Jaap Bonjer

Publications (6)22.12 Total impact

• Article: Bowel obstruction after laparoscopic and open colon resection for cancer: results of 5 years of follow-up in a randomized trial.

  Johnna Schölin, Mark Buunen, Wim Hop, Jaap Bonjer, Bo Anderberg, Miguel Cuesta, Salvadora Delgado, Ainitze Ibarzabal, Marie-Louise Ivarsson, Martin Janson, Antonio Lacy, Johan Lange, Lars Påhlman, Stefan Skullman, Eva Haglind
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  ABSTRACT: Postoperative bowel obstruction caused by intra-abdominal adhesions occurs after all types of abdominal surgery. It has been suggested that the laparoscopic technique should reduce the risk for adhesion formation and thus for postoperative bowel obstruction. This study was designed to compare the incidence of bowel obstruction in a randomized trial where laparoscopic and open resection for colon cancer was compared. A retrospective analysis was performed, collecting data of episodes of bowel obstruction with or without surgery. Only episodes treated in the hospital where the index surgery took place were included. Data for 786 patients were collected for the 5-year period after cancer surgery. Baseline characteristics for the evaluated laparoscopic (n = 383) and open (n = 403) groups were comparable. The cumulative obstruction percentages at 5 years for the open and laparoscopic groups were 6.5 and 5.1% respectively and did not significantly differ from each other. Tumor stage seemed to influence the risk for bowel obstruction: 2.8% in stage I, 6.6% in stage II, and 7% in stage III, but the differences were not significant. This analysis does not support the hypothesis that laparoscopy leads to fewer episodes of bowel obstruction compared with open surgery.
  Surgical Endoscopy 06/2011; 25(12):3755-60. · 4.01 Impact Factor
• Article: Is right laparoscopic donor nephrectomy right?

  Mark Sawatzky, Abdulmalik Altaf, James Ellsmere, Dennis Klassen, Mark Walsh, Michele Molinari, Björn Nashan, Jaap Bonjer
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  ABSTRACT: Laparoscopic donor nephrectomy has become the standard of care in many renal transplant centers. Many centers are reluctant to perform right laparoscopic donor nephrectomies, primarily due to concerns about transplanting a kidney with a short renal vein. A retrospective review of 26 right and 24 left consecutive donor nephrectomies and their recipients was performed. Patient demographics, preoperative, perioperative, and postoperative data were recorded and compared. Patient demographics were similar between groups. Multiple vessels were encountered more frequently on the right side (10 vs. 3, p = 0.04) and the donated kidney had lesser preoperative function in the right group as determined by nuclear medicine imaging (46.5% vs. 49.4%, p < 0.001). Donor operating times were less in the right group (198 vs. 226 min, p = 0.016). There was no difference in implantation difficulty as demonstrated by similar operative and warm ischemia times. Complication rates were similar between both groups of donors and recipients. Right laparoscopic donor nephrectomy requires less operating time than, and is associated with similar outcomes for donors and recipients as, left laparoscopic donor nephrectomy. Right laparoscopic donor nephrectomy may be preferable in general and should be considered when multiple renal vessels are present on the left side and/or when preoperative function of the left kidney is greater than the right.
  Surgical Endoscopy 09/2008; 23(6):1321-5. · 4.01 Impact Factor
• Article: Long-term outcome of laparoscopic surgery for colorectal cancer: a cochrane systematic review of randomised controlled trials.

  Esther Kuhry, Wolfgang Schwenk, Robin Gaupset, Ulla Romild, Jaap Bonjer
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  ABSTRACT: The aim of this systematic review is to evaluate long-term outcome of laparoscopically assisted versus open surgery for non-metastasised colorectal cancer. Cochrane library, EMBASE, Pub med and CancerLit were searched for published and unpublished randomised controlled trials. RevMan 4.2 was used for statistical analysis. Twelve trials (3346 patients) reported long-term outcome and were included in the current analyses. No significant differences were found between laparoscopic and open surgery in the occurrence of incisional hernias or the number of reoperations for adhesions (p=0.32 and 0.30, respectively). Port-site metastases and wound recurrences were rare and no differences in occurrence after laparoscopic and open surgery were observed (p=0.16). Cancer-related mortality at maximum follow-up was similar after laparoscopic and open surgery (p=0.15 and 0.16 for colon and rectal cancer, respectively). No significant difference in tumour recurrence after laparoscopic and open surgery for colon cancer was observed (3 RCTs, hazard ratio for tumour recurrence in the laparoscopic group 0.86; 95% CI 0.70-1.08). In colon cancer patients, no significant differences in overall mortality were found (2 RCTs, hazard ratio for overall mortality after laparoscopic surgery 0.86; 95% CI 0.86-1.07). Laparoscopic resection of carcinoma of the colon is associated with a long-term outcome that is similar to that after open colectomy. Laparoscopic surgery for cancer of the upper rectum is feasible, but more randomised trials need to be conducted to assess long-term outcome.
  Cancer Treatment Reviews 06/2008; 34(6):498-504. · 6.05 Impact Factor
• Article: Novel criteria for parathyroid hormone levels in parathyroid hormone-guided parathyroid surgery.

