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Background: Laparoscopic surgery is associated with reduced surgical trauma, and therefore with a less acute phase response, as compared with open surgery. Impairment of the immune system may enhance surgical infections, port-site metastases, and sepsis. The objectives of this review was to assess immunologic consequences of benign laparoscopic surgery and to highlight controversial aspects., Methods: A literature search on stress response to nonmalignant laparoscopic and open surgery was conducted using the MEDLINE and Cochrane databases. Cross-references from the reference list of major articles on the subject were used, as well as manuscripts published between 1993 and 2002., Results: Local (i.e., peritoneal) immune function is affected by carbon dioxide pneumoperitoneum. The production of tumor necrosis factor and the phagocytotic capacity of peritoneal macrophages are less lowered. The systemic stress response, as determined by delayed-type hypersensitivity response and leukocyte antigen expression on lymphocytes, shows a preservation of immune function after laparoscopic surgery, as compared with conventional surgery., Conclusions: Intraperitoneal carbon dioxide insufflation attenuates peritoneal immunity, but laparoscopic surgery is associated with a lower systemic stress response than open surgery.

Background: This study was performed to evaluate the (long-term) morbidity associated with hand-assisted laparoscopic surgery (HALS) for various indications., Methods: HALS procedures for various indications were evaluated prospectively from 1995 to 2002. The primary outcome parameters were postsurgical complications and the development of incisional hernias., Results: Twenty-six splenectomies, 51 hand-assisted laparoscopic donor nephrectomies (HLDN), 34 segmental bowel resections, 29 proctocolectomies, and 10 emergency colectomies were evaluated. A Küstner or Pfannenstiel incision was used for handport placement. Minor complications (i.e., wound complications, urinary tract infection) occurred in 15%, 12%, 26%, 7%, and 33% of the patients after, respectively, splenectomy, HLDN, bowel resection, proctocolectomy, and emergency colectomy. Major complications (i.e., hemorrhage, anastomotic leakage) occurred in 15% and 12% of the patients after, respectively, bowel resection and proctocolectomy. Incisional hernias occurred in six patients (4%), all after a wound complication in the Küstner incision., Conclusion: HALS is fast, safe, and feasible for various indications, especially HLDN and (procto-)colectomies. Little advantage can be expected when HALS is applied in splenectomy and segmental bowel (sigmoid) resection.

The safety of the laparoscopy setup is an important issue to guarantee continuous quality of laparoscopic interventions. Important issues are visualization, the insufflator and especially electrosurgery. Appropriate training of the OR personnel and clear responsibilities should be defined. Checklists are advised.

Background: The aim of this study is to create new ergonomic guidelines for the design of laparoscopic needle holders., Methods: An ergonomic literature study, observations in the operating room, handle-shaft angle measurements, and anthropometric data were used to compile new ergonomic criteria, specified to the function of a laparoscopic needle holder. Based on these guidelines a new needle holder was designed. The prototype and three currently available needle holders were evaluated according to the new guidelines. In addition, a pelvi-trainer test was done to measure the extreme wrist excursions., Results: The ergonomic evaluation of three commonly used handles and the new prototype indicate that the new handle is an ergonomic improvement in the field of laparoscopic needle holders: only the new handle satisfies all criteria. This is validated by the results of the pelvi-trainer test, which showed that the new prototype significantly (p <0.001) reduced the extreme wrist excursions., Conclusion: The new design guidelines for a laparoscopic needle holder result in an ergonomic improvement of the instrument.

Background: Compared to open surgery, minimally invasive surgery (MIS) relies heavily on advanced technology, such as endoscopic viewing systems and innovative instruments. The aim of the study was to objectively compare three technologically advanced laparoscopic viewing systems with the standard viewing system currently used in most Dutch hospitals., Methods: We evaluated the following advanced laparoscopic viewing systems: a Thin Film Transistor (TFT) display, a stereo endoscope, and an image projection display. The standard viewing system was comprised of a monocular endoscope and a high-resolution monitor. Task completion time served as the measure of performance. Eight surgeons with laparoscopic experience participated in the experiment., Results: The average task time was significantly greater (p <0.05) with the stereo viewing system than with the standard viewing system. The average task times with the TFT display and the image projection display did not differ significantly from the standard viewing system., Conclusion: Although the stereo viewing system promises improved depth perception and the TFT and image projection displays are supposed to improve hand-eye coordination, none of these systems provided better task performance than the standard viewing system in this pelvi-trainer experiment.

