Prevention of radiation enteritis by intrapelvic breast prosthesis.

Pelvic malignancies frequently require post-operative radiation therapy that may induce small bowel damage at an incidence of 5-25%. Various surgical techniques have been reported to prevent acute and chronic radiation enteritis. This article describes the technical aspects of pelvic exclusion by an intrapelvic silicone breast prosthesis.

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.

Virtual reality applied to hepatic surgery simulation: the next revolution.

OBJECTIVE: This article describes a preliminary work on virtual reality applied to liver surgery and discusses the repercussions of assisted surgical strategy and surgical simulation on tomorrow's surgery. SUMMARY BACKGROUND DATA: Liver surgery is considered difficult because of the complexity and variability of the organ. Common generic tools for presurgical medical image visualization do not fulfill the requirements for the liver, restricting comprehension of a patient's specific liver anatomy. METHODS: Using data from the National Library of Medicine, a realistic three-dimensional image was created, including the envelope and the four internal arborescences. A computer interface was developed to manipulate the organ and to define surgical resection planes according to internal anatomy. The first step of surgical simulation was implemented, providing the organ with real-time deformation computation. RESULTS: The three-dimensional anatomy of the liver could be clearly visualized. The virtual organ could be manipulated and a resection defined depending on the anatomic relations between the arborescences, the tumor, and the external envelope. The resulting parts could also be visualized and manipulated. The simulation allowed the deformation of a liver model in real time by means of a realistic laparoscopic tool. CONCLUSIONS: Three-dimensional visualization of the organ in relation to the pathology is of great help to appreciate the complex anatomy of the liver. Using virtual reality concepts (navigation, interaction, and immersion), surgical planning, training, and teaching for this complex surgical procedure may be possible. The ability to practice a given gesture repeatedly will revolutionize surgical training, and the combination of surgical planning and simulation will improve the efficiency of intervention, leading to optimal care delivery.

[A diagnostic strategy in persistent hyperparathyroidism]. / Strategia diagnostica nell'iperparatiroidismo persistente.

BACKGROUND: Primary operations for hyperparathyroidism performed by experienced surgeons has a success rate of about 95% without any preoperative localization. After unsuccessful cervicotomy, localization studies must be performed in order to define the surgical approach. The objective of our retrospective studies was to determine the accuracy of non invasive and invasive localization studies in patients with persistent hyperparathyroidism. METHODS: The present reoperative series involved 7 patients with persistent hyperparathyroidism. Six patients came from a series of 140 operated on at the department of Prof. J. Marescaux from 1991 to 1993 (success rate of 95.7% in cervical exploration). Patient n. 7 came from another department. RESULTS: After negative initial cervicotomy, non invasive localization procedure are undertaken, but with a high incidence of false-positive results (9% to 75%). Among available invasive techniques, it has been chosen to sample blood from large veins in the neck and mediastinum for Parathyroid Hormone (1-84 PTH) determination and to realise angiography for locating parathyroid adenomas as well as for vein mapping. Their combination permitted to localize all lesions. CONCLUSIONS: The specificity of serum concentration of 1-84 PTH determination by catheterization of cervical and mediastinal veins (100%) combined to the sensitivity of angiography (82%) allowed to obtain good result in parathyroid localization in persistent hyperparathyroidism.

[A new concept in surgery of the digestive tract: surgical procedure assisted by computer, from virtual reality to telemanipulation]. / Un nouveau concept en chirurgie digestive: la procédure chirurgicale assistée par ordinateur, de la réalité virtuelle à la télémanipulation.

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.

[Duodenal lipoma causing intestinal subocclusion. Case report]. / Lipoma duodenale causa di subocclusione intestinale. Caso clinico.

Duodenum is a rare position for gastrointestinal lipoma which sometimes may lead to severe complications. Authors report the case of a 60-year old woman treated with a transduodenotomic excision through a midline laparotomy. At admission the patient presented epigastric pain for 1 month. Physical examination was negative except for a modest epigastric sensitivity. CT scan showed image with regular features and fat density, and permitted the exact preoperative diagnosis. Final histopathological examination confirmed the diagnosis.

Laparoscopic management of acute peritonitis.

