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Biomedical subjects

Y M Dion

Publications and source records attributed to Y M Dion.

At least 19 recordsLinked to original sources
PubMed1999

Laparoscopic end-to-end aortobifemoral bypass with reimplantation of the inferior mesenteric artery. An experimental study.

BACKGROUND: Colic ischemia is a serious complication that can occur after abdominal aortic surgery. It has been described in two patients after laparoscopic aortic surgery. The goal of the current experiment was to determine the feasibility of inferior mesenteric artery (IMA) reimplantation during laparoscopic aortobifemoral bypass (LAFB). METHODS: Six piglets were submitted to the laparoscopic approach according to the "apron" technique previously described. The infrarenal aorta was clamped and an LAFB was performed using a dacron graft. The IMA was reimplanted in the body of the graft with a running 5-0 polypropylene suture. RESULTS: Mean operation and dissection times were 282.5 min (range, 270-310 min) and 123 min (range, 110-140 min), respectively, with a mean blood loss of 108 ml (range, 80-150 ml). Aortic clamping and anastomotic times were 123 min (range, 110-135 min) and 33 min (range, 24-45 min), respectively. The IMA reimplantation took 55 min (range, 45-70 min). At autopsy, all anastomoses were patent with no stenosis nor leak. CONCLUSION: Laparoscopic IMA reimplantation during laparoscopic aortobifemoral bypass is feasible.

Anastomosis, Surgical↗
PubMed1999

Experimental laparoscopic aortobifemoral bypass with end-to-side aortic anastomosis.

The goal of this animal experiment was to demonstrate the feasibility of laparoscopic end-to-side aortic anastomosis, which is mandatory in certain cases presenting with aortoiliac occlusive disease. Six piglets were submitted to laparoscopic approach of the aortoiliac vessels using the "apron" technique. After clamping the infrarenal aorta with a laparoscopic Satinsky clamp, a 3-cm end-to-side laparoscopic aortic anastomosis was constructed. Mean operative and dissection times were 198 (170-240) and 92 (75-105) min, respectively, with a mean blood loss of 86 (50-120) mL. Mean preoperative and postoperative hematocrits were 38 (3448) and 38 (34-46). Aortic cross-clamp and anastomotic times were 51 (40-65) and 44 (35-60) min, respectively. No extra sutures were needed to secure the anastomoses. At autopsy, all the anastomoses were patent without stenoses. Results indicate the feasibility of laparoscopic aortobifemoral bypass with an end-to-side aortic anastomosis.

Anastomosis, Surgical↗
PubMed1998

Totally laparoscopic aortobifemoral bypass: a review of 10 patients.

The main purpose of this study is to evaluate the feasibility of totally laparoscopic aortobifemoral bypass for occlusive aortoiliac disease. Ten patients who had incapacitating claudication have been included to date in this investigation. We have designed a transabdominal retroperitoneal technique that allows performance of the procedure without the problems associated with retraction of intraperitoneal organs. During the study, surgery time decreased from 510 to 245 min. Mean total aortic clamping time was 121 min, and the mean time required to perform the aortic anastomosis was 66 min. Mean blood loss was 820 ml. Three patients needed conversion. Postoperative complications developed in three patients. One had an aortoureteral fistula, which needed reoperation; one experienced complications related to a retroaortic left renal vein; and the third had a mild compartment syndrome of the right leg. Totally laparoscopic aortobifemoral bypass is feasible. Laparoscopic aortobifemoral bypass appears to ease the patient's postoperative course and could become in the not so distant future part of the repertoire of the surgeon performing vascular surgery.

Adult↗
PubMed1997

Visual integration of data and basic motor skills under laparoscopy. Influence of 2-D and 3-D video-camera systems.

