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Biomedical subjects

D Mutter

Publications and source records attributed to D Mutter.

At least 37 records · Page 2Linked to original sources
PubMed2000

Nitrous oxide fraction in the carbon dioxide pneumoperitoneum during laparoscopy under general inhaled anesthesia in pigs.

UNLABELLED: During prolonged laparoscopy, the diffusion of other gases in the carbon dioxide (CO(2)) pneumoperitoneum may lessen its safety. Nitrous oxide (N(2)O)/CO(2) gas mixtures may become hazardous with regard to gas embolization and fire risk. We therefore evaluated the kinetics of pneumoperitoneal intrusion of N(2)O. In five anesthetized domestic pigs, controlled ventilation, with an initial fraction of inspired oxygen = 1.0, was adjusted to keep ETCO(2) pressure between 35 and 45 mm Hg. The peritoneum was insufflated with CO(2) to a pressure of 12 mm Hg, which was maintained throughout the procedure. T0 was defined as the time when N(2)O was introduced in the breathing circuit (N(2)O end-tidal fraction = 66%). Gas samples (10 mL) from the pneumoperitoneum were analyzed every 10 min after T0. The N(2)O concentration was measured by using capillary gas chromatography coupled with mass spectrometry. Percentages of N(2)O in the CO(2) increased with time (t) according to the ideal equation: N(2)O((t)) = 66 (1 - exp(-0.005t)). In the peritoneal cavity, <2 h were required for the N(2)O to reach the concentration of 29%, which can support combustion. Eight hours to 10 h after T0, the intraperitoneal N(2)O fraction approaches the level of the N(2)O end-tidal fraction. Options to prevent accumulation of N(2)O are suggested. IMPLICATIONS: Pig models were used to evaluate the time course of nitrous oxide (N(2)O) diffusion in the pneumoperitoneum during nitrous oxide/oxygen anesthesia. Although peritoneal N(2)O concentration approaches the end-expiratory value after 8-10 h, it reaches 29% within 2 h. At this level, N(2)O is known to support combustion. This N(2)O pollution should be prevented.

Anesthesia, Inhalation↗
PubMed2000

Assessment of telemedicine in surgical education and patient care.

OBJECTIVE: To analyze the value of teleconferencing for patient care and surgical education by assessing the activity of an international academic network. SUMMARY BACKGROUND DATA: The uses of telemedicine include teleeducation, training, and consulting, and surgical teams are now involved, sharing diagnostic information and opinions without the need for travel. However, the value of telematics in surgery remains to be assessed. METHODS: During a 2-year period, weekly surgical teleconferences were held among six university hospitals in four European countries. To assess the accuracy of telediagnosis for surgical cases, 60 randomly selected cases were analyzed by a panel of surgeons. Participants' opinions were analyzed by questionnaire. RESULTS: Seventy teleconferences (50 lectures and 271 case presentations) were held. Ninety-five of the 114 participants (83.3%) completed the final questionnaire. Eighty-six percent rated the surgical activity as good or excellent, 75.7% rated the scientific level as good or excellent, 55.8% rated the daily clinical activity as good or excellent, and 28.4% rated the manual surgical technique as good or excellent. The target organ was identified in all the cases; the organ structure and pathology were considered well defined in 93.3%, and the fine structure was considered well defined in 58.3%. Diagnosis was accurate in 17 cases (28.3%), probable in 25 (41.7%), possible but uncertain in 16 (26.7%), and not possible in 2 cases (3.3%). Discussion among the remote sites increased the rate of valuable therapeutic advice from 55% of cases before the discussion to 95% after the discussion. Eighty-six percent of the surgeons expressed satisfaction with telematics for medical education and patient care. CONCLUSIONS: Participant satisfaction was high, transmission of clinical documents was accurate, and the opportunity to discuss case documentation and management significantly improved diagnostic potential, resulting in an accuracy rate of up to 95%. Teleeducation and teleconsultation in surgery appear to be beneficial.

Cost-Benefit Analysis↗
PubMed2000

Dual effect of laparoscopy on cell-mediated immunity.

