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Biomedical subjects

H J Bonjer

Publications and source records attributed to H J Bonjer.

At least 37 records · Page 2Linked to original sources
PubMed2003

Laparoscopic resection of colonic cancer.

Laparoscopic resection of colonic cancer can be regarded as a safe and efficacious procedure. Short-term outcome is better after laparoscopic colectomy than after open colectomy. Long-term results of the first published randomized clinical trial indicate improved cancer related survival following laparoscopic resection of colonic cancer. However, patients included in this single center study were operated on by highly experienced laparoscopic surgeons and included relative small numbers of patients. Results of other large randomized controlled trials have to be awaited before laparoscopic resection can be recommended for colonic cancer. Higher in-hospital costs and a long learning curve hinder rapid implementation of laparoscopic colectomy into general surgical practice. Integration of laparoscopic surgery into surgical training programs is mandatory.

Colectomy↗
PubMed2002

Safe laparoscopic adhesiolysis with optical access trocar and ultrasonic dissection. A prospective study.

BACKGROUND: The objective of this clinical study was to examine the feasibility, safety, and adequacy of hemostasis of combined use of an optical trocar and ultrasonic dissection in laparoscopic adhesiolysis in patients with chronic abdominal pain. METHODS: In 105 patients, identification of anatomic layers of the abdominal wall, establishment of pneumoperitoneum, completeness of adhesiolysis, hemostasis, and complications and pain relief were studied. RESULTS: All abdominal wall layers could be determined during introduction as well as adherence of intraabdominal organs at the introduction site. Ultrasonic dissection enables an (almost) complete adhesiolysis in 103 (98%) patients and offered adequate hemostasis in 101 (96%) patients. Four perforations during laparoscopic adhesiolysis and no late (thermal) perforations were observed. CONCLUSIONS: With an optical trocar a safe introduction site of the abdominal wall can be chosen. The ultrasonic technique offers a sound adhesiolysis with adequate hemostasis and fewer thermal perforations and adds to feasibility and safety of laparoscopic adhesiolysis.

Abdominal Pain↗
PubMed2002

Tensile strength of mesh fixation methods in laparoscopic incisional hernia repair.

BACKGROUND: Fixation of the mesh is crucial for the successful laparoscopic repair of incisional hernias. In the present experimental study, we used a pig model to compare the tensile strengths of mesh fixation with helical titanium coils (tackers) and transabdominal wall sutures. METHODS: Thirty-six full-thickness specimens (5 x 7 cm) of the anterior abdominal wall of nine pig cadavers were randomized for fixation of a polypropylene mesh (7 x 7 cm) by either tackers or transabdominal wall sutures. The number of fixation points varied from one to five per 7-cm tissue length, with distances between fixation points of 2.3, 1.8, 1.4, and 1.2 cm, respectively. The force required to disrupt the mesh fixation (tensile strength) was measured by a dynamometer. Statistical analysis was performed using the Wilcoxon test and the Spearman rank correlation test. RESULTS: The mean tensile strength of mesh fixation by transabdominal sutures was significantly greater than that by tackers for each number of fixation points: 67 N vs 28 N for a single fixation point (p <0.001), 115 N vs 42 N for two fixation points (p <0.001), 150 N vs 63 N for three fixation points (p <0.05), 151 N vs 73 N for four fixation points (p <0.05), and 150 N vs 82 N for five fixation points (p <0.05). Increasing the number of fixation points over three per 7 cm (distance between fixation points of 1.8 cm) did not improve tensile strength. CONCLUSION: The tensile strength of transabdominal sutures is up to 2.5 times greater than the tensile strength of tackers. Therefore, the use of transabdominal sutures for mesh fixation appears to be preferable for laparoscopic incisional hernia repair.

Abdominal Wall↗
PubMed2002

Complications and feasibility of laparoscopic adhesiolysis in patients with chronic abdominal pain. A retrospective study.

