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J Marescaux

Publications and source records attributed to J Marescaux.

At least 55 records · Page 3Linked to original sources
PubMed1998

Role of nitric oxide in pancreatic tumour growth: in vivo and in vitro studies.

Nitric oxide (NO), an endogenous free radical, has been implicated in a wide range of biological functions. NO is generated enzymatically from the terminal guanidinonitrogen of L-arginine by nitric oxide synthase (NOS). Despite intensive investigations, the role of NO--either as the primary product of the L-arginine/NOS pathway or provided from the NO donor sodium nitroprusside (SNP)--in carcinogenesis and tumour cell growth remains unclear and controversial. The objective of this study was to examine the growth effects of NO on a ductal pancreatic adenocarcinoma in the rat and on a human pancreatic tumour cell line (HA-hpc2). In vivo, both SNP and endogenous induction of NO by endotoxins [lipopolysaccharide (LPS)] plus L-arginine significantly reduced the tumour growth. To investigate the mechanisms of NO anti-tumour growth action, the effects of either the SNP or L-arginine/NOS pathway were analysed on the HA-hpc2 cell line. Nitrite/nitrate production, NOS activity and iNOS expression [assessed by reverse transcription-polymerase chain reaction (RT-PCR)] were tested and related to growth (assessed by [3H]thymidine incorporation assay) and apoptosis (assessed by internucleosomal DNA cleavage). SNP exerted a dual effect on tumour cells: stimulation of the proliferation up to 1 mM and inhibition at higher concentrations. These effects were related to NO production. Both proliferative and cytostatic responses were inhibited by NO scavenger 2-phenyl-4,4,5,5-tetramethyl-hemidazoline-1-oxyl3-oxide (carboxy-PTIO). The marked apoptotic DNA fragmentation induced by SNP was also abolished by PTIO association. Unlike macrophages, the human pancreatic tumour cells did not seem to express intrinsically the L-arginine/NOS pathway. Macrophages were activated by HA-hpc2 cells as well as by LPS plus cytokines [interleukin (IL)-1beta plus tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma]. In HA-hpc2/macrophage co-cultures, NOS activity and inducible NOS (iNOS) transcription were stimulated, whereas an antiproliferative response was observed. These effects were related to both macrophage amount and NO production. Addition of LPS plus cytokines to co-cultures doubled iNOS activity, nitrite/nitrate production and tumoricidal effect. These data suggest the involvement of NO in pancreatic tumour growth and support the fact that generation of high levels of NO with potential production of endogenous reactive nitrogen intermediates may contribute to induction of apoptosis and tumour growth inhibition.

Animals↗
PubMed1998

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.

Acute Disease↗
PubMed1998

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.

Computer Simulation↗
PubMed1998

[A diagnostic strategy in persistent hyperparathyroidism].

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.

Adult↗
PubMed1998

[Video laparoscopic adrenalectomy].

BACKGROUND: The authors describe the surgical technique for right and left adrenalectomy and the per- and postoperative course of the patients. METHODS: Twenty-seven laparoscopic adrenalectomies were performed between November 1992 and February 1996: there were 18 women and 9 men ranging in age from 31 to 70 years (mean 50.8 years); the surgical procedure was a lateral decubitus transperitoneal flank approach in 26 patients, and a retroperitoneal approach in one. RESULTS: Twelve right and 15 left glands were removed. Adrenal diseases were primary aldosteronism in 20 patients, non-functional adenoma in 3 patients, 2 Cushing's syndrome, adrenal cyst in one and incidentaloma in one. Mean adrenal gland size was 2.6 cm (range 0.5 to 8 cm). Five patients (18.5%), were converted to laparotomy, for dissection problems in 4 and failure to locate the left adrenal gland in one. The mean anesthesia time was 205.7 min and the mean surgical time 141.2 min. Surgical morbidity was one adrenal vein injury sectioned close to the vena cava: the hemorrhage was controlled by laparoscopic suturing without conversion. No mortality occurred and postoperative morbidity was one minor chest infection. The mean postoperative stay in hospital was 3.7 days (range 2.8) for the non converted patients. Laparoscopic adrenal gland removal is safe and offers fast recovery and short hospital stay. Laparoscopic adrenalectomy combines the advantages of both the conventional anterior and posterior approach. CONCLUSIONS: Personal experience of laparoscopic adrenal gland removal is described: a safe adrenal vascular control and gland dissection were performed and the length of operation and postoperative course carefully presented.