BACKGROUND: The qualities of visual perception and of motor reaction to the visual stimulus have never been studied in reference to the type of video-camera system (2-D vs 3-D) used during laparoscopy. METHODS: The study was designed in two parts. The first evaluated the ability of the eye to discriminate how objects are spaced relative to one another. The second investigated the motor reaction to the visual stimulus in an environment where depth was the preponderent cue. The tests were performed in a pelvi-trainer in which were inserted different modules built either for visual observation (Part 1) or for evaluation of motor ability (Part 2). Variables studied during Part 1 were the time required to do the test and the number of errors committed during its performance. The variable evaluated during Part 2 was the time needed to terminate the test. Each of these two parts of the study were completed alternating the 2-D and 3-D systems. A total of 304 observations were recorded. Statistics used were the paired t-test, the independent group t-test, and the Newman-Keuls multiple comparisons test. RESULTS: Results of Part 1 of the study confirm that visual perception varies significantly among individuals (n = 10) (p < 0.05) and that a true 3-D video-camera system facilitates visual perception when compared to a 2-D system (p < 0.001). Results of Part 2 of the study also show significant differences among participants (n = 9)(p < 0.05). The true 3-D system allowed significantly faster motor performances than the 2-D system (p < 0.001). CONCLUSION: Our experiment shows that the 3-D system allowed significant improvements in the execution of the evaluated parameters. Also noted were significant differences among participants in term of visual and motor skills.

Humans↗
PubMed1997

A new technique for laparoscopic aortobifemoral grafting in occlusive aortoiliac disease.

PURPOSE: This article describes an original laparoscopic technique that allows performance of aortobifemoral bypass grafting. METHODS: The technique described is the result of 6 years of in vitro and animal experimentation. It also represents the end result of prior clinical research with laparoscopy-assisted aortoiliac surgery and totally laparoscopic retroperitoneal aortobifemoral bypass grafting. The technique consists of the creation of a flap of retroperitoneum that is used to separate the intraperitoneal organs from the content of the retroperitoneal cavity. Surgery can then be conducted with no intrusion of any intraabdominal organ into the operative field. Another advantage is that the pneumoperitoneum is equally distributed among the two cavities. A conventional aortobifemoral bypass procedure is then performed with laparoscopic instrumentation. RESULTS: The described technique has been performed in three patients to date. The patients' intraoperative blood loss did not exceed 500 ml, and no complication arose. The intraoperative need for crystalloids was of the order of 3 L (almost half the quantity usually administered). The patients' analgesia requirement was low in these patients, and return to walking was rapid. They were sent home between the fourth and sixth postoperative days. CONCLUSIONS: The innovative technique described here is safe and appears to ease the patient's postoperative course. Data recovered from the multicenter study, which is now in its preliminary phase, should help answer numerous questions. We expect the procedure to be reproducible in other university centers that are participating in the trial.

Aorta, Abdominal↗
PubMed1996

Laparoscopic inguinal herniorrhaphy: appraisal of a cohort study.

OBJECTIVES: To assess the safety and effectiveness of individualized laparoscopic herniorrhaphy and to compare its intraoperative cost to that of the standard Bassini operation. DESIGN: An analytic cohort study. SETTING: A university teaching hospital. PATIENTS: One group of 158 patients underwent 167 laparoscopic herniorrhaphies for symptomatic groin hernias. The approach was transabdominal preperitoneal for the first 124 patients and totally preperitoneal for the last 34 patients. A second group of 50 patients underwent a conventional Bassini operation. INTERVENTION: Individualized laparoscopic inguinal herniorrhaphy or Bassini herniorrhaphy. MAIN OUTCOME MEASURES: Complications and recurrences encountered in the laparoscopic group. Total operative time and intraoperative cost involved in both procedures. Analgesia required in each group during the first 2 postoperative days. RESULTS: Intra- and postoperative complications of the laparoscopic approach were not life threatening. The recurrence rate at a mean follow-up of 16.8 months was 1.2%. Total operative time was significantly (p < 0.001) longer in the laparoscopy group than in the Bassini group. Patients in the Bassini group took more parenteral analgesics than those in the laparoscopy group (p = 0.02), but there was no difference with respect to the number of times enteral analgesics were required (p = 0.32). Use of mesh and staples was more expensive than sutures alone inserted laparoscopically. The Bassini procedure was a less expensive procedure than laparoscopic herniorrhaphy. CONCLUSIONS: The laparoscopic treatment of groin hernias is safe. The recurrence rate is low. Primary unilateral inguinal hernias could be adequately treated at a lesser cost by a standard approach. Bilateral, recurrent and femoral hernias could benefit from a laparoscopic approach.

Adult↗
PubMed1996

Experimental laparoscopic aortic aneurysm resection and aortobifemoral bypass.