BACKGROUND: A retrospective study was done to determine whether laparoscopic adhesiolysis benefits patients with chronic abdominal pain. Factors that influence complications and feasibility of laparoscopic adhesiolysis were evaluated. METHODS: 174 consecutive operations in 157 patients were retrospectively analyzed for factors which might influence the complication rate and the feasibility of laparoscopic adhesiolysis. RESULTS: In 128 out of 174 procedures a complete adhesiolysis was performed. We had to accept an incomplete adhesiolysis in 39 other patients and in 7 patients a primary conversion was needed. We noticed 16 major complications. Two patients died. Relief of pain was recorded in 80% of patients after short follow-up. The number of previous abdominal operations and patient age significantly affected the outcome of surgery. CONCLUSION: Laparoscopic adhesiolysis in patients with chronic abdominal pain seems to be a feasible and effective operation with considerable risk.

Abdominal Pain↗
PubMed2002

Impact of carbon dioxide and helium insufflation on cardiorespiratory function during prolonged pneumoperitoneum in an experimental rat model.

BACKGROUND: Experimental studies on laparoscopic surgery are often performed in rats. However, the hemodynamic and respiratory responses related to the pneumoperitoneum have not been studied extensively in rats. Therefore, the aim of this study was to investigate in spontaneously breathing rats the effects of CO2 and helium, insufflation pressure, and duration of pneumoperitoneum on blood pressure, arterial pH, pCO2, pO2, HCO3-, base excess, and respiratory rate. METHODS: Five groups of 9 Brown Norway rats were anesthetized and underwent CO2 insufflation (6 or 12 mmHg), helium insufflation (6 or 12 mmHg), or abdominal wall lifting (gasless control) for 120 min. Blood pressure was monitored by an indwelling carotid artery catheter. Baseline measurements of mean arterial pressure (MAP), respiratory rate, arterial blood pH, pCO2, pO2, HCO3-, and base excess were recorded. Blood gases were analyzed at 5, 30, 60, 90, and 120 min during pneumoperitoneum, and MAP and respiratory rate were recorded at 5 and 15 min and at 15-min intervals thereafter for 2 h. RESULTS: CO2 insufflation (at both 6 and 12 mmHg) caused a significant decrease in blood pH and increase in arterial pCO2. Respiratory compensation was evident since pCO2 returned to preinsufflation levels during CO2 insufflation at 12 mmHg. There was no significant change in blood pH and pCO2 in rats undergoing either helium insufflation or gasless procedures. Neither insufflation pressure nor the type of insufflation gas had a significant effect on MAP over time. CONCLUSION: The cardiorespiratory changes during prolonged pneumoperitoneum in spontaneously breathing rats are similar to those seen in clinical practice. Therefore, studies conducted in this animal model can provide valuable physiological data relevant to the study of laparoscopic surgery.

Animals↗
PubMed2002

Technical considerations and pitfalls in laparoscopic live donornephrectomy.

BACKGROUND: Recent developments in laparoscopic solid organ surgery suggest a possible reduction in postoperative discomfort and disability for kidney donors. Technical aspects and the influence of surgical experience in laparoscopic donor nephrectomy were evaluated. METHODS: The clinical outcome of 57 laparoscopic donor nephrectomies (LapNx) was compared with that for a historic control group of 27 open donor nephrectomies (OpenNx). RESULTS: Three conversions to open nephrectomy (5.2%) were necessary. Postoperative complications were minor and comparable in both groups. Patients who underwent laparoscopic surgery demonstrated significantly less postoperative pain and a shorter hospital stay, but operative time and warm ischemia time were significantly longer. Graft survival after LapNx was 100% during a median follow-up period of 13 months. Operative time for LapNx decreased considerably with experience gained and seemed to be less for right nephrectomy. Stenotic ureter-bladder anastomoses occurred after LapNx in four patients during the first half year (7.0%), but this problem seemed to be resolved after modification of the technique. CONCLUSION: LapNx is associated with less postoperative discomfort and improved convalescence.

Case-Control Studies↗
PubMed2002

Meta-analysis of techniques for closure of midline abdominal incisions.

