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Biomedical subjects

G Buess

Publications and source records attributed to G Buess.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Local therapy of rectum carcinoma. A prospective follow-up study].

Local therapy of rectal carcinoma with the method of TEM was performed in 98 patients during the period from August 1, 1989 to January 31, 1994. 56 of the patients had pT1, 27 pT2, and 15 pT3 tumours. There was no lethality. The rate of complications, which required operative intervention, was 8%. No lymph node metastases were found in the specimens of the patients with pT1 tumours, who were re-resected, because the margin of the primary specimen were judged to be not free of tumour. In the specimens of the re-resected patients with pT2 carcinomas, lymph node involvement was more common than remnants of the primary tumour. Two of the patients with local therapy of pT1 low-risk carcinomas developed a recurrence so far. A secondary procedure for cure according to oncologic criteria could be performed in both cases. In selected cases the local therapy of rectal carcinoma avoids the high morbidity and mortality of the classical operation. Live quality will be improved, especially if an artificial anus can be avoided. In case of a recurrence the chance of a secondary procedure for cure is not to be underestimated.

Adult↗
PubMed1996

[Local therapy of early rectal carcinoma with curative intent: implications for a change in oncologic strategy].

Patients with pT1 low-risk rectal carcinomas seem to be overtreated by a classical radical operation. A total of 170 patients with rectal carcinomas were locally treated with the transanal endoscopic microsurgery (TEM) technique. Four of the group with pT1 low-risk tumours with local therapy developed a recurrence, three of whom underwent a curative secondary procedure, bringing the failure rate to one out of 81. Two recurrences were diagnosed among the 22 patients who were re-resected after local treatment in stage pT1 low risk. Both patients died of the tumour disease, another due to dehiscence of the suture, bringing the failure rate in the re-resected group to three of 22.

Aged↗
PubMed1995

Local excision of rectal tumours.

Local excision of colorectal tumour may be palliative or curative. Recent advances in minimal access techniques have allowed curative excision to be offered to a wider range of patients. Absolute indications for potentially curative local excision include mobile tumours, T1 tumours (assessed by ultrasonography), well or moderately differentiated histology (determined by biopsy) and tumour size less than 3 cm. Relative indications include T2 and T3 tumours (by ultrasonography), poorly differentiated histology (by biopsy) and tumour size greater than 3 cm depending on patient fitness. The rationale for these recommendations is described in detail.

Colorectal Neoplasms↗
PubMed1995

Ports, Trocars/Cannulae, and Access Techniques.

One of the keys to safe laparo-endoscopic surgery is an expeditious, reliable, and safe access to the operative field. Aside from appropriate surgical technique, the technology of trocars, cannulae, and other endoscopically guided insertion techniques plays a decisive role for safe identification of and access to the peritoneal cavity. This report takes a close look at critical features of trocar and cannula design for blind insertion with the focus on the biomechanical principles involved in traversing the abdominal wall. Particular attention has been paid to techniques minimizing the risk of accidental injury to major vessels, intestine, and other important structures. The principle of controlled visualized access led to several developments in the field of trocars, cannulae, and puncture techniques. Aside from blind and open access with the Veress needle, conventional trocars and cannulae, a selected variety of endoscopically assisted ports such as the optical Veress needle, optical trocars and optical scalpel, and a vacuum-supported access system are described in detail.

Journal Article↗
PubMed1995

Endoscopic Approach.

The increasing use of the laparoscopic approach in colorectal surgery depends not only on the indications but also on technological development. Better visualization of the operative field is available using a three-chip camera or three-dimensional system. Alternative port positionings together with curved instruments increase the degree of freedom during operation. Complex laparoscopic procedures need highly specific instruments. We have developed atraumatic bowel graspers, different types of retractors, and innovative combination instruments. OREST II, a new multipurpose system that assists the organization of laparascopic surgery is described.

Journal Article↗
PubMed1995

Endoscopically controlled trocar and cannula insertion.

