In vitro evaluation of the accuracy of open-configuration MRI in endovascular techniques.

The purpose of this study was to determine the accuracy of an interventional magnetic resonance imaging (iMRI) system to position an endovascular catheter in an in vitro model that simulated an infrarenal aortic aneurysm. Adequate visualization of abdominal aortic aneurysms (AAAs) was shown previously in humans. A dedicated near-real-time imaging protocol readily available on a Signa SP 0.5T open configuration MRI unit (General Electric Medical Systems, Milwaukee, WI, USA) was used to image the AAAs of ten human volunteers. A pulsatile in vitro model that simulated an AAA was built, which included the kidneys, the renal arteries, the aorta, and the iliac arteries. A catheter was advanced to a predetermined target through one of the iliac limbs of the model. Using two different techniques, the accuracy with which an interventionist could position the endovascular catheter under the near-real-time guidance of the iMRI system was evaluated. The AAAs of all ten patients were visualized, including the aneurysm wall, the thrombus within it, and the residual lumen, while maintaining adequate contrast, signal, and imaging speed. The position of the catheter was evaluated on target in 42 in vitro procedures. This series of tests showed an average accuracy of 1 mm for catheter positioning. The near-real-time imaging mode of the iMRI system enabled satisfactory evaluation of human AAAs, and it showed great accuracy for catheter positioning in the in vitro model. These results provide optimism regarding the potential of iMRI in endovascular surgery.

The three-dimensional video system; an essential component of the endosurgical suite of the future.

Minimal access surgery has revolutionized the practice of surgery. It has been shown that patients may experience less postoperative discomfort, shorter hospitalization, and quicker recuperation. The centerpiece of this revolution resides in the development of optical equipment which allowed the surgeon and his or her assistants to visualize on two-dimensional (2-D) monitors the site of the procedure to be performed. However, as techniques become more complicated, there is more need for accurate depth perception. In other surgical disciplines like neurosurgery, otorhynolaryngology, and microvascular surgery, for instance, magnification is used to perform fine manipulations; to prevent loss of depth perception, microscopes are binocular. They permit stereoscopic vision with accurate depth perception. We have used and evaluated a three-dimensional (3-D) videocamera system, designed for laparoscopy, in an in vitro situation, in the experimental laboratory and clinically, and we report our experience in this chapter. We also discuss the rationale for use of 3-D video systems.

Laparoscopic aorto-iliac surgery: present status and future perspectives.

Over the past few years, the concept of "minimally invasive surgery" has generated a significant interest in the field of cardiovascular surgery. Congenital heart diseases such as patent ductus arteriosus, vascular ring or atrial septal defect have been treated using video-assisted technology. Although patients have undergone mitral valve replacement and repair, the focus of interest in the development of video-assisted cardiac surgery is in the treatment of coronary artery disease.

History and perspectives in laparoscopic vascular surgery.

Laparoscopic techniques have changed the face of many surgical specialties. In this article, we describe the evolution of laparoscopy in vascular surgery from its beginning in the early 1990s. We discuss the present laparoscopic techniques for treatment of aortoiliac disease, their advantages and limitations. We suggest the vascular surgeon learns laparoscopy on the model used in general surgery a decade ago. Although more studies are needed to further define the role of laparoscopy, present indications can be found in those patients with TASC III and IV occlusive lesions and in patients with abdominal aortic aneurysms who are candidate to tube grafts or aortobifemoral bypass. With further refinements in technology (anastomotic stapling device, robotics) and techniques, laparoscopy should replace many open surgeries presently done for aortoiliac disease but will also have to be considered for treatment of mesenteric disease as described in the text.

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.

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.

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.

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.

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.

Technological advances in laparoscopic aorto-occlusive surgery.

Minimally invasive surgery (MIS) has been recognized as increasingly beneficial to patients undergoing various cardiovascular surgical procedures. Cardiac applications with MIS techniques and technologies are being shown as beneficial in heart valve replacement and in coronary artery bypass. In vascular surgery, benefits are being reported for endoscopic saphenous vein harvesting as well as endoscopic ligation of incompetent perforators. Since 1993, applications of laparoscopy to aortic surgery have been reported. Until these reports, percutaneous interventional procedures have been the mainstay of MIS vascular work for aortoiliac disease. Reported laparoscopic techniques have ranged from laparoscopically assisted techniques to procedures performed completely laparoscopically. Several studies show that laparoscopic aortic surgery is feasible. These show the known advantages of MIS for patients, with decreased use of analgesics, shortened ileus, earlier ambulation, and shortened length of stay. Laparoscopy has been showing a growing role in the armamentarium of the modern vascular surgeon.