BACKGROUND: Various randomized studies have evaluated techniques of abdominal fascia closure but controversy remains, leaving surgeons uncertain about the optimal method of preventing incisional hernia. METHOD: Medline and Embase databases were searched. All trials with a follow-up of at least 1 year that randomized patients with midline laparotomies to closure of the fascia by different suture techniques and/or suture materials were subjected to meta-analysis. Primary outcome was incisional hernia; secondary outcomes were wound dehiscence, wound infection, wound pain and suture sinus formation. RESULTS: Fifteen studies were identified with a total of 6566 patients. Closure by continuous rapidly absorbable suture was followed by significantly more incisional hernias than closure by continuous slowly absorbable suture (P < 0.009) or non-absorbable suture (P = 0.001). No difference in incisional hernia incidence was found between slowly absorbable and non-absorbable sutures (P = 0.75), but more wound pain (P < 0.005) and more suture sinuses (P = 0.02) occurred after the use of non-absorbable suture. Similar outcomes were observed with continuous and interrupted sutures, but continuous sutures took less time to insert. CONCLUSION: To reduce the incidence of incisional hernia without increasing wound pain or suture sinus frequency, slowly absorbable continuous sutures appear to be the optimal method of fascial closure.

Hernia, Ventral↗
PubMed2002

Mesh repair of incisional hernia: comparison of laparoscopic and open repair.

OBJECTIVE: To compare our results of open and laparoscopic mesh repair of incisional hernias. DESIGN: Retrospective cohort study. SETTING: Teaching hospitals, The Netherlands. SUBJECTS: All patients who had had a laparoscopic (n = 25) or an open (n = 76) mesh repair of incisional hernia between January 1996 and January 2000. INTERVENTIONS: Physical examination at the time of the study. MAIN OUTCOME MEASURES: Morbidity and recurrence. RESULTS: The groups were comparable. 11 patients (14%) developed postoperative infections after open repair and 1 (4%) after laparoscopic repair (p = 0.29). Median hospital stay was 5 days (range 1-19) in the open group and 4 (range 1-11) in the laparoscopic group (p = 0.28). The 2-year cumulative incidence of recurrence was 18% after open repair (median follow-up of 17 months (range 1-46) and 15% after laparoscopic repair (median follow-up of 15 months, range 1-44). Recurrences in the laparoscopic group were all among the first 7 cases in which the mesh was fixed with staples alone. CONCLUSION: There were fewer infections and hospital stay was shorter in the laparoscopic group, but not significantly so. Recurrence rates were comparable.

Adult↗
PubMed2002

The value of plasma markers for the clinical behaviour of phaeochromocytomas.

OBJECTIVE: Phaeochromocytomas (PCCs) are widely known for their clinical unpredictability. This study intends to define predictive plasma markers for their variable postoperative behaviour. Furthermore, the diagnostic accuracy of these plasma tests was determined. DESIGN AND METHODS: A retrospective correlative study was performed in a series of 83 operated and four autopsied patients in order to correlate preoperative catecholamine (CAT) levels of 103 PCCs with their clinical behaviour. In a subset of cases, chromogranin-A (Chr-A) and enzymes/precursors of the CAT biosynthesis were studied for their predictive value. RESULTS: Basal CAT levels were elevated in 81/87 instances (sensitivity: 93%). Four of six cases with normal measurements showed only medullary hyperplasia. Larger PCCs, particularly those showing necrosis, capsular and vascular invasion, secreted higher CAT levels. Bilateral, hereditary tumours were less productive than their unilateral counterparts. Extra-adrenal PCCs secreted significantly lower levels of epinephrine (EPI) than intra-adrenal tumours. Fourteen patients developed metastases. According to Kaplan-Meier estimations, patients with higher levels of dopamine, norepinephrine (NE) and aromatic l-amino acid decarboxylase as well as lower ratios of EPI/EPI+NE, had significantly shorter metastases-free intervals. Existence of preoperative hypertension, left ventricular hypertrophy and measured blood pressures showed significant positive relationships with CAT levels, but not with Chr-A. CONCLUSIONS: These data showed that plasma CAT measurement is a sensitive method in the diagnostic work-up of PCCs. Those tumours producing normal levels are commonly small and asymptomatic. Furthermore, certain secretion patterns are indicative of the presence of metastases as well as the size and site of sporadic and syndrome-related PCCs.