BACKGROUND: The presence of peritonitis has previously been considered to be a contraindication for the laparoscopic approach because of the theoretical risk of malignant hypercapnia and toxic shock syndrome. The aim of this retrospective study was to demonstrate that laparoscopy is feasible, safe and efficient in cases of peritonitis. METHODS: From January 1990 to July 1995, 231 patients had a laparoscopy for acute peritonitis in two centres (91 appendicular peritonitis, 69 gastroduodenal perforated ulcers, 35 perforations of the colon, 36 miscellaneous). RESULTS: The diagnostic accuracy of laparoscopic exploration was 84.8 per cent. The clinical preoperative diagnosis was changed by laparoscopic exploration in 25.1 per cent of patients. An unnecessary laparotomy was avoided in 6.5 per cent of patients and the site of traditional incision was modified in 8.7 per cent. Conversion rates were 25 per cent for appendicular peritonitis, 16 per cent for gastroduodenal perforation and 83 per cent (29 of 35 patients) for colonic perforation. The overall mortality rate was 3.9 per cent. No malignant hypercapnia occurred. Two patients (0.9 per cent) had postoperative septic shock but survived. CONCLUSION: Laparoscopy is feasible and safe in cases of peritonitis. Laparoscopic treatment is particularly effective in the case of appendicular and gastroduodenal perforation. In the case of colonic perforation, the conversion rate remains high but with growing experience and surgical skill, more of these cases will be treated laparoscopically in the future.

[Perforated peptic ulcer and laparoscopic treatment]. / Ulcera peptica perforata e laparoscopia.

BACKGROUND: The purpose of this study is to evaluate the possibility, safety and advantages of laparoscopic approach in the diagnosis and therapy of perforated peptic ulcer. METHODS: This is a retrospective study including 69 cases of gastroduodenal perforation initially treated laparoscopically. The safety (morbidity and mortality) was estimated according to the two mortality rates fixed for laparotomies, APACHE II and Mannheimer Peritonitis Index (MPI). Sixty-nine patients (average age: 52 years), 23% of whom being over 70 years old, suffering from gastroduodenal perforation, were initially treated with laparoscopy. RESULTS: The laparoscopic diagnosis was done in 91% of cases. When the perforation was localized, the laparoscopic treatment was possible in 94% of cases. In 93% of cases a simple closure of the ulcerated perforation was performed. The conversion ratio was of 16%. One-hundred minutes (55-180) was the average operating. The morbidity was of 13%. One septic shock was reported in a patient with general purulent peritonitis diagnosed with laparoscopy and, after having converted, it was treated with laparotomy. No malignant iperCO2 was relieved. The reported mortality was of 4.3%, the theoretical mortality estimated was of 6% (MPI) and of 14% (Score APACHE II). The 3 deceased (87, 87 and 93 years old) had ASA index superior to 3. The remarkable advantage of laparoscopic approach is, in addition to diagnostic contribution, the absence of wall complications when the operation is not converted. CONCLUSIONS: The laparoscopic approach is suggested in gastroduodenal perforation, since it allows an etiological diagnosis and a treatment without conversion in 84% of cases.

In vivo laser-induced fluorescence imaging of a rat pancreatic cancer with pheophorbide-a.

Laser-induced fluorescence (LIF) of pheophorbide-a (Ph-a) was used for imaging of a rat pancreatic tumor. Using a dimensionless function (the ratio of Ph-a fluorescence by bluish autofluorescence), the fluorescence contrasts between excised tumors and their paired pancreas were investigated up to 48 h after a 9 mg kg-1 Ph-a intravenous administration. Among five tested excitation wavelengths, 355 and 610 nm excitations gave the best distinctive contrasts, both 48 h after dye injection. The LIF imaging of six intrapancreatic tumors and six healthy pancreas was carried out in vivo using two laser excitations: 355 nm (Nd:YAG + tripling) for bluish autofluorescence and 610 nm (rhodamine 6G dye) for reddish autofluorescence and dye emission. Images were recorded through bandpass filters at 470 and 640 nm (autofluorescence) and at 680 nm (dye + autofluorescence) with an intensified charged-coupled device camera. Autofluorescence as Ph-a fluorescence images did not allow accurate LIF diagnosis of pancreatic carcinoma. An image processing, including for each pixel a computed division of Ph-a fluorescence (after subtraction of reddish autofluorescence) by bluish autofluorescence intensity generated poorly contrasted tumor images in five of six and false tumor localization in one of three of the tumor-bearing pancreas. A fitting of the digital 640 nm autofluorescence up to the mean 680 nm fluorescence intensity in pancreas prior to subtraction allowed a safe diagnosis to be made with well-contrasted tumor images. To assess automation ability of the processing, a same fitting coefficient (mean of individual values) was applied. In this way, false-negative (one of six) and false-positive (two of six) images were present in tumor-bearing animals as false-positive in one-half of the controls. A successful standardized procedure was then applied with a normalization of 640 and 680 nm pancreas intensities to a same set threshold prior processing. In opposition to thin-layered hollow organs, such as bronchial tube or digestive tract, LIF imaging of carcinoma inserted in a compact organ is exhausting. The use of a dye excitable in the red wavelength range (610 nm for Ph-a) may partly solve this problem, rendering LIF imaging more accurate and potentially automated.