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.

Laparoscopic cholecystectomy: a report of 60 cases.

From April to August 1990, 60 patients underwent laparoscopic cholecystectomy. Patients with biliary colic were included, but those who had florid acute cholecystitis, morbid obesity or scars in the upper portion of the abdomen were excluded. Three patients had acute cholecystitis, 56 had chronic cholecystitis and 1 had hydrops of the gallbladder. Nineteen patients had had previous lower abdominal surgery. Five patients did not require analgesia, but the remainder needed parenteral analgesia on an average of 1.7 occasions and enteral analgesia on an average of 1.8 occasions. There were no intraoperative complications, and no patient had the procedure completed by standard surgery. Postoperative hospital stay averaged 2.5 days. The mean follow-up was 39 days. Few postoperative complications were noted: two patients suffered from ileus; two patients had biliary colic postoperatively (one required endoscopic sphincterotomy with stone extraction, and in the other no common-duct stones were seen on retrograde cholangiography); one patient had an intra-abdominal abscess, which was drained percutaneously; and one patient complained of upper abdominal pain that was incisional in origin. Laparoscopic cholecystectomy should be considered the procedure of choice for elective treatment of uncomplicated symptomatic gallstone disease.

Hot-tip laser angioplasty for peripheral vascular disease: clinical experience with 18 patients.

Between May 1988 and March 1989, the authors treated 18 patients who suffered from disabling claudication or rest pain. They used the laser hot-tip angioplasty technique, in which a metal tip on the laser transforms laser energy into heat. Nineteen lower extremities were so treated. Six patients had suffered iliac occlusion, 11 had disease in the superficial femoral artery and 1 in the popliteal artery. Laser angioplasty was successful in 7 of 13 lower limbs with infrailiac lesions and in 4 of the 6 limbs with iliac artery occlusion; the other 2 underwent bypass grafting (aortoiliac in 1 and aortobifemoral in the other). No loss or limb or death occurred, but immediate complications of perforation or dissection were frequent.

Laparoscopic inguinal herniorrhaphy.

Between Mar. 13 and Sept. 16, 1991, the authors performed 10 inguinal herniorrhaphies laparoscopically. Two patients with a type II hernia (indirect with dilated internal ring but intact posterior inguinal wall) had laparoscopic preperitoneal closure of the internal ring with interrupted 0-Prolene. Seven patients had a type IIIA hernia (direct), and one patient had a large type IIIB hernia (indirect with dilated internal ring and medial encroachment or destruction of transversalis fascia of Hesselbach triangle). They all underwent laparoscopic preperitoneal placement of Prolene mesh, which was fixed in place with interrupted 0-Prolene sutures. All patients recovered promptly, with less pain and minimal limping, resulting in high patient acceptance of the procedure. There were no complications. Although no recurrence was noted and the technique appears sound, it is too early to predict its long-term success. At present, the preperitoneal approach is difficult to perform because of lack of appropriate instrumentation. The surgeon who plans to perform such a procedure must be familiar with the anatomy. We suggest that every potential candidate for laparoscopic inguinal hernia repair should be apprised of the advantages and disadvantages of this approach. A research consent form should be read and signed by every patient.

Laparoscopic cholecystectomy: a review of 258 patients.

Between Apr. 18, 1990, and Apr. 26, 1991, 258 patients were treated for symptomatic cholelithiasis by laparoscopic cholecystectomy. In 252 patients the diagnosis was chronic calculous cholecystitis, in 3 acute cholecystitis and in 3 hydrops of the gallbladder. There were no deaths. Major complications occurred early in the study--one patient suffered a cardiac arrest because of gas embolism and one had leakage from the stump of the cystic duct, which was treated by percutaneous drainage. Both patients recovered without further complications. The hospital stay averaged 2.9 days. The authors discuss important technical points for the safe performance of laparoscopic cholecystectomy and consider the results obtained by leading groups in the field and by one multicentre survey in the United States. Almost 25,000 cases of laparoscopic cholecystectomy are evaluated.

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.

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.

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.

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.

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.