Adrenalectomy↗
PubMed1998

[Perforated peptic ulcer and laparoscopic treatment].

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.

Aged↗
PubMed1997

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.

Carbon Monoxide↗
PubMed1997

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.

Animals↗
PubMed1997

Interstitial laser photocoagulation of osteoid osteomas with use of CT guidance.

PURPOSE: To evaluate interstitial laser photocoagulation (a minimally invasive percutaneous technique of thermal destruction of deep-seated tumors, with low-power laser energy) in local destruction of osteoid osteoma, with computed tomographic (CT) guidance. MATERIALS AND METHODS: Fifteen patients (age range, 8-48 years) with presumed osteoid osteoma were treated with CT-guided interstitial laser photocoagulation of the nidus. A high-power semiconductor diode laser (805 nm) with a 400-microm optical fiber was used. The fiber was introduced into the nidus through an 18-gauge needle. Around the fiber tip, well-defined coagulative necroses from 5 to 9 mm (energy delivery, 400-1,000 J) were obtained. RESULTS: Fourteen patients had complete pain relief, which was apparent within 24 hours in eight patients. One patient had recurrence of pain after 6 weeks. The remaining nidus was treated a second time, with complete relief. Treatment was unsuccessful in one patient, and surgical excision was performed. Daily activities were not restricted after the intervention. All patients were followed up for more than 1 year, with no sign of recurrence. The only notable complication was a mild reflex sympathetic dystrophy of the wrist in one patient. Sclerosis of the nidus was observed 4-6 months after the procedure. CONCLUSION: Percutaneous interstitial laser photocoagulation of osteoid osteoma seems to be a promising, simple, precise, and minimally invasive alternative to traditional surgical and percutaneous ablations.

Activities of Daily Living↗
PubMed1997

Evaluation of human collagen biomaterials in the healing of colonic anastomoses in dogs.

OBJECTIVE: To investigate the ability of human collagen biomaterials to secure colonic anastomoses in dogs and to evaluate the biocompatibility of anastomotic protection patches (APP). DESIGN: Experimental open study. SETTING: Experimental research centre, France. MATERIAL: 21 mongrel dogs randomised into three groups of 7 each. INTERVENTION: Standard transverse colonic end-to-end anastomoses were secured with two-layer oxidised collagen I + III sponge covered with thin crosslinked collagen IV film (APP 1) glued around the suture (n = 7); two-layer oxidised collagen I + III sponge covered with thin non-crosslinked collagen I + III film patch (APP 2) (n = 7); or sealed by fibrin sealant (n = 7), which acted as a controls. MAIN OUTCOME MEASURES: Gross examination, radiological control (barium enemas), and microscopic examination on day 35 postoperatively. RESULTS: Gross clinical and radiological examinations on day 35 showed normal wound healing in all but one dog in which the anastomoses had occluded by day 16. There was significantly less stricturing with the APP 2 patch (p < 0.05 compared with the controls). Microscopic examination showed complete absorption of the APP 2 patches as well as quicker mucosal and extracellular matrix repair than controls. The APP 1 patch gave the best healing of the muscular layer but did not reduce anastomosis stricturing, and was not totally absorbed. CONCLUSIONS: Collagen supporting devices do not alter healing of the large bowel. Encircling patches do not increase the number of adhesions or the rate of anastomotic stricturing and a thin fibrillar collagen I + III dense layer may even improve it. The speed of absorption of the patch depends on the type of dense collagen film. These results argue for a prospective clinical evaluation in humans.

Analysis of Variance↗
PubMed1997

[Nonrecurrent recurrent nerve. Danger in thyroid and parathyroid surgery. Apropos of 9 cases].

Main difficulties in thyroid surgery are represented by recurrent nerve anatomy and parathyroid glands. Nerve injury or accidental truncation cause definitive impairment. Risk of recurrent paralysis is 0.5 to 3% for advanced teams. Early investigation and dissection of this nerve are considered mandatory for preservation. This practice is also highly indicated due to anatomical variations, cause for accidental truncation. The most difficult case is encountered when there is nerve non recurrence, due to variations in origin and path of the nerve. Inferior laryngeal nerve non recurrence can be present on the right side, it is uncommon but possible on the left side. We have evaluated a series of 1165 cervicotomies undertaken for thyroidectomy or parathyroid gland approach. There were 9 cases of non recurrence. Literature review allowed us to study anatomical variations and nerve relationships.