One of the keys to safe laparoscopic or thoracoscopic surgery is an expeditious and reliable access to the region of interest. To minimise the risk of accidental injury to major vessels, lung, intestine and other important structures the principle of controlled visualised access has been advocated. This has led to several developments in the field of trocars, cannulae and puncture techniques. Examples are the insertion of a needle scope into a Veress needle, complex access cannulae and our new principle of using an "optical scalpel". The direct visualisation of an active, controllable penetration of the abdominal wall is expected to become indispensable. A selected variety of endoscopically assisted trocar and cannula systems such as the "windowed trocar", the "optical trocar", the "Visiport" and the "optical scalpel" are described.

Catheterization↗
PubMed1995

OREST II--ergonomic workplace and systems platform for endoscopic technologies.

Endoscopic interventions require a multitude of technical devices, like gas-insufflators, cameras, light sources, high-frequency scalpels and others. The devices available today represent stand-alone "function-insulas" from the view-point of systems technique. They have to be placed in the operating theatre and set-up right before each specific intervention. From each of these single devices supplies, cables and hoses lead to the body of the patient and have to be connected on both sides within the sterile and the non-sterile field. This not only requires a long setup time in the OR but also restricts the mobility of the operative personnel. Besides the ergonomic and the hygienic weakness of the contemporary solution, significant functional problems limit the efficiency of the OR environment. One of the major drawbacks lies in the lack of direct control of the devices by the surgeon and the confusing display of parameters and technical status. Against this background the systematic revision of the current endo-surgical workplace appears to be a major requirement for further technical and surgical progress. As a result of close cooperation between surgeons and engineers a systems workplace for minimally invasive surgery, OREST, has been developed and clinically tested. It integrates all devices into a mobile cabinet. The single devices are connected to a central computer and can be remote controlled directly by the surgeon from the table. A special display continuously informs about the system status. The lines and cables are guided into the sterile field by means of a swivel arm from one side of the patient. Multi-plugs are used to connect all lines at a central terminal within the sterile area. Clinical application of the first prototype OREST I started in 1993. OREST II is now available as a series product. Further development is focused on the integration of advanced sub-systems like tactile devices and advanced vision system.

Computer Systems↗
PubMed1994

Indications and technique for TEM (transanal endoscopic microsurgery).

Transanal Endoscopic Microsurgery (TEM) was introduced into clinical practice by the Buess group in 1983. Since then vast experience has been gained in removing tumours of the rectum by the operative rectoscope. Though the indication in benign lesions for TEM as a local resection therapy is undisputed, the indication for resection of T1 or advanced carcinomas has to be evaluated. By using a 40 mm operating rectoscope sealed with a gastight working insert to prevent pressure loss after creation of a pneumorectum and a stereoscopic optic with sixfold magnification, exact visualisation of a rectal tumour can be achieved. The insertion of endoscopic surgical instruments like the high frequency knife, forceps, scissors, and suction device allows precise excision of the lesion as well as suture closure of the wound. Recently a bipolar multifunctional combination instrument has been developed for more precise dissection, less blood loss and shorter operation times.

Anal Canal↗
PubMed1994

TEM results of the Tuebingen group.

From August 1st 1989 to May 1st 1993, 190 rectal adenomas and 75 carcinomas were locally excised with the TEM technique. The mortality was 0.4%, the rate of complications which required surgical re-intervention was 3% in adenomas and 8% in carcinomas. The final histology of the removed carcinomas revealed 44 pT1, 23 pT2 and eight pT3 stages. In two of the eight re-resected patients with pT1 low-risk tumours, residual primary tumour but no lymph node metastases were found. In contrast to this, three of the eleven re-resected patients with pT2 low-risk tumours had already developed lymph node metastases. After an average follow-up time of 14 months, two recurrences were observed in the group of the only locally treated patients with pT1 low-risk carcinomas. Both underwent a secondary procedure for cure but in late tumour stages. No recurrence was diagnosed so far among the re-resected patients.

Adult↗
PubMed1994

Automated processing of endoscopic surgical instruments.