Adolescent↗
PubMed2001

Mechanical ventilation with positive end-expiratory pressure preserves arterial oxygenation during prolonged pneumoperitoneum.

BACKGROUND: Laparoscopic surgery usually requires a pneumoperitoneum by insufflating the abdominal cavity with carbon dioxide (CO2). Increased intraabdominal pressure causes diaphragmatic displacement resulting in compressed lung areas, which leads to formation of atelectasis, especially during mechanical ventilation. Application of positive end-expiratory pressure (PEEP) can maintain pulmonary gas exchange. The objective of this study was to investigate the effect of abdominal gas insufflation on arterial oxygenation during mechanical ventilation with and without PEEP in rats. METHODS: In experiment 1, two groups of six rats were continuously insufflated with CO2 at 12 mmHg for 180 min. Group 1 was ventilated with 8 cm H2O PEEP and group 2 had 0 cm H2O PEEP. Group 3 served as a control. This group had abdominal wall lifting and was ventilated with 0 cmH2O PEEP. In experiment 2, two groups of six rats had abdominal CO2 insufflation and were ventilated with or without PEEP during 180 min (group 4 and 5). In this experiment, abdomens were desufflated in both groups for 5 min at 60 and 120 min. Blood pressure monitoring and measurement of arterial pO2 was performed by placement of an indwelling carotid artery catheter in both experiments. RESULTS: In both experiments, paO2 values decreased significantly in insufflation groups that were ventilated with 0 cmH2O PEEP (groups 2 and 5). Insufflation groups ventilated with 8 cmH2O PEEP had paO2 values comparable to these of control group. There were no significant differences in mean arterial pressure between insufflation groups ventilated with or without PEEP. CONCLUSION: PEEP preserves arterial oxygenation during prolonged pneumoperitoneum in rats with minimal adverse hemodynamic effects.

Animals↗
PubMed2001

Endoscopic extraperitoneal repair of a Grynfeltt hernia.

There are three types of lumbar hernia: congenital, acquired, and incisional hernias. Acquired hernia can appear in two forms: the inferior (Petit) type and the superior type, first described by Grynfeltt in 1866. We report endoscopic extraperitoneal repair of a Grynfeltt hernia. A 46-year-old woman presented with a painful swelling in the left lumbar region that had caused her increasing discomfort. The diagnosis of Grynfeltt's hernia was made, and she underwent surgery. With the patient in a left-side decubitus position, access to the extraperitoneal space was gained by inserting a 10-mm inflatable balloon trocar just anteriorly to the midaxillary line between the 12th rib and the superior iliac crest through a muscle-splitting incision into the extraperitoneal space. After the balloon trocar had been removed a blunt-tip trocar was inserted. Using two 5-mm trocars, one above and another below the 10-mm port in the midaxillary line, the hernia could be reduced. A polypropylene mesh graft was introduced through the 10-mm trocar and tacked with spiral tackers. The patient could be discharged the next day after requiring only minimal analgesics. At this writing, 2 (1/2) years after the operation, there is no sign of recurrence. This Grynfeltt hernia could safely be treated using the extraperitoneal approach, which obviates opening and closing the peritoneum, thereby reducing operative time and possibly postoperative complications.

Endoscopy↗
PubMed2001

Oncologic implications of laparoscopic and open surgery.

Although instrumental manipulation and mechanical tumor cell spillage seem to play the major role in port-site metastases from laparoscopic cancer surgery, minimally invasive procedures are used more and more in the resection of malignancies. However, port-site metastases also have been reported after resection of colon cancer in International Union Against Cancer (UICC) stage I [2, 14]. Therefore, changes in the peritoneal environment during laparoscopy also might influence intra- and extraperitoneal tumor growth during laparoscopy and pneumoperitoneum. Different results of experimental studies presented at the Third International Conference for Laparoscopic Surgery are analyzed and discussed.

Animals↗
PubMed2001

Short-term impact of carbon dioxide, helium, and gasless laparoscopic donor nephrectomy on renal function and histomorphology in donor and recipient.