Humans↗
PubMed1997

[Thyroid and parathyroid surgery: is the medial approach truly elective? Technique and advantage of the lateral approach].

The authors describe the lateral approach technique in thyroid and parathyroid surgery which they consider the elective one. They also illustrate the advantages in dissection of laryngeal nerves and parathyroids, as well in difficult situations. They used it from 1984 to 1994 systematically in 1165 patients, 764 operated for thyroid pathology and 401 for parathyroid. No damage linked to the technique was observed.

Humans↗
PubMed1997

[A new concept in digestive surgery: the computer assisted surgical procedure, 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 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.

Computer Simulation↗
PubMed1997

[Telesurgery: standards--consultations--continuing education].

The aim of the TESUS project is to bring together several European university hospitals in a federation as well as a certain number of clinical centers in a network, the purpose of which is the online and offline transmission of surgical procedure imaging and advice. The innovation is threefold: It provides the surgeon with online information, diagnostic and therapeutic tools and expert advice, the need for which might come up before and during surgical procedures, as well as the same services in the context of teaching and training through regular staff. The developed services will be a major contribution to EU-wide standardisation of health care procedures and therapeutic approaches.

Computer Communication Networks↗
PubMed1996

Laparoscopic right and left adrenalectomies. Surgical procedures.

BACKGROUND: Laparoscopic approach for adrenalectomy was recently described and the operative technique is not yet well defined. METHODS: Twenty-seven laparoscopic adrenalectomies were performed between 1992 and 1995. There were 18 women and nine men ranging in age from 31 to 70 years (mean, 50.8 years). The surgical procedure was a lateral decubitus transperitoneal flank approach in 26 patients, and a retroperitoneal approach in one. Twelve right and 15 left glands were removed. Adrenal diseases were primary aldosteronism in 20 patients, nonfunctional adenoma in four patients, Cushing adenoma in two, and an adrenal cyst in one. Median adrenal gland size was 2.0 cm (range 0.5-8 cm). RESULTS: Five patients were converted to laparotomy (18%)-for dissection problems in four and for an unrecognized gland in one. The median anesthesia time was 200 min and the median surgical time was 140 min. Operative morbidity was one adrenal vein injury sectioned close to the vena cava. The hemorrhage was controlled by laparoscopic suturing without conversion. This patient required a three-unit blood transfusion. No mortality occurred and postoperative morbidity was one minor chest infection. The median postoperative in-hospital stay was 4.6 days (range 2-8) for nonconverted patients. CONCLUSIONS: Laparoscopic adrenal gland removal is safe and offers fast recovery and short in-hospital stay. Laparoscopic adrenalectomy combines the advantages of both the conventional anterior and posterior approach.

Adenoma↗
PubMed1996

Biomaterial supports for colonic wall defect healing. An experimental study in the rat.

New artificial biomaterials were tested for support of gastro-intestinal tract wound healing in the rat. Double layered collagenic matrices were prepared with purified collagens extracted from human placental tissues. Two types of patches were tested, the first constituted from a collagen type I + III layer covered by collagen IV in a liquid phase (patch I + III/IV) and the second from a collagen IV layer covered by liquid collagen IV (patch IV/IV). The matrices were applied with fibrin sealant to the edges of a 1 cm diameter colonic wall defect in the rat. Healing evolution was determined by macroscopic, microscopic and immunostaining studies. The reconstitution of the three colonic wall layers was achieved within 45 days without retraction or inflammatory reaction, while the biomaterial was resorbed. Human collagen I and III antibodies failed to stain extracellular matrix. This failure may be a consequence of outdated antibodies or more likely epitope alteration during extraction and preparation of the collagens. A human collagen type IV antibody staining of the scar zone showed the basement membranes of newly developed vessels within 10 days, and newly formed colonic mucosa within 20 days. The collagen reconstituted matrix was able to assist healing of normal digestive tract defects as shown by the labelling of the new synthesized extracellular matrix by collagen type IV antibody. These findings support the use of collagen biomaterial in gastro-intestinal anastomosis. This new surgical approach allowing healing of colonic wall defects could reduce occurrence of anastomotic leakage in human.

Animals↗