Laparoscopic influence on cell-mediated immunity and tumour evolution is controversial. The objective of the present study was to assess tumour growth and immune patterns after laparoscopy on an experimental study. Lewis rats, bearing an intrapancreatic ductal carcinoma randomly underwent one of the following 2-hour procedures: anaesthesia, laparotomy or CO(2) pneumoperitoneum. Cell-mediated immunity was investigated through determination of serum IL1beta concentrations by ELISA and TNFalpha, IL6 and iNOS gene transcriptions in blood white cells and peritoneal cells by RT-PCR 1 day after operation. Tumour growth and spread patterns were assessed on anatomopathological examination 2 weeks after surgery. Tumour growth and spread were unaffected no matter what procedure was applied, but port-site seeding occurred in half of the cases undergoing laparoscopy. No significant change in acute-phase protein response, represented by IL1beta serum concentration, was found after laparoscopy. TNFalpha, IL6 and inducible NO synthase gene transcriptions were enhanced in blood white cells and depressed in peritoneal immune cells after laparoscopy. In our experimental conditions, cell-mediated immune response to CO(2) pneumoperitoneum seems to be a good systemic immune activation and a less acute peritoneal immune response as opposed to control laparoscopy. This early impairment of peritoneal macrophage immune activity, observed after a long-lasting CO(2) pneumoperitoneum, might be responsible for the high rate of port site recurrence.

Animals↗
PubMed2000

Knowledge and acceptance of telemedicine in surgery: a survey.

A questionnaire was sent to the chief surgeons at 141 Swiss hospitals to evaluate their knowledge and acceptance of telemedicine in surgery. The response rate was 69%. Ninety-three per cent of all surgical departments used computer technology, 85% regularly used the Web and 88% had an internal hospital network. ISDN lines were used in 58% of the participants' hospitals. While 35% of respondents had participated at least once in networking, only 8% regularly used telemedicine. The opinion was that access to therapeutic advice (87%) was a better use of telemedicine than was obtaining a primary diagnosis (24%), although the majority accepted the principle of making (91%) and receiving (94%) a remote diagnosis. The survey suggested that surgeons are interested in telemedicine and open to its development, although their experience and knowledge are limited. Therefore, telemedicine in surgery may be advanced by creating surgical networks for teleconsultation and tele-education.

Health Knowledge, Attitudes, Practice↗
PubMed2000

[Surgical treatment of acute sigmoiditis].

Virtually unknown at the beginning of the century, diverticulosis has become very prevalent in western countries. The natural history of the disease is notable for its acute, sometimes recurrent, attacks of diverticulitis and the significant risk of serious complications : abscess, fistula, peritonitis. CT scanning predominates in the diagnostic evaluation. It can provide both diagnostic and prognostic information. Most mild attacks of diverticulitis respond well to medical therapy while surgical treatment is indicated in the complicated forms of the disease. Surgical therapy has gradually evolved from a complicated three stage approach to two-staged, single-staged, or even minimally invasive procedures. The current trend is to intervene surgically well after the resolution of the acute attack. To achieve this, liberal use of percutaneous drainage of collections and medical treatment are advocated. The decision to perform prophylactic sigmoid resection must be based on a balance assessment of risk factors including age, severity of attacks and their recurrence.

Acute Disease↗
PubMed2000

Virtual university applied to telesurgery: from teleeducation to telemanipulation.