[Sequential treatment of lithiasis of the common bile duct]. / Il trattamento sequenziale della litiasi della via biliare principale.

The purpose of this study is to evaluate the sequential endoscopic-laparoscopic approach for clearance of common bile duct (CBD) and removal of gallbladder in patients with simultaneous cholecystolithiasis and choledocholithiasis. A data base of 990 patients undergoing Laparoscopic Cholecystectomy (LC) was compiled during an 5 years period. 88 patients were suspected of having CBD stones based upon clinical, biological and ultrasound evidence. The CBD cannulation rate was 93% (82/88). CBD stones were found in 43 patients (49%). The stones were removed preoperatively by Endoscopic Sphincterotomy (ES) in 37 patients of these 43 cases (86%). LC was performed in all patients after endoscopic retrograde cholangiopancreatography (ERCP). This treatment had showed no mortality and a morbidity of 14%. Efficacy of this sequential method of treatment of LVBP was 86%. With inclusion of laparoscopic extractions, the efficacy rate was 91%. The rate of residual stones was 1% (1/88). Experience with ERCP and ES before LC has been growing. ERCP-SE in the treatment of choice to clear the CBD before LC in high risk elderly patients (26) as well as in complicated stones. However, in this era of laparoscopic surgery, CBD stone can be removed laparoscopically in specialized centres with the advantage of a non-invasive single procedure for the patient. Laparoscopic CBD desobstruction and ES are not opposite but complementary. Preoperative ERCP and ES should be reserved for patients with serious illness. All other patients should be managed laparoscopically; in this case the future of sequential treatment resides in a one step-approach: preoperative ERCP if cholangiography is positive.

Influence of CO2 pneumoperitoneum on systemic and peritoneal cell-mediated immunity.

Port site metastases could be due to mechanical reasons or impairment of host defenses. As it is known that carbon dioxide is toxic for lymphocytes in vitro we decided to investigate lymphocyte stress during laparoscopy. Blood samples and peritoneal fluids were obtained before and after pneumoperitoneum from 16 patients undergoing laparoscopic cholecystectomy. Lymphocyte subsets were determined by flow cytometry. Propidium iodide was used as a lymphocyte vitality test. Cytokines were measured by an ELISA system. Significant falls in the absolute lymphocyte count and T3 and T4 lymphocytes occurred on postoperative day 1 with a quick return to the preoperative value on day 2. T8, natural killer cells, T4/T8, and T4+/T8+ counts were stable. Interleukins 1 beta and 6 and tumor necrosis factor-alpha were depressed during the two postoperative days. Peritoneal lymphocytes were not destroyed by pneumoperitoneum as demonstrated by the propidium test, nor were they locally impaired by carbon dioxide. The circulating lymphocyte subpopulation decrease favors moderate, brief immunodepression. The origin of port site metastases is not immunologic depression but, rather, facilitated implantation of malignant cells by hyperpressure into raw tissues.

[A new concept in digestive surgery: the computer assisted surgical procedure, from virtual reality to telemanipulation]. / Un nouveau concept en chirurgie digestive: la procédure chirurgicale assistée par ordinateur, de la réalité virtuelle à la télémanipulation.

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 reason 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 has to include five requirements: visual fidelity, interactivity, physical properties, physiological properties, sensory input and output. In this report we will describe how to get 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.

Laparoscopy not recommended for routine appendectomy in men: results of a prospective randomized study.