Background: This study was performed to assess the optimal display location of a flat-screen monitor for laparoscopy. It was also performed to assess the posture (objective), opinion, and preference (subjective) of subjects using a flat-screen monitor positioned in the optimal display location and a cathode-ray tube monitor on a tower next to the operating table (current situation)., Methods: Twelve surgeons performed cholecystectomies using the two display systems alternately. The postures of the operator and the assistant were assessed by an infrared video analysis system., Results: The posture of the assistant is significantly better when using a flat-screen monitor [more neutral head flexions (p = 0.036) and neutral neck torsions (p = 0.012)]. No significant differences were found for the posture of the operator. The operators and assistants felt more comfortable when using a flat-screen monitor (p = 0.008) and they preferred this display to the use of a monitor on a tower., Conclusions: The use of flat-screen monitors is better for the physical and psychological comfort of the users, even though the technical performance is inferior in comparison with that of regular monitors.

Purpose: The aim of this study was to find the ergonomically optimal operating surface height for laparoscopic surgery in order to reduce discomfort in the upper extremities of the operators and the assistants. The operating surface height was defined as the level of the abdominal wall of a patient with pneumoperitoneum., Materials and Methods: Two pelvi-trainer tests were performed. One test was performed on six different operating surface heights. The (extreme) joint excursions of the shoulder, elbow, and wrist were measured by a video analysis method. Another test was performed by holding a laparoscope for 15 minutes while an electromyelograph of the biceps brachii was made. The results of both tests were evaluated subjectively by a questionnaire., Results: The ergonomically optimal operating surface height lies between a factor 0.7 and 0.8 of the elbow height of the operator/assistant. At this height, the joint excursions stay in the neutral zone for more than 90% of the total manipulation time, and the activity of the biceps brachii when holding the laparoscope stays within 15% of the maximum muscle activity., Conclusions: The operating surface height influences the (extreme) upper joint excursions of the surgeon. The ergonomically optimal operating surface height reduces the discomfort in the shoulders, back, and wrists of the surgeon during laparoscopic surgery. This optimal table height range for laparoscopic surgery is lower than those currently available.

Background: Recent studies have shown that the shape of most instrument handles causes user discomfort and that none of the handles currently available on the market satisfies all ergonomic criteria. Therefore, we designed a handle with improved usability; i.e., it is easier to manipulate and its use entails less risk of injury for the operator. The aim of this study was to demonstrate that the intended improvements of the new design were successful., Methods: Six handles representative of the types that are currently available were compared with the new version. Eight surgeons used the seven handles during a precision task and a rough task in a pelvi-trainer. A questionnaire and video analyses were used to assess the usability of the handles., Results: Based on the responses to the questionnaire, we determined that there were significant differences between the new handle and the Aesculap handle (means of rotation and angle between handle and shaft). No significant differences were found between the new handle and the five other handles. The video analyses (documenting extreme vs neutral wrist excursions) showed significant differences between the new handle and the six other handles., Conclusion: Compared to the six existing handles, the new handle has significantly improved usability; in particular, its hinged design obviates the need to make extreme wrist excursions.

Within a Dutch research program on minimally invasive surgery, a large literature survey has been carried out. This article describes the state of the art in research on observation in laparoscopy. It gives an overview of factors impeding the surgeon and technical developments designed to overcome these problems. A large number of journals, proceedings, patents, and books starting from the year 1991 have been consulted. The survey was completed with a thorough MEDLINE search. The survey showed that many authors have an incomplete background in the fundamentals of visual perception. This leads to a lack of understanding and to the design of supporting aids that often are not very useful. The new aspect of this study is that it gives a complete and structured overview of laparoscopic observation problems and current solutions. The observation problems are structured according to visual perception theory. The solutions are critically considered, and their benefits and drawbacks are identified. The study shows that the benefits of stereo-endoscopes and motorized endoscope positioners are questionable. The addition of shadows and movement parallax is still a very important research topic.