UNLABELLED: PROBLEM/BACKGROUND: In order to improve patient care by minimal invasive surgery (MIS), we perfected a Virtual TeleSurgical University that allows for teleeducation, teleconcertation, surgical planning and telemanipulation, through new Virtual Reality and multimedia systems. TOOLS AND METHODS: The organization of this innovative school was federated around three major research programs. First, the TESUS program focused on the teletransmission of medical information, allowing for videoconferencing around the world and telementoring. Next, the WeBS-Surg program is a multimedia continuous surgical education system on internet, that allows for teleeducation and teleconcertation between world experts in MIS. Then, the MASTER program (Minimal Access Surgery by Telecommunications and Robotics) allowed the development of the third millenium Operating room. It included Virtual Reality systems that delineate automatically anatomical and pathological structures of a patients from him CT-scan, and that allow for an interactive surgical planning and force-feed-back simulation. It also included a telesurgical robot named Zeus controlled by surgeons through telemanipulation system. RESULTS: Tests and validation shows that all these systems improved all steps of the surgical procedure: preoperatively due to a better continuous education and a computer assisted surgical planning, and peroperatively due to teleconcertation, telementoring and telemanipulation systems. CONCLUSION: Revolutionary tools for minimal invasive surgery learning, planning and performing are all ready available. These tools represents the first prototype of the computer assisted tele-robotical surgery that will be the future of surgery.

Computer Simulation↗
PubMed1999

Endoscopic surgery: ideal for endocrine surgery?

The laparoscopic approach of endocrine tumors is recent, the first reported resection of an adrenal gland in 1992. It represents a revolution in endocrine surgery equivalent to that observed in general surgery after the first cholecystectomy was performed in 1987. This new approach needs evaluation in terms of feasibility, indications, safety, and surgical procedure to define its potential advantages. The surgical technique and operative approaches of laparoscopic adrenalectomies are at the present time well defined and mostly accepted. Pancreatic approaches and resections, thyroidectomies, and parathyroidectomies are more confidential and performed only by rare teams. Nevertheless, the development of this technique is ineluctable. The spread of this technique, partly due to the increased quality of the technologies available, especially cameras, encounter a major brake that limits its generalization: If general surgeons commonly perform laparoscopy in their daily practice, they treat few patients presenting endocrine disorders. On the other hand, endocrine surgeons to whom many patients are referred do not have regular videoscopic practice. Endocrine surgery benefit few patients for these reasons. An analysis of the present state of the art allows us to imagine the evolution and future of videoscopic endocrine surgery.

Endocrine Gland Neoplasms↗
PubMed1999

Increased tumor growth and spread after laparoscopy vs laparotomy: influence of tumor manipulation in a rat model.

BACKGROUND: The use of laparoscopy for assessment and treatment of malignant tumors remains controversial. The aim of this study was to evaluate the impact of tumor manipulation during laparoscopy compared with that of conventional laparotomy on growth and spread of an intraperitoneal tumor in the rat in a randomized, controlled trial. METHODS: Thirty 2-month-old male Lewis rats received a single-site intrapancreatic inoculation of a ductal adenocarcinoma. Fourteen days after cancer implanting, two groups of six animals each underwent a laparotomy (30 min 6 mmHg CO2 pneumoperitoneum). The tumor was manipulated in the one group, and exclusively visualized in the other. In two other groups, a midline laparotomy with (n = 6) or without (n = 6) tumor manipulation was performed. Animals in the control group (n = 6) underwent no procedure. Tumor volume, tumor mass, local regional invasion incidence, lymph node involvement, and liver and lung metastases were evaluated on 28-day tumors. RESULTS: No difference in tumor growth and spread was observed between laparoscopy and laparotomy when tumor manipulation was not carried out. Tumor manipulation increased tumor growth significantly in the laparotomy group, but not in the laparoscopy one. Tumor metastases were correlated to tumor growth and increased significantly after manipulation in both groups. There was no port-site or conventional wound seeding in either the surgical procedure. CONCLUSIONS: This study showed that manipulation is the main factor acting on tumor dissemination in both laparoscopy and laparotomy. Laparoscopic surgery had a beneficial effect on local tumor growth compared with laparotomy in the case of tumor manipulation. This beneficial effect of laparoscopic surgery may be related to a better preservation of immune function in the early postoperative period.

Analysis of Variance↗
PubMed1999

[Experiences with adrenalectomy in 1997. Apropos of 247 cases. A multicenter prospective study of the French-speaking Association of Endocrine Surgery].