BACKGROUND: Laparoscopic appendectomy has now gained wider acceptance in clinical practice, particularly in the treatment of women with right iliac fossa pain. However, the precise role of laparoscopic appendectomy in men is unclear, and this study was therefore undertaken to examine this specific issue in a prospective randomized trial. METHODS: One hundred men between the ages of 16 and 65 years who had suspected appendicitis were recruited and randomized to undergo either open or laparoscopic appendectomy. Both groups were compared in terms of their clinical parameters, duration of anesthetic and operation times, postoperative pain, duration of ileus, and length of hospital stay. RESULTS: The histologic confirmation of appendicitis was present in 94% of the cases for both groups of patients. Laparoscopic appendectomy required significantly longer anesthetic time (72.5 minutes versus 55 minutes) and actual operating time (45 minutes versus 25 minutes) compared with open appendectomy. Postoperative pain as measured by visual analog scale on postoperative days 1 and 2 were not significantly different between the patients who underwent laparoscopic and open surgery with values of 4.7 versus 4.4 and 2.1 versus 2.2, respectively. Also no significant difference was seen between the laparoscopic and open appendectomy groups in the recovery of bowel function (24.7 hours versus 21 hours) and in the length of hospital stay (4.9 days versus 5.3 days). CONCLUSIONS: The results of this prospective randomized trial showed that there were no significant advantages of laparoscopic appendectomy over open appendectomy for the treatment of male patients with suspected appendicitis. We recommend that the use of laparoscopy be limited to men with atypical pain of uncertain diagnosis and in obese patients.

[Celioscopic digestive surgery: from the explosion to a critical reflexion]. / Chirurgia digestiva celioscopica: dall'esplosione alla riflessione critica.

A critical review of laparoscopic digestive surgery indications is proposed. Patient's benefit by laparoscopy is to undergo the same procedure as by open surgery with identical security conditions but with less postoperative pain and an earlier recovery. Today laparoscopy in digestive surgery is mainly indicated in the fields of functional and benign diseases. Oncology seems for our team to stay a relative contra-indication as yet. Taken into account the future technical progresses, this 1996 state of the art is obviously only a temporary view of the technique before expected mutations.

Photodynamic imaging of a rat pancreatic cancer with pheophorbide a.

Laser-induced fluorescence of pheophorbide a (Ph-a) was used for in vitro photodynamic imaging (PDI) of a rat pancreatic acinar tumor. A 400 nm excitation induced a 470 nm autofluorescence and a 678 nm dye fluorescence in tumors and their surrounding pancreas 24 h after a 9 mg kg-1 body weight Ph-a intravenous administration. With lower intensities in these blood-rich tumors than in pancreas, Ph-a fluorescence signals are unable to provide tumor images. A dimensionless function (the ratio of Ph-a fluorescence by autofluorescence, called Rt for the tumor and Rp for the pancreas) was used for fluorescence contrast calculation (C = Rt/Rp) between six tumors and their paired pancreas. Among five available laser excitation wave-lengths, only the 355 nm excitation gave a distinctive contrast (C = 1.5). The PDI of six intrapancreatic tumors and their intraperitoneal metastasis and of two control normal pancreas was thus performed ex vivo using a 355 nm excitation source delivered by a tripled Nd:YAG laser and a charged-coupled device camera. Fluorescence images were recorded at 680 nm (dye), 640 nm (background) and 470 nm (autofluorescence) through three corresponding 10 nm width bandpass filters. Computed division for each pixel of Ph-a fluorescence values by autofluorescence generated false color image. In this way, contrasted tumor images were obtained. But in five out of six animals false-positive images were present due to an autofluorescence decrease in some normal pancreatic areas. A 470 nm autofluorescence imaging on the same tumors gave in all cases false-positive image and false-negative in half of the cases. These observations suggest that autofluorescence alone is unable to achieve accurate PDI of pancreatic carcinoma and that using Ph-a as a PDI dye needs strong improvements.

Geometric and physical representations for a simulator of hepatic surgery.

Despite the large interest in simulators of minimally invasive surgery, it is still unclear to what extent simulators can achieve the task of training medical students in surgical procedures. The answer to that question is certainly linked to the realism of displays and force-feedback systems and to the level of interaction provided by the computer system. In this paper, we describe the virtual environment for anatomical and surgical training on the liver, currently under construction at INRIA. We specifically address the problems of geometric representation and physical modeling and their impact on the two aforementioned problems: realism and real-time interaction.