Background: Advanced laparoscopic surgery is complex and time-consuming. Achieving consistent efficacy and safety throughout the entire procedure is always a problem. For this reason, hand-assisted laparoscopic surgery (HALS) was developed., Methods: Devices were designed to allow manual access to the abdomen through the utility laparotomy. By using one hand in the abdomen during laparoscopy, the surgeon regains direct tactile sensation and acquires improved hand-eye coordination. The safety of the individual devices has been tested in RCT for the registration of the individual devices. An index known as Surgical Action Efficiency was calculated for in six patients undergoing laparoscopic colon resection and six patients with hand-assisted colon resections., Results: All of the registered devices are safe. Surgical Action Efficiency for the laparoscopy group was 55 +/- 14%; for the HALS group, it was 71 +/- 4%. This result is statistically significant (p < 0.05)., Conclusion: HALS is a safe and efficient method by which it is possible to combine the established convenience and safety of open surgery with the advantages of minimally invasive surgery.

Purpose: To determine the most efficient technique for performing a colectomy, we used the methodology of time-motion analysis., Methods: The efficiency of five hand-assisted and six regular laparoscopic colectomies and one open colectomy, performed by four surgeons in three different hospitals, was measured. The open colectomy was analyzed as a reference procedure., Results and Conclusions: The hand-assisted laparoscopic technique was the most efficient. Hand-assisted laparoscopy was therefore less time consuming than laparoscopic surgery. Open surgery was the fastest technique, because the time for every surgical motion is a factor of three shorter than for the two laparoscopic techniques.

Purpose: The balloon dilator is used in a variety of minimally invasive preperitoneal and retroperitoneal operations. In this study, we compared the ability to create an extraperitoneal cavity using a balloon spacer in patients with and without previous abdominal surgery undergoing laparoscopic bladder neck suspension., Patients and Methods: This prospective study included 38 patients in total, 15 of whom had had previous abdominal wall surgery and 23 who had not. A balloon spacer technique was used to develop the extraperitoneal space., Results: In 80% of the patients with previous surgery, the introduction of the balloon spacer was recorded as simple; in 20%, it was considered difficult. In 78% of the patients without previous surgery, the introduction of the balloon spacer was recorded as simple, in 17% it was difficult, and in 4% it failed. In 80% of the patients with previous surgery, the extraperitoneal view was good or acceptable, in 20% it was poor, and in 13% it failed. In 92% of the patients without previous surgery, the extraperitoneal view was good or acceptable, in 4% it was poor, and in 4% dilatation failed. Morbidity was equally divided between the groups., Conclusions: Previous abdominal surgery is not a contraindication to laparoscopic extraperitoneal surgery using a balloon spacer. The approach carries low morbidity, similar to that in patients without previous abdominal surgery.

This study determined which types of laparoscopic instruments are most often used in Europe, why they are being used, and what problems exist while using the instruments. The handles were also evaluated according to ergonomic design criteria. A questionnaire was send to 62 experienced surgeons in 19 countries. The laparoscopic instruments were divided into four groups: instruments with similar functionality and handgrip model were grouped together. Eight questions were asked for every group about the type of instrument (disposable, reusable, or semireusable), the type of handle, the reason for using a specific instrument, and the experience of discomfort while using the instrument. The handles of the instruments of the group that were associated with the greatest discomfort were ergonomically evaluated on eight aspects (dimensions, angles, and control). Half of the questionnaires were returned. In every group, about 80% of the instruments the surgeons employed were reusable. The chief reason for using a specific type was the good cost-quality of the product and satisfying experiences with other products of the brand. The discomfort was pressure on thumb and fingers (scissors handle) and fixating the tip (ratchet). The handle of the instruments that causes the most discomfort met only three of the eight ergonomic requirements. Most of the laparoscopic instruments employed by surgeons in Europe are reusable. A significant number of the instruments cause discomfort. These instruments do not meet standard ergonomic requirements.

Within a Dutch research program on minimally invasive surgery, a large literature survey has been carried out. This article describes the state of the art in research on manipulation in laparoscopy. It gives an overview of factors impeding the surgeon and technical developments designed to overcome these problems. Starting from the year 1991, a large number of journals, proceedings, patents, and books have been consulted. The survey was completed with a thorough MEDLINE search. The impeding effects have been subdivided into two groups: transformation of spatial and grasping movements of the hand. The article gives an overview of these effects and of supporting aids that have been developed. The studies show that many aids are based on a technology-driven rather than a clinically-driven approach. The development of simple instruments that can be used for a large range of tasks instead of only one is still a very important topic of research.