STUDY AIM: The aim of this prospective study conducted by the AFCE was to analyze the indications, approach and results of all adrenalectomies performed during the year 1997 in 17 centers, active or specialized in endocrine surgery. PATIENTS AND METHODS: During 1997, adrenalectomy was performed in 247 patients, 149 men and 98 women (mean age: 51 years). The lesion was located in the right side in 166 patients, in the left side in 99, in both sides in 28 patients and ectopic in four patients. Pheochromocytomas (n = 61), Conn adenomas (n = 50) and Cushing syndrome lesions (n = 48) were the most frequent in this series. Laparoscopic adrenalectomy was performed in 172 patients (70%) through a transperitoneal approach in all cases except one, and by 'open' surgery in 75 patients (30%). RESULTS: In patients operated on by the laparoscopic approach, the mean duration of surgery was 132 min, and there were peroperative complications in 15 patients (8.7%), mainly hemorrhages. Conversion rate into laparotomy was 7%. In the postoperative course, there were three reoperations and two deaths, an early one in a patient reoperated for bleeding and a very late one in relation with necrotising acute pancreatitis. Mean duration of hospitalization was 5.8 d. Mean tumoral size was 49 mm. In patients operated on by 'open' surgery, the mean duration of surgery was 148 min. There was a postoperative complication in eight patients (10.6%), mostly hemorrhages, and two intraoperative deaths in relation with uncontrollable bleeding. Mean duration of hospitalization was 11 d. Mean tumoral size was 72 mm. CONCLUSION: Laparoscopic adrenalectomy is now indicated for the majority of adrenal tumors. Several complications observed in this series were related to the learning curve in several centers. Laparoscopic adrenalectomy is the 'gold standard' in uni- or bilateral benign tumors no larger than 6 or 7 cm. 'Open' surgery is indicated in malignant tumors, especially in adreno-cortical carcinomas, and in all large tumors.

Adenoma↗
PubMed1999

[The virtual university applied to telesurgery: from tele-education to telemanipulation].

The advent of new computer technologies can appear as a revolution in surgical teaching, as well as in the planing and realization of surgical procedures. The introduction of a camera into the body of a patient, allowing the visual display of the operative procedure through the use of a miniaturized camera, constitutes the greatest change that the surgical world has experienced at the end of this century: mini-invasive surgery is born. This revolution also predicts further changes: the development of telecommunication devices applied to medicine (tele-education, tele-training, tele-mentoring, tele-proctoring and tele-accreditation), constitutes the basis of cybersurgery or virtual reality allowing the merging of the concepts of tele-presence and telemanipulation. These new concepts were developed at the European Institute of TeleSurgery at Strasbourg. The TESUS project developed the use of surgical images and data transmission through the realization of international multi-site video conferences between surgeons. The WEBS project created the first virtual university concept by placing surgical techniques at the surgeon's disposal through the Internet. The HESSOS project uses virtual reality as a surgical simulation system. The MASTER project allows the development of the concept of distant telemanipulation. It is now possible to face surgical teaching outside of the restricted University framework, and to conceive teaching on a world-wide level, offering the practitioner unimaginable possibilities of formation, training and the planning of surgical procedures.

Computer-Assisted Instruction↗
PubMed1999

[Telematic and surgery: methods, terminology and instructions].

BACKGROUND: Telematic is the application of computer technology in modern telecommunication. Telemedicine will be of growing importance in the international collaboration in surgery. OBJECTIVE: Review of the different telematic applications for surgery and presentation of technology and tools. Practical user's guide. METHOD: Analysis of our international network of telesurgical staff meetings between 6 University Hospitals. Review of the situation of telemedicine in Switzerland and around the world. RESULTS: After performing some comparative tests we chose to work with 6 ISDN channels at the world wide standard H.320 (rate of 384 Kb/s) which is widely available in Switzerland and around the world. Technical options, market opportunities and relationship between needs and goals of telemedicine are presented on a user point of view. DISCUSSION: More than 70 telesurgical staff meetings allowed us to get an overview of this technology, in order to benefit of telemedicine applications for teaching and clinical use. Important factors are the analysis of needs and goals prior to the teleconference. CONCLUSION: Consultation, second opinion, teaching and training should be new clinical applications of telemedicine, leading to an increase of surgical quality control in Europe and in the world.

