ligature material for the Melzer and Tayside but not the Roeder knot. (4) Extracorporeal slipknots tied with silk and polyamide are less secure than the equivalent knots tied with Dacron, lactomer, and polydioxanone.

Insect Proteins↗
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↗
PubMed1994

Slicer and tissue retrieval system for excisional endoscopic surgery.

Extraction of large specimens risks detachment of malignant cells within the peritoneal cavity and contamination of the parieties with resultant seedling implantation at the access wounds. Therefore, extraction is best conducted through a rip-proof sleeve-retrieval system which creates a "third space" in which the specimen can be sliced under visual control. Slicing of tissue is preferable to morcellation or disintegration since it preserves the structural integrity of the tissue and thereby does not jeopardize histopathological examination and staging of excised tumors. Of the two types of tissue-slicing mechanisms investigated, the compression-moving blade system (CMB) was found to be superior to wire-cutting devices. A prototype CMB slicer has been developed which has been tested experimentally and is currently undergoing clinical evaluation.

Animals↗