The purpose of the present study was to develop a technique for laparoscopic aortic aneurysm resection and aortobifemoral bypass through an anterior retroperitoneal approach. Eight piglets weighing between 75 and 80 kg were anesthetized. The concepts of Shumacker's anterior retroperitoneal exposure of the aorta were modified to allow laparoscopic exposure of the aorta in the first four animals. The other four animals were treated as if they had an aortic aneurysm. The piglet is placed in a supine position. The first port (1.5 cm) is placed laterally near the tip of the 12th rib. As much dissection of the retroperitoneum as possible is performed digitally through this port. A second port (1.5 cm), through which an abdominal lift device and a peritoneal retractor will be inserted, is created superiorly just lateral to the left rectus sheath, and a plane is developed that joins the original dissected space. Two other ports (1.5 cm) are placed in the flanks in a plane inferosuperior to the first port. The surgeon will use two of the lateral ports, and the third one is for the laparoscope. The last two ports (1.5 cm), from which the assistant will work, are placed in the left paramedian region. Using this approach, we performed four aortobifemoral bypasses in an average of 4.5 h after conventional i.v. heparinization (100 IU/kg) with minimal bleeding (blood loss < 550 cc). After infrarenal aortic cross-clamping, the external iliac and caudal vessels were either tied with 0-chromic or occluded with laparoscopic bull-dogs. The aorta was opened, and bleeding lumbar arteries and the aortoiliac junction were sutured with 4-0 Prolene. The vascular graft was sutured end-to-end to the aortic stump with running 4-0 Prolene. Tunneling to the femoral regions was made easy by the position of the animal. No mortality occurred before sacrifice of the animals. This laparoscopic animal model paves the way for human aortic aneurysm replacement.

Animals↗
PubMed1996

Experimental laparoscopic aortobifemoral bypass for occlusive aortoiliac disease.

OBJECTIVE: To describe a totally laparoscopic technique for aortobifemoral bypass to treat aortoiliac atheromatous occlusive disease. DESIGN: A feasibility study. SETTING: A university teaching hospital. SUBJECTS: Six piglets weighing between 70 and 80 kg were submitted to a totally laparoscopic retroperitoneal aortobifemoral bypass, performed through six trocar sites, with abdominal suspension and a gasless technique. No minilaparotomy was performed. After systemic heparinization, the infrarenal aorta was cross-clamped and the aortic bifurcation stapled. An end-to-end aorto-prosthetic anastomosis was performed. Retroperitoneal tunnels were created to allow each limb of the graft to join its corresponding femoral artery by a conventional anastomosis. INTERVENTION: Totally laparoscopic aortobifemoral bypass. MAIN OUTCOME MEASURES: Duration of the procedure, intraoperative blood loss and operative complications, bleeding in the immediate postoperative period. Evaluation of the aortic anastomosis at autopsy. RESULTS: All aortobifemoral bypasses were completed in less than 4 hours. Intraoperative blood loss did not exceed 250 mL. No intraoperative complication was encountered except occasional bleeding at the aortic anastomosis upon releasing the arterial clamp. This was controlled with a collagen sponge (three cases) or extra stitches (two cases). The animals were observed for 15 minutes before sacrifice. Autopsy revealed a normal aortic anastomosis in all cases and a normal progression of the limbs of the graft under the ureters in the retroperitoneal tunnels. CONCLUSIONS: This animal model demonstrates the feasibility of the aortobifemoral bypass through a laparoscopic approach. The retroperitoneal anatomy of the piglet is similar to that of man. Aortic surgery can be conducted as for the standard technique. We used a similar approach to perform the first human, totally laparoscopic aortobifemoral bypass with an end-to-end anastomosis.

Anastomosis, Surgical↗
PubMed1995

Experimental carbon dioxide pulmonary embolization after vena cava laceration under pneumoperitoneum.