Computer Communication Networks↗
PubMed1999

Laparoscopic bilateral adrenalectomy in a child.

Laparoscopic adrenalectomy is an established technique--in adults. This report describes a bilateral laparoscopic adrenalectomy in a child. As in adults, it indicates that the technique is superior in anatomic exposure and postoperative recovery, and is well suited for children.

Adolescent↗
PubMed1999

[The Virtual University applied to telesurgery: from tele-education to tele-manipulation].

The advent of new computer technologies appears as a revolution of surgical teaching, as well as the planning and realisation of surgical procedures. The introduction of a camera into the body of a patient, allowing the visual display of the operative procedure through the use of miniaturised camera constitutes the greatest alteration that the surgical world has experienced at the end of this century: mini-invasive surgery is born. This revolution was announces further changes: the development of telecommunication devices applied to medicine (tele-education, teletraining, telementoring, teleproctoring and tele-accreditation) constitutes the basis of cybersurgery or virtual reality allowing the merging of the concepts of telepresence and telemanipulation. These new concepts were developed at the European Institute of TeleSurgery of Strasbourg. The TESUS project developed the use of surgical images and data transmission through the realisation of international multi-site video conferences between surgeons. The WEBS project created the first Virtual University concept placing surgical techniques at the surgeon's disposal through Internet. The HESSOS project uses virtual reality as a surgical simulation system. The MASTER project allows to develop the concept of distant telemanipulation. It is now possible to face surgical teaching outside of the restricted University frame and to conceive teaching on a world level, offering to the practitioner unimaginable possibilities of formation, training and planning of surgical procedures.

Education, Medical↗
PubMed1999

Laparoscopic management of operative vena cava injury.

Major vascular injury can result from trocar placement, but it is a rare event during an intra-abdominal laparoscopic procedure. The authors report a major vena cava injury that occurred during a right adrenalectomy. The injury was managed entirely laparoscopically. Management of a major vascular injury occurring in such circumstances requires appropriate instruments and equipment, including a vascular clamp and good suction. Conversion to an open procedure is recommended if the injury cannot be safely resolved laparoscopically.

Adenoma↗
PubMed1998

General oncologic effects of the laparoscopic surgical approach. 1997 Frankfurt international meeting of animal laparoscopic researchers.

The results from the majority of the reviewed studies support the hypothesis that abdominal surgery, performed via either a large incision or CO2 pneumoperitoneum, systemically encourages tumor growth in the postoperative period. A full laparotomy incision appears to have a significantly greater effect than CO2 pneumoperitoneum on postoperative tumor growth. Whether the large tumor observed in the surgical groups are the result of increased tumor cell proliferation or diminished tumor cell death remains unclear. There is some evidence pointing to both mechanisms. The loss of the postoperative tumor growth differences between the open and pneumo animals in the athymic mouse experiment suggests that cell-mediated immune function plays a role in tumor containment. The proliferation study results, however, suggest that other stimulatory influence(s) are also at work. Clearly, much research needs to be done regarding the etiology of these tumor growth differences. Other tumor cell lines need to be studied, and investigations regarding tumor growth in an intra-abdominal location need be performed as well. This body of research suggests that the manner in which the surgeon gains access to the abdominal cavity may have an impact on the propensity of tumor cells to implant, survive, and grow in the period immediately after surgery. If true, this may be the most compelling justification for the use of minimally invasive techniques for the curative resection of malignancies. However, it remains to be proven that human tumors will demonstrate differences in tumor growth similar to those noted in some of these animals models. Furthermore, it is not all clear that slight differences in tumor growth postoperatively will translate into significant differences in long-term survival or recurrence rates. At first glance, the existence of port-site tumors would appear to contradict totally the conclusions of many studies discussed in this synopsis. If laparoscopic methods are associated with decreased rates of tumor growth and establishment, then why do port-site tumors form? This is a complex issue calling for discussion that goes far beyond the scope of this article. However, several brief comment on this topic follow. The etiology of port tumors is unknown, although traumatization of the tumor during mobilization, resection, or removal is likely to play a significant role in the liberation of tumor cells from the primary. A relatively small protective benefit, in terms of slower tumor growth rates in laparoscopic patients, will likely not be sufficient to prevent a large inoculum of viable tumor cells in an abdominal wound from establishing a metastasis. Furthermore, as suggested earlier, the systemic effects on tumor growth may be different from the local (i.e., intra-abdominal or abdominal wound) effects. Finally, the true incidence of port tumors remains unknown. It has not been definitively established that the laparoscopic wound tumor incidence is significantly higher than the open rate, although this is the assumption of most surgeons. Several relatively large recently published laparoscopic series have reported port tumor incidences of 0 to 1.2%, which is in the same "ballpark" as the 0.6 1.0% abdominal wound tumor incidences mentioned in several open colectomy series. Clearly, much more research in this area is needed to understand port tumors better and to reconcile the port tumor results with the systemic tumor growth benefits that may be associated with minimally invasive methods.