BACKGROUND: Laparoscopic donor nephrectomy has the potential to increase the number of living kidney donations by reducing donor morbidity. However, studies have shown that raised intraabdominal pressure can result in transient renal dysfunction. Therefore, laparoscopically procured kidneys might be at higher risk for suffering a period of ischemia during pneumoperitoneum. The objective of this study was to investigate the short-term impact of pneumoperitoneum used for laparoscopic donor nephrectomy on renal function and histomorphology in donor and recipient. METHODS: EXPERIMENT 1: KIDNEY DONOR: Initially, 36 brown Norway (BN) rats were randomized for three procedures: 2 h of carbon dioxide (CO2) insufflation (8 mmHg), 2 h of helium insufflation (8 mmHg), and 2 h of gasless technique (0 mmHg). After this, a unilateral nephrectomy was performed in all the animals. EXPERIMENT 2: RECIPIENT: Subsequently, 36 donor BN rats were subjected to a similar insufflation protocol, but after nephrectomy, a syngeneic kidney transplantation (BN-BN) was performed. Urine and blood samples were collected on postoperative days 1, 3, 7, and 14 for determination of renal function. Subsequently, donor and recipient kidneys were removed for histomorphologic and immunohistochemical analysis. RESULTS: In both donors and recipients, no significant changes in serum creatinine, proteinuria, or glomular filtration were detected between the CO2, the helium, and the gasless control groups. In both experiments, histologic analysis of Kidney specimens did not show any deleterious effects from abdominal gas insufflation. Although kidney grafts exposed to CO2 showed significantly higher numbers of CD45+ leukocytes 3 days after transplantation, immunohistochemical analysis did not show significant differences in number of infiltrating cells (CD4, CD8, ED1, OX6, OX62) between the two insufflation groups and the gasless control subjects. CONCLUSIONS: Abdominal gas insufflation does not have an adverse effect on the renal function of the kidney donor 1 week after laparoscopic donor nephrectomy. No differences in renal function or histomorphology were detected between syngeneic kidney grafts exposed to pneumoperitoneum and gasless control subjects.

Animals↗
PubMed2001

Prevention of compensatory hyperhidrosis after thoracoscopic sympathectomy for hyperhidrosis.

BACKGROUND: Compensatory hyperhidrosis is a troublesome complication of thoracoscopic sympathectomy for hyperhidrosis. After extensive resection of the second through the fourth ganglion (T2-4), as well as after limited resection of the second ganglion (T2), the reported incidence of compensatory hyperhidrosis ranges as high as 50-97%. The purpose of this study was to determine whether the incidence of compensatory hyperhidrosis can be reduced by limiting the thoracoscopic sympathectomy to another level, the third ganglion. METHODS: We analyzed 28 thoracoscopic sympathectomies for palmar and/or axillary hyperhidrosis. In all patients, the sympathetic chain was transected cranially and caudally to the third ganglion (T3 dissection). Long-term follow-up was conducted by interviewing patients using standardized questionnaires. RESULTS: The surgery was effective in all patients. After a median follow-up of 3.5 years, compensatory hyperhidrosis was not recorded in any of the patients. There were no recurrences of hyperhidrosis. CONCLUSION: Limited thoracoscopic sympathectomy at the level of the third ganglion is effective and seems to prevent compensatory hyperhidrosis.

Adult↗
PubMed2001

[Laparoscopic myotomy in 14 patients with achalasia after unsuccessful pneumatic dilatations: effective and safe].