This paper deals with the requirements for automated processing of endoscopic surgical instruments. After a brief analysis of the current problems, solutions are discussed. Test-procedures have been developed to validate the automated processing, so that the cleaning results are guaranteed and reproducable. Also a device for testing and cleaning was designed together with Netzsch Newamatic and PCI, called TC-MIC, to automate processing and reduce manual work.

Automation↗
PubMed1994

Technique of endoscopic mediastinal dissection of the oesophagus.

Conventional transhiatal dissection of the oesophagus is usually performed without visual control. The attendant danger of this is that complications such as bleeding and tracheal lesions may be overlooked. This problem can be avoided by the use of an endoscopic operation system. This report describes a new technique of endoscopic microsurgical dissection of the oesophagus (EMDOE) and the results of the first 35 cases. Under visual control with a specially designed mediastinoscope the soft tissue surrounding the oesophagus is carefully dissected, and the oesophageal blood vessels can be safely exposed, coagulated and divided. The dissection begins cervically and proceeds along the oesophagus down to the oesophagocardiac junction. A simultaneously working abdominal team helps remove the oesophagus, which is then replaced by a stomach tube. Although the method is still under evaluation, results to date have been especially good for small distal tumors, especially adenocarcinomas.

Adenocarcinoma↗
PubMed1994

Thoracoscopic oesophagectomy with intrathoracal stapled anastomosis.

Techniques for intrathoracal stapler anastomosis under thoracoscopic control were studied and developed in an experimental program. Since this procedure is possible from two directions, both directions were evaluated. Two different techniques, a transoral and a transhiatal, resulted. For the transoral technique the stapler is inserted from above. The anvil, which is connected to a wire, is drawn into the abdomen together with the distal oesophagus. Retracting the wire pulls both the anvil and the stomach tube up into the thorax after the insertion of the anvil. The second technique requires a special attachment to introduce the anvil transhiatally into the thorax and into the oesophageal stump. The gastric tube is pushed into the thorax by the stapler gun, which is inserted into the stomach through an antrostomy. The insertion of the anvil into the oesophageal stump can also be achieved with the support of a flexible endoscope including a polyp snare.

Anastomosis, Surgical↗
PubMed1994

Future trends in endoscopic suturing.

This paper deals with future aspects and developments in endoscopic sutures, needles, needle drivers, and sewing devices. Shape memory alloys such as superelastic nickel-titanium can be used for surgical needles and hingeless needle drivers. A sewing device consists of a T-Needle which can be shuttled between the jaws of specially designed instruments. The jaws possess small elements that grip the needle tips. The "Needle Rotor" facilitates intracorporeal swivelling and positioning of the needle because one jaw can be moved longitudinally over the other. A new "cutting knot pusher" permits immediate cutting of a slip knot subsequent to tightening.

Anastomosis, Surgical↗
PubMed1993

New technique for sigmoid colectomy.

A combination of laparoscopic and rectoscopic procedures has enabled complete resection of the sigmoid colon and eliminated the need for minilaparotomy when constructing the anastomosis or withdrawing the specimen. This combined procedure was performed in different ways in a series of animal models until the definitive technique had been standardized. These techniques were then successfully used in 15 consecutive medium-sized pigs. Histological evaluation of the specimens, including the anastomosis (examined 2-3 weeks after operation) confirmed the efficacy and safety of the method.

Anastomosis, Surgical↗
PubMed1993

Review: transanal endoscopic microsurgery (TEM).

Transanal endoscopic microsurgery (TEM) is performed with the use of a complex operative system, which allows the application of all surgical techniques for dissection and suturing inside the rectal cavity up to a height of 20 cm from the dentate line. Gas dilation and stereoscopic vision give an optimal overview during the procedure. In sessile adenomas and carcinomas within the region of the extraperitoneal rectum, full thickness excision is the standard procedure. The postoperative course is completely painless in all excisions at some distance from the dentate line. The complication rate is low compared with other procedures and the recurrence rate in sessile adenomas (3.5%) lower than in conventional surgery as a result of the precise dissection which is possible under the magnified stereoscopic vision. In PT1 low risk cancer we found one recurrence in 29 patients.

Adenoma↗