Laparoscopic splenectomy claims a number of advantages over open surgery: less trauma, quicker recovery, and faster return to normal activity. On the other hand, laparoscopic splenectomy is complex and time consuming, and so far, many surgeons are reluctant to perform such an operation. A new device was designed to give manual access to the abdomen through a utility laparotomy. By using one hand in the abdomen during laparoscopy, the surgeon regains direct tactile sense and hand-eye coordination. A pilot study to assess the feasibility of this method has been performed in 22 patients. The operation could be completed easily in 21 patients (95%). The average blood loss was 230 mL, and the average postoperative stay was 3.9 days. With this simple, inexpensive method, it is possible to combine the established convenience, safety, efficacy of open surgery with the advantages of minimally invasive surgery.

Depth perception is closely linked to the ability to explore. Previously described laboratory experiments showed the advantage of linking the motions of the laparoscope directly to the head movements of the surgeon. Additionally, it was found that the laparoscope should be mechanically supported instead of manually (by an assistant). This article describes three stages in the design and evaluation of a practical mechanism with which to link the motions of the laparoscope directly to the head movements of the surgeon. First, a description is given of the perceptual and technical considerations. Second, a laboratory experiment is described investigating the validity of the proposed suggestions. Last, a prototype was built that was tested in a practical setting.

Background: Sensory feedback is reduced considerably in minimally invasive procedures by the interposition of instruments, causing loss of direct manual contact with the tissue. The purpose of this study was to evaluate the feedback quality of commercially available reusable and disposable laparoscopic dissectors., Methods: A total of 31 participants were asked to feel a simulated arterial pulse with their bare fingers and through laparoscopic dissectors, tweezers, an orthopedic forceps, and a laparoscopic low-friction prototype. The absolute sensory threshold was determined by the psychophysical method of limits., Results: The sensory feedback quality was significantly better for the reusable dissectors tested than for the disposable dissector (p < 0.001). Nevertheless, the reusable dissectors were at least eight times less sensitive than bare fingers. Furthermore, sensitivity qualities were highly variable, depending on the dissector tested., Conclusions: This study showed that the overall sensitivity loss through instruments could be accurately assessed, proving that the sensory feedback for commercially available instruments was low compared to bare fingers. The good sensory feedback results of the prototype indicated that careful design could decrease the overall sensitivity loss.

Retroperitoneal endoscopic nephrectomy with the patient in the prone position was performed in 12 patients. Indications for this procedure were end-stage kidneys with ureteropelvic junction stenosis or distal ureteric obstruction, nonfunctional kidneys with drug resistant renin-mediated hypertension, and distal ureter malignancy. The retroperitoneal area was exposed using an open surgical technique in combination with the use of a liquid-filled dissection balloon. Removal of kidney tissue was performed with a morcellator through one of the ports. On average, the operating time was 210 min (range 160-480 min) to complete a one-sided nephrectomy. No major complications occurred. Mean hospital stay in this series was 6.6 days, and the follow-up period was uncomplicated in all cases. Retroperitoneal endoscopic nephrectomy with the patient in the prone position is an acceptable alternative to open nephrectomy in selected indications.

Background: Total extraperitoneal laparoscopic surgery is an alternative to the laparoscopic transperitoneal route; however, its effects on hemodynamics have not been adequately studied. This experimental study compared the effects of intraperitoneal insufflation and extraperitoneal insufflation on hemodynamics and oxygen transport., Methods: Sixteen pigs were randomly assigned for intraperitoneal insufflation or extraperitoneal insufflation with 15 mmHg carbon dioxide. Hemodynamic and oxygen transport parameters were taken during an hour of insufflation and analyzed for statistical differences., Results: During extraperitoneal CO2 pneumoperitoneum central venous filling pressures (central venous pressure, pulmonary capillary wedge pressure and mean pulmonary arterial pressure) and end-tidal CO2 increased slower but to a similar magnitude in comparison to intraperitoneal insufflation. Cardiac output and indices of oxygen consumption and oxygen delivery were equally affected by both types of insufflation. Arterial CO2 pressure increased significantly more during intraperitoneal insufflation., Conclusion: The data from this study suggest that extraperitoneal insufflation might result in less cardiovascular impairment than intraperitoneal insufflation.