OBJECTIVE: Evaluation of laparoscopic myotomy with or without an anti-reflux (Dor) procedure in patients with achalasia. DESIGN: Retrospective. METHOD: Data were collected from patients who underwent a laparoscopic myotomy for achalasia, following repeated pneumatic dilations. In the period 1993-1998, seven patients were treated in the Dijkzigt location of the Erasmus University Hospital (Rotterdam, the Netherlands). In the period 1995-1999 seven patients were treated in the Free University Hospital (Amsterdam, the Netherlands) by means of a laparoscopic myotomy followed by Dor fundoplication. All of the patients received a check-up from their specialist according to a protocol and in 2000 they were requested to complete a questionnaire concerning how satisfied they were with the operation. RESULTS: In both groups the age ranged from 20 to 60 years (mean ages were 39 and 36 respectively) and the number of men and women was almost equal. There was no conversion. Average operation time was 1.5 hours for the group without fundoplication and 2.5 hours for the group with fundoplication. No perioperative or postoperative complications occurred. During the follow-up period (mean: 3.5 years; range: 1-7) one recurrence was encountered. In the group without fundoplication, reflux oesophagitis was observed in five of the patients. No reflux was encountered in the group with the added fundoplication. All of the patients preferred laparoscopic myotomy to pneumatic dilations. CONCLUSION: Laparoscopic myotomy was an effective and safe treatment for achalasia following repeated pneumatic dilations. The patients themselves were also satisfied. Without fundoplication, reflux oesophagitis was more prevalent.

Adult↗
PubMed2001

Technical considerations in laparoscopic liver surgery.

BACKGROUND: Laparoscopic solid organ surgery has gained growing acceptance, but this does not hold for laparoscopic surgery of the liver. Laparoscopic liver surgery mainly comprizes diagnostic procedures and treatment of liver cysts. However, we believe there is room for a laparoscopic approach to the liver in selected cases, with the benefits that may be expected from laparoscopic solid organ surgery. METHODS: Between 1993 and 2000, 10 patients with various lesions of the liver underwent laparoscopic surgery. Indications consisted of cystic disease (n = 2), hemangioma (n = 2), focal nodular hyperplasia (n = 2), liver abcess (n = 1), and liver metastasis (n = 3). Laparoscopic treatment varied from fenestration (n = 3) to wedge resections (n = 5), and formal left lateral hepatectomy (n = 2). RESULTS: The mean patient age was 54 years (range, 34-71 years). The mean operative time, including laparoscopic ultrasonography, measured 180 min (range, 80-240 min). Peroperative blood loss ranged from 200 to 450 ml. There was no mortality. In two patients, conversion to laparotomy was necessary. There were no postoperative complications. The mean hospital stay was 6 days (range, 4-11 days). CONCLUSION: Laparoscopic treatment should be considered in selected patients with benign and malignant lesions in the left lobe or frontal segments of the liver.

Adult↗
PubMed2001

The European Association for Endoscopic Surgery clinical practice guideline on the pneumoperitoneum for laparoscopic surgery.

BACKGROUND: The pneumoperitoneum is the crucial element in laparoscopic surgery. Different clinical problems are associated with this procedure, which has led to various modifications of the technique. The aim of this guideline is to define the scientifically proven standards of the pneumoperitoneum. METHODS: Based on systematic literature searches (Medline, Embase, and Cochrane), an expert panel consensually formulated clinical recommendations, which were graded according to the strength of available literature evidence. RECOMMENDATIONS: Preoperatively, all patients should be assessed for the presence of cardiac, pulmonary, hepatic, renal, or vascular comorbidity. Presupposing appropriate perioperative measures and surgical technique, there is no reason to contraindicate pneumoperitoneum in patients with peritonitis or intraabdominal malignancy. During laparoscopy, monitoring of end tidal CO2 concentration is mandatory. The available data on closed- (Veress needle) and open-access techniques do not allow us to principally favor the use of either technique. Using 2 to 5-mm instead of 5 to 10-mm trocars improves cosmetic result and postoperative pain marginally. It is recommended to use the lowest intraabdominal pressure allowing adequate exposure of the operative field, rather than using a routine pressure. In patients with limited cardiac, pulmonary, or renal function, abdominal wall lifting combined with low-pressure pneumoperitoneum might be an alternative. Abdominal wall lifting devices have no clinically relevant advantages compared to low-pressure (5-7 mmHg) pneumoperitoneum. In patients with cardiopulmonary diseases, intra- and postoperative arterial blood gas monitoring is recommended. The clinical benefits of warmed, humidified insufflation gas are minor and contradictory. Intraoperative sequential intermittent pneumatic compression of the lower extremities is recommended for all prolonged laparoscopic procedures. For the prevention of postoperative pain a wide range of treatment options exists. Although all these options seem to reduce pain, the data currently do not justify a general recommendation.

Contraindications↗