  Robert de Vos tot Nederveen Cappel, Nicole Bouvy, Wouter de Herder, Yolanda de Rijke, Hans van Toor, Jaap Bonjer
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  ABSTRACT: Novel criteria for decrease of perioperative parathyroid hormone measurement may improve the accuracy of perioperative quick parathyroid hormone (qPTH)-guided parathyroidectomy. To assess overall cure rate based on conventional criteria (50% decline of qPTH). Perioperative qPTH levels were evaluated to determine novel criteria for successful parathyroid surgery. Analysis of perioperative qPTH measurement findings of all consecutive patients undergoing parathyroidectomy for hyperparathyroidism (72 with primary hyperparathyroidism and 28 with secondary or tertiary hyperparathyroidism or multiple endocrine neoplasia I/IIa disease). Measurement of qPTH (based solely on the criterion of greater than 50% decline of parathyroid hormone) in 72 patients with primary hyperparathyroidism (77 procedures) showed true-positive results in 69, false-positive results in 4, and true-negative results in 4 procedures. In our series, false-positive and true-negative results were associated with high postexcision levels. However, when qPTH declines of greater than 70% and 80% were used in cases of postexcision qPTH levels of 100 to 200 ng/L and greater than 200 ng/L, respectively, no false-positive results were observed. Through adherence to these novel criteria, reexploration of the neck could have been prevented in 29% of patients with primary hyperparathyroidism due to multiple gland disease. These novel criteria demand future evaluation to establish their value.
  Archives of pathology & laboratory medicine 01/2008; 131(12):1800-4. · 2.58 Impact Factor
• Article: Riolan's arch: confusing, misnomer, and obsolete. A literature survey of the connection(s) between the superior and inferior mesenteric arteries.

  Johan F Lange, Niels Komen, Germaine Akkerman, Erik Nout, Herman Horstmanshoff, Frans Schlesinger, Jaap Bonjer, Gerrit-Jan Kleinrensink
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  ABSTRACT: There are 2 interpretations of Riolan's arch: (1) Riolan's arch is identical to a central part of the marginal artery (MA), connecting the superior (SMA) and the inferior mesenteric (IMA) arteries; and (2) Riolan's arch represents a rare artery, connecting the SMA and the IMA. The current review aims to emphasize the clinical importance of the colon's vasculature and to show the feasibility of abolishing the terms "Riolan's arch" and "meandering mesenteric artery." A literature survey was performed. It appears that no distinct identity can be ascribed to Riolan's arch and that the "meandering mesenteric artery" represents an angiographically hypertrophied MA and/or the ascending branch of the left colic artery. However, a rare, centrally located, communicating artery has been described. Generally, the MA is sufficient for left colic circulation after ligation of the IMA, but at the splenic flexure, patency of the ascending branch of the left colic artery can be primordial. As connections between the SMA and the IMA can be adequately described using structures mentioned in Terminologica Anatomica, the terms "Riolan's arch" and "meandering mesenteric artery" should be abolished.
  American journal of surgery 07/2007; 193(6):742-8. · 2.36 Impact Factor
• Article: Protrusion of prosthetic meshes in repair of inguinal hernias.

  Erik Kes, Johan Lange, Jaap Bonjer, Rob Stoeckart, Paul Mulder, Chris Snijders, Gertjan Kleinrensink
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  ABSTRACT: Although techniques with prosthetic meshes have improved results of inguinal hernia repair, the problem of recurrence remains. In addition to patient- and surgeon-related causes, protrusion of prosthetic mesh through the hernia defect can be considered as a factor of recurrence. To simulate inguinal hernia, porcine tissue with standardized defects (3, 4, and 5 cm) was used. Nine different meshes (9 cm diameter) were positioned on the defects. In a pressure chamber the depth of protrusion through the defect was assessed. Both sides of each mesh were measured. Protrusion at a pressure representing Valsalva pressure was used for statistical analysis. Protrusion, including the incidence of collapse, increased with larger defect sizes. Significant protrusion differences were found between different meshes and occasionally between the 2 sides of the same mesh. The differences between the effects of the various meshes emphasize the importance of material characteristics when developing new surgical techniques. The 3 meshes showing least protrusion are considered especially suitable when repairing large defects or when preferring a small mesh when repairing inguinal hernias with a preperitoneal sublay approach.
  Surgery 03/2004; 135(2):163-70. · 3.10 Impact Factor