Background: Disadvantages related to CO2 pneumoperitoneum have led to development of the abdominal wall retractor (AWR), a device designed to facilitate laparoscopic surgery without conventional pneumoperitoneum (15 mmHg CO2). We investigated the effects of the AWR on hemodynamics and gas exchange in humans. We also investigated whether the use of an AWR imposed extra technical difficulties for the surgeon. A pilot study revealed that cholecystectomy without low-pressure pneumoperitoneum was technically impossible., Methods: A prospective randomized controlled trial: Twenty patients undergoing laparoscopic cholecystectomy were randomly allocated into group 1: AWR with low-pressure pneumoperitoneum (5 mmHg), or group 2: conventional pneumoperitoneum (15 mmHg)., Results: Surgery using the AWR lasted longer, 72 +/- 16 min (mean +/- SD) vs 50 +/- 18 min compared with standard laparoscopic cholecystectomy. There were no differences between the groups with respect to hemodynamic parameters, although a small reduction of the cardiac output was observed using conventional pneumoperitoneum (from 3.9 +/- 0.7 to 3. 2 +/- 1.1 l/min) and an increase during AWR (from 4.2 +/- 0.9 to 5.2 +/- 1.5 l/min). Peak inspiratory pressures were significantly higher during conventional pneumoperitoneum compared to AWR. A slight decrease in pH accompanied by an increase in CO2 developed during pneumoperitoneum and during the use of the AWR. In both groups arterial PO2 decreased., Conclusions: The results indicate that the view was impaired during use of the AWR and therefore its use was difficult and time-consuming. Possible advantages of this devices' effects on hemodynamics and ventilatory parameters could not be confirmed in this study.

Unlabelled: The dexterity pneumo sleeve is designed to provide abdominal access for the surgeon's hand while preserving pneumoperitoneum during laparoscopy. The first experience using the dexterity pneumo sleeve in colorectal surgery is reported., Methods: Four patients with diverticulitis and one with a dolichocolon had manually assisted laparoscopic sigmoid colectomy with the dexterity pneumo sleeve., Results: Assistance of the left hand, introduced through the dexterity device proved to be extremely helpful in identifying the plane of dissection in one patient with a large diverticular mass and in another with a colovaginal fistula. Mean operative time was 109 minutes, blood loss was 80 ml, and length of incision was 7.5 cm. Flatus reoccurred at the second postoperative day, bowel movement occurred on the third day after surgery, and patients were discharged after 4.8 days., Conclusions: With the dexterity pneumo sleeve, the tactile sensation is regained, which makes laparoscopic-assisted colectomy safer and faster.

Techniques for retroperitoneal endoscopic procedures with the patient in prone position were evaluated in experimental studies in the pig. Nephrectomy, para-aortic lymph node dissection, lumbar sympathectomy and assisted aorto-femoral bypass were performed and the experience is reported herein. The prone position contributes to the creation of the retroperitoneal working space and eliminates the need for extensive retraction and thus for additional ports. The modified open Hasson technique was found to be the preferred retroperitoneal access procedure.

Paraaortic lymph node sampling has been found to be efficient in the staging of genitourinary cancers. However, the complications associated with this procedure using the traditional transperitoneal or extraperitoneal approach are considerable. Developments in endoscopic technology and instrumentation have allowed an extraperitoneal approach. Presented is a porcine model for extraperitoneal endoscopic paraaortic lymph node dissection as a staging procedure for genitourinary cancers. The pig is placed in a prone position, and an extraperitoneal pneumoperitoneum is created. Using a three-port technique, we were able to remove almost 95% of all paraaortic lymph nodes laparoscopically without any complications. The prone position allows for a fast and safe procedure because it minimizes the need for extra entry ports and gives a clear view, unobstructed by the bowel, of the back wall of the abdomen.

Retroperitoneal endoscopic lumbar sympathectomy was performed in four pigs in the prone or lateral position to study the feasibility of these new approaches. Positioning, port placement and the dissection technique are described in detail. In nine patients retroperitoneal endoscopic lumbar sympathectomy, using the lateral position technique, was performed. The importance of port placement and dissection techniques for visualisation of the sympathetic chain are emphasised. The endoscopic retroperitoneal approach enables the sympathetic chain to be accurately localised whilst enhanced endoscopic vision aids dissection. Retroperitoneal endoscopic lumbar sympathectomy is a feasible technique offering patients the benefits of the minimally invasive approach.