The potential for pulmonary embolization following major venous laceration occurring during laparoscopic surgery has never been evaluated. Five anesthetized dogs were hemodynamically monitored with an arterial line and Swan-Ganz catheter. Observation by transesophageal echocardiography (TEE) allowed comparison with pulmonary artery pressure (PAP) recording. Under pneumoperitoneum, a 1-cm venotomy was performed in the infrarenal vena cava and a total of 11 events were evaluated upon unclamping the venotomy. These results were compared with intravenous (i.v.) bolus injections of 15 cc of CO2 (15 events) and of 100 cc of CO2 (12 events). The animals were maintained euvolemic. In 2 out of the 11 (18%) events which followed unclamping the venotomies, a few CO2 bubbles were seen in the right heart cavities. However, the quantity of gas was much less important than that seen after i.v. injection of 15 cc and 100 cc of CO2. There was no significant elevation of the PAP from pre-event values after venotomy or after i.v. injection of 15 cc of CO2. However, there was a significant difference (P < 0.05) when these results were compared to the PAP values recorded after i.v. injection of 100 cc of CO2. No dog died after these episodes of embolization. Massive i.v. injection of CO2 (> 300 cc) led to appearance of gas bubbles in the left heart cavities and death. This experiment suggests that caution should be exerted when laparoscopic surgery is performed beside large veins. Nevertheless, the observation that no gas embolism occurred in 82% of the cases after unclamping venotomies was unexpected. In contrast, many more gas bubbles were detected in the right heart after i.v. injection of only 15 cc of CO2. TEE is a more sensitive indicator of pulmonary embolization than elevation of PAP.

Animals↗
PubMed1995

Experimental laparoscopic aortobifemoral bypass.

The goal of the present study is to develop a technique for laparoscopic aortobifemoral bypass. Piglets weighing between 60 and 78 kg were anesthetized with halothane. The lateral retroperitoneal approach was preferred to the more familiar anterior transperitoneal approach and was successfully completed in 19 piglets. The piglets were placed in the right lateral decubitus position. The first port (2 cm) was inserted halfway between the tip of the 12th rib and the iliac crest. Four other trocars were placed in the retroperitoneum after balloon inflation had allowed creation of a space which permitted visualization of the aorta from the left renal artery down to the aorto-iliac junction. After evacuation of the retropneumoperitoneum, the cavity was maintained using an abdominal lift device and a retractor. Using this approach, we performed four aorto-bifemoral bypasses (end-to-end aortic anastomosis) after conventional intravenous heparinization (100 IU/kg) in less than 4 h. Blood loss did not exceed 250 ml and the hematocrit remained stable. Postmortem evaluation of the grafts revealed they were positioned as in a conventional bypass, their limbs having followed in the created retroperitoneal tunnels along the path of the native arteries. No mortality occurred before sacrifice of the animals. We believe that this first performed series of totally retroperitoneal laparoscopic aortobifemoral bypasses in the porcine model is useful in preparation for human application due to the anatomical similarities in the periaortic region.

Anastomosis, Surgical↗
PubMed1995

The role of extracorporeal shock-wave lithotripsy in the treatment of symptomatic cholelithiasis.

OBJECTIVES: To determine the effectiveness of extracorporeal shock-wave lithotripsy (ESWL) and adjuvant bile-salt therapy for the treatment of symptomatic cholelithiasis. DESIGN: A prospective case study. Follow-up ranged from 3 to 54 months. SETTING: A university teaching hospital. PATIENTS: Two hundred and twenty-three patients with symptomatic cholelithiasis, a gallbladder that opacified at oral cholecystography and three or fewer radiolucent stones with a maximum total dimension of 3 cm. Of these patients, 197 were given bile salts (ursodeoxycholic acid or chenodeoxycholic acid, 8 to 10 mg/kg daily) and underwent ESWL. Twenty-eight were excluded because of noncompliance with the protocol or treatment failure before termination of the ESWL procedure. INTERVENTION: ESWL with a piezoelectric lithotripter. MAIN OUTCOME MEASURES: The success rate of the intervention, the causes of failure, associated complications and the recurrence rate of cholelithiasis. RESULTS: Of the 197 patients who underwent ESWL, 85 (43%) were free of stones after treatment. Treatment failure was caused by the following: unsatisfactory fragmentation (9%), increase in fragment size during bile-salt therapy (8%), severe diarrhea due to bile salts (3%), nonvisualization of fragments after the first ESWL (3%), acute cholecystitis (2%), persistence of small fragments at the end of the treatment protocol (2%) and acute pancreatitis (0.5%). Complications included biliary colic (21%), diarrhea (15%), acute cholecystitis (2.5%), acute pancreatitis (2%), macroscopic hematuria (2%), perirenal hematoma (0.5%) and vagal shock (0.5%). The recurrence rate was 18%. Causes of noncompliance with treatment (26%) were the length of treatment, the occurrence of biliary colic during this period and the high cost of bile salts. CONCLUSION: ESWL with bile salts as treatment for symptomatic cholelithiasis is not recommended for routine use.