Animals↗
PubMed1998

[A new concept in surgery of the digestive tract: surgical procedure assisted by computer, from virtual reality to telemanipulation].

Surgical simulation increasingly appears to be an essential aspect of tomorrow's surgery. The development of a hepatic surgery simulator is an advanced concept calling for a new writing system which will transform the medical world: virtual reality. Virtual reality extends the perception of our five senses by representing more than the real state of things by the means of computer sciences and robotics. It consists of three concepts: immersion, navigation and interaction. Three reasons have led us to develop this simulator: the first is to provide the surgeon with a comprehensive visualisation of the organ. The second reasons is to allow for planning and surgical simulation that could be compared with the detailed flight-plan for a commercial jet pilot. The third lies in the fact that virtual reality is an integrated part of the concept of computer assisted surgical procedure. The project consists of a sophisticated simulator which must include five requirements: a) visual fidelity, b) interactivity, c) physical properties, d) physiological properties, e) sensory input and output. In this report we describe how to obtain a realistic 3D model of the liver from bi-dimensional 2D medical images for anatomical and surgical training. The introduction of a tumor and the consequent planning and virtual resection is also described, as are force feedback and real-time interaction.

Anatomy, Cross-Sectional↗
PubMed1998

Value of microlaparoscopy in the diagnosis of right iliac fossa pain.

BACKGROUND: The possibility of performing minimally invasive exploration of the abdomen could avoid unnecessary appendectomies. Micro-optics and instruments of 2 mm in diameter allow this type of exploration, but the feasibility and the accuracy of the diagnosis resulting from this method have not been evaluated. METHODS: A prospective study of 36 patients (11 men and 25 women) operated on for acute right iliac fossa pain was carried out. The abdomen was explored with a 2 mm optic and with a 10 mm optic in order to characterize the aspect of the appendix. The results were compared with the postoperative pathologic findings of the appendix. RESULTS: The micro-optic procedure failed in 3 patients. The appendix was visualized in 26 patients: in 18 patients through the needle-optic alone, 8 patients requiring additional instruments. The appendix was visualized in all cases with the 10 mm optic. Appendectomy was performed in 34 patients: with microinstruments in 6, with 5 mm instruments in 26, and through a MacBurney incision in 2. The appendix was not removed in 2 patients. A correct diagnosis was made by microlaparoscopy and confirmed by the pathology in 21 patients (58%), made and confirmed in 32 patients with a 10 mm optic (89%). Minor complications included a cecal wall insufflation in 1 patient and a peroperative hemorrhage on a 2 mm port site in another with an uneventful postoperative course. One postoperative parietal hematoma required reoperating removal. No mortality was observed. CONCLUSIONS: The low quality of the image obtained with microlaparoscopy does not permit safely evaluating the aspect of the appendix in case of acute right iliac pain. This method is not recommended for routine abdominal exploration.

Abdomen, Acute↗