During laparoscopy elevations in arterial pressure and a decrease in cardiac output have been reported. Laparoscopic surgery performed in the prone position may be advantageous for some surgical procedures, but the hemodynamic effects of pneumoperitoneum in this position have not been studied. We studied the effects of different levels of increased intraabdominal pressure on hemodynamics and oxygen transport in eight pigs in the prone and the supine position. Increases in intraabdominal pressure did not result in decreased cardiac output or in a reduction of oxygen transport and consumption in either position. These results suggest that laparoscopy in the prone position does not result in more severe hemodynamic depression than laparoscopy in the supine position.

Obtaining a clear view during laparoscopic surgery in the posterior abdominal cavity, on the abdominal backwall, or during colon surgery is time consuming and therefore one of the major objections to these procedures. In an experimental setting we positioned the animals in the prone position using the abdominal flanks to introduce the trocars. Our experience with this position is that a clear and unobstructed view of the abdominal back wall and the large intestines is obtained, facilitating laparoscopic procedures in these areas.

Rapid implementation of left ventricular assistance without thoracotomy for temporary support of patients with severe, life-threatening, acute cardiac power failure potentially expands applications of such support devices. A thoracoscopic technique for direct cannulation of the left atrium is described. In healthy closed-chest pigs, it proved a feasible method for effective volume unloading of the left ventricle.

Osteochondral defects in the rabbit knee were filled with a TCP-collagen mixture. In the femoral condyles a fibrous tissue was formed in the defects similar to that seen in control defects. In the tibial plateau defects were made with penetration of the underlying epiphysis. Repair tissue was formed resembling articular cartilage.

This thesis describes new concepts pertaining to the continent ileostomy. The aim of the study was twofold: to counter valve desinvagination and to simplify pouch construction. In Chapter 1 a survey is given of the history, the present situation of the technique and the complications of the continent ileostomy. It appears that on the one hand the operation improves the quality of the patient's life, but on the other hand the operation gives rise to many complications. The number of complications quoted in the literature varies and has been reported to be as high as 43%. Most of the time this led to repeat surgery, with equally uncertain results. This is the reason why the operation is not very frequently performed. Most of the time the complications concern the valve system and to a lesser degree the reservoir. In order to obtain a better insight into the origin of and possible gain better control over these complications an investigation was carried out on laboratory animals. This investigation involved: the complications of the valve system, the effect of the suturing method on the function of the reservoir and the simplification of the construction of the reservoir. In Chapter 2 the aim of the investigation was formulated in three questions. 1. Is it possible to diminish the chance of complications of the valve system of the continent ileostomy? 2. Does the method of suturing influence the function of the reservoir? 3. Is it possible to simplify the construction of the reservoir, so that the duration of the operation can be shortened? Chapter 3 is the general materials and methods section. Chapter 4 is about the research on the valve system. Up to now, no method of suturing the valve has consistently produced results good enough to make subsequent re-operations unnecessary. In this study two types of valve experiments have been carried out. First the feasibility of circumventing the problems of the nonpermanent form of the valve was investigated combining a short papilla with a 10 centimeter long, anti-peristaltic sutured section of the ileum. The assumption was that permanence of the form would be more easily obtained in a shorter valve (2 centimeter instead of 5 centimeter). After an initial period of continence, incontinence occurred on the average after 10 months. Autopsy showed that the short papilla had disinvaginated.(ABSTRACT TRUNCATED AT 400 WORDS)

Complications of the nipple valve system used for continent urostomy and ileostomy basically consist of incomplete (or complete lack of) adhesion of the invaginated serosal surfaces of the valve. A novel concept in fixation of the valve by means of the intussusception of a newly developed biomaterial (processed dermal sheep collagen; PDSC) was tested. The implanted PDSC is characterized by induction of fibroblast invasion and formation of new collagen fibers, initial high tensile strength, bio-inertion and (slow) biodegradation. It was implanted between the serosal surfaces of the invagination in 14 dogs without the application of the commonly used staples and synthetic mesh. Good permanent fixation was obtained in all cases after the PDSC had been sutured in place. As the observation time advanced up to 2 years, an increased amount of newly formed collagen was seen anchoring the serosal surfaces firmly together via the implanted PDSC with apparent slow degradation. In none of the test animals did complications occur. The first clinical trial was successful.