Adult↗
PubMed1994

The influence of the number of endoclips and of mesh incorporation on the strength of an experimental hernia patch repair.

The strength conferred to a mesh by fixing it with laparoscopic staples and the effects of tissue incorporation have never been quantified. Eighteen dogs were divided into three groups sacrificed at 2 days (5 dogs), 2 weeks (6 dogs), and 2 months (7 dogs). One 3.5- by 5-cm piece of abdominal wall was removed from each side through a median laparotomy, leaving the skin intact. A polypropylene mesh (5 by 7 cm) was fixed over one defect with four Endopath EMS staples (Ethicon Endo-surgery) and over the other with 16 EMS staples. At sacrifice, bursting strength (BS) was measured with an Instron tester and specimens were studied histologically. One-way analysis of variance and the Newmann-Keuls multiple-comparison test were used. BS tests showed that for each period studied, the strength of the repair performed with 16 staples was significantly higher than that obtained when four staples were applied. They also showed that tensile strength increased significantly in both groups as time elapsed. Light microscopy supported the conclusion that the initial strength of the repair was related to the number of clips and was significantly increased by cellular infiltration at 2 weeks and significantly more by collagen deposition at 2 months. At 2 months, BS was significantly higher in the 16-staples group, suggesting that initial fixation still plays a significant role.

Abdominal Muscles↗
PubMed1994

Bursting strength evaluation. Comparison of 0-Prolene sutures and endoscopic staples in an experimental prosthetic patch repair of abdominal wall defect.

Recently, titanium staples have been designed to stabilize a small prosthetic mesh used for laparoscopic herniorrhaphy. Unlike the giant prosthesis employed by Stoppa, the small mesh must be fixed to the surrounding musculo-aponeurotic defect. The strength of these titanium staples has never been evaluated and was compared to 0-Prolene sutures. In an ex vivo study, we evaluated the maximal stress (bursting strength [BS]) a repair performed with 0-Prolene sutures or staples can bear. Bilateral abdominal-wall defects were created in 16 piglets. A Prolene mesh was fixed preperitoneally on one side of the abdomen with 0-Prolene sutures and on the other side with the Endopath EMS stapler or the Endo Hernia stapler. The mean BS of meshes attached with 0-Prolene was 1,461.7 mmHg. The mean BS of meshes fixed with Endopath EMS staples was 885.5 mmHg and that of meshes fixed with Endo Hernia staples was 665.2 mmHg. A repair with 0-Prolene sutures is stronger (P < 0.05) than one with staples (Endopath EMS or Endo Hernia). Also, repair with an Endopath EMS stapler has a significantly higher BS (P < 0.05) than one with the Endo Hernia stapler. In the second part of the study, evaluation of the longitudinal tensile strength also showed that 0-Prolene sutures are stronger (P < 0.05) than staples. Endopath EMS staples are stronger (P < 0.05) than Endo Hernia staples.

Abdominal Muscles↗
PubMed1994

Mechanical characterization of endoscopic surgical staples during an experimental hernia repair.

Recent developments in laparoscopic hernia repair techniques have led to the design of titanium staples. In a laparoscopic hernia repair, a polypropylene mesh is stapled over the direct and indirect hernia sites in the inguinal region. The effectiveness of these staples in holding the prosthetic mesh, and therefore providing adequate strength to the abdominal wall, has not been yet investigated. We have characterized the bursting strength (BS) of an experimental hernia mesh repair fixed with Prolene suture, which is used extensively for this procedure, and the BS of repairs fixed with two currently available staplers, the Endopath EMS endoscopic multifeed stapler and the Endo Hernia stapler. We first simulated abdominal wall hernias in 16 piglets by creating incisions on both sides of the abdomen of each animal. Each defect was then covered with a polypropylene mesh, which was fixed on one side with Prolene sutures and on the other side using either the Endopath EMS (Group 1) or the Endo Hernia stapler (Group 2). The abdominal tissue with the mesh covering the defect was then excised and the BS evaluated using an Instron machine. Since many mechanical characteristics contribute to the BS of a repair, we investigated these characteristics in vitro, including tensile properties of the staples and the prosthetic mesh as well as the suture-tearing resistance of the mesh. Polypropylene mesh exhibits the same elongation in the three directions, i.e. 0 degrees , 45 degrees and 90 degrees . This elongation was estimated at 136% (SD = 130).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Common bile duct exploration: the place of laparoscopic choledochotomy.

Since laparoscopic cholecystectomy was introduced, the treatment of choledocholithiasis has been modified. Preoperative endoscopic retrograde cholangiopancreatography (ERCP) has been performed selectively in elderly patients and in those with a strong suspicion of biliary duct stones (jaundice, demonstrated at ultrasound). Intraoperative discovery of common duct stones at cystic duct cholangiography signifies that they must be removed intraoperatively [or postoperatively by ERPC and endoscopic sphincterotomy (ES)]. As ES has a failure rate of 3-23%, laparoscopic common duct exploration emerges as the treatment of choice. Since November 1990, we have performed 59 laparoscopic common bile duct explorations. In our experience, the transcystic technique (18 patients) with choledochoscopy appears easier to perform than with fluoroscopy without choledochoscopy. Since, during our early experience, we encountered some difficulty with the transcystic technique, we elected to evaluate common duct exploration through a choledochotomy (41 patients). The main advantage of this technique is that it provides complete access to the ductal system without damage to the papilla. This procedure seems more difficult to perform than the transcystic technique and can be used when there are contraindications to the latter.

Adult↗
PubMed1993

Laparoscopy-assisted aortobifemoral bypass.

Therapeutic laparoscopy has substantially simplified the postoperative course of patients suffering from hepatobiliary, gastric, or colonic disease. One important advantage of this modality is the decrease in postoperative pain, which diminishes the potential for cardiopulmonary problems. Patients with aortoiliac atherosclerotic disease are at high risk for postoperative complications, and a minimally invasive procedure may favorably affect their postoperative recovery. We describe here the first patient on whom we performed a laparoscopy-assisted aortobifemoral bypass. Under the pneumoperitoneum, seven 10-mm trocars were inserted to permit aortic dissection and creation of retroperitoneal tunnels to the femoral regions. After evacuation of the pneumoperitoneum, an 8-cm midline incision was made to allow a side-to-end aortic anastomosis. The patient's postoperative period was uncomplicated by any cardiopulmonary problems despite his history of three myocardial infarctions; the patient had minimal pain that allowed for a quick return to ambulation. This procedure is minimally invasive and appeared to simplify the postoperative period in our patient. It could become the procedure of choice for certain patients with aortoiliac disease.

Anastomosis, Surgical↗
PubMed1993

Laparoscopic inguinal herniorrhaphy: an individualized approach.

Between March 1991 and December 1992, we treated 63 patients with symptomatic inguinal hernias using a laparoscopic transabdominal preperitoneal approach adapted from Nyhus' technique. Treatment was individualized according to the classification of groin hernias described by Nyhus. We treated 32 type II hernia defects (indirect hernia) by preperitoneal closure of the internal ring with two to four stitches of 0-Prolene. Eighteen type IIIA (direct), three type IIIB (large indirect with weak posterior wall), and 10 type IV (recurrent) hernias were treated by fixing a prolene mesh with 0-Prolene sutures and staples from the pubic tubercle medially to the lateral aspect of the internal ring (including the cord into the mesh) laterally. The mesh was secured to the transversalis fascia and muscle and inferiorly to Cooper's ligament. No peroperative complications occurred. One patient had testicular pain of 1 week's duration after treatment of a type IV hernia. No mortality was recorded. Patients took, on an average, parenteral analgesia once (range, 0-5) and two enteral analgesics (range, 0-6). With a median follow-up of 8 months (range, 1-21), no recurrences were noted. Results are encouraging, and longer follow-up will determine the long-term efficacy of this procedure.

Adolescent↗