Showing papers by "Geerard L. Beets published in 2009"

A comparison between the treatment of low rectal cancer in Japan and the Netherlands, focusing on the patterns of local recurrence

Abstract: Purpose Differences exist between Japan and The Netherlands in the treatment of low rectal cancer. The purpose of this study is to analyze these, with focus on the patterns of local recurrence. Methods In The Netherlands, 755 patients were operated by total mesorectal excision (TME) for low rectal cancer, 379 received preoperative radiotherapy (RT+TME). Applying the same selection criteria resulted in 324 patients in the Japanese (NCCH) group, who received extended surgery consisting of lateral lymph node dissection and a wider abdominoperineal excision. The majority received no (neo) adjuvant therapy. Local recurrence images were examined by a radiologist and a surgeon. Results Five-year local recurrence rates were 6.9% for the Japanese NCCH group, 5.8% in the Dutch RT+TME group, and 12.1% in the Dutch TME group. Recurrence rate in the lateral pelvis is 2.2%, 0.8%, and 2.7% in the Japanese, RT+TME group, and TME group, respectively. The incidence of presacral recurrences was low in the NCCH group (0.6%), compared with 3.7% and 3.2% in the RT+TME and TME groups, respectively. Conclusions Both extended surgery and RT+TME result in good local control, as compared with TME alone. Preoperative radiotherapy can sterilize lateral extramesorectal tumor particles. A wider abdominoperineal resection probably results in less presacral local recurrence. Comparison of the results is difficult because of differences in patient groups.

Locally advanced rectal cancer: MR imaging for restaging after neoadjuvant radiation therapy with concomitant chemotherapy. Part I. Are we able to predict tumor confined to the rectal wall?

Abstract: Purpose: To retrospectively assess accuracy of magnetic resonance (MR) imaging after radiation therapy with concomitant chemotherapy for downsizing of the primary lesion to ypT0–2 tumor confined to rectal wall in locally advanced rectal cancer, with histopathologic findings as reference standard, and to evaluate additional value of volumetric analysis. Materials and Methods: The institutional review board approved the study and waived informed consent. Sixty-seven patients met criteria of the study. T2-weighted MR images obtained before and after radiation therapy with concomitant chemotherapy were assessed for tumor stage by expert abdominal radiologist, colorectal surgeon, and general radiologist. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated; tumor volume was measured (compared with Mann-Whitney U test). Findings were correlated with histopathologic findings. Results: Sixty-seven patients (38 men, 29 women; mean age, 63 years) who underwe...

Degradation of mesh coatings and intraperitoneal adhesion formation in an experimental model.

Abstract: Background: In laparoscopic ventral hernia repair a mesh is placed in direct contact with the viscera, often leading to substantial adhesions. In this experimental study the ability of different coated and uncoated meshes to attenuate adhesion formation was examined. Methods: Six commercially available meshes were placed intraperitoneally against a closed peritoneum in rats: Prolene® (polypropylene), Timesh® and Ultrapro® (polypropylene composites with titanium and polyglecaprone respectively), Proceed® and Parietex Composite® (polypropylene and polyester meshes coated with a layer of cellulose and collagen respectively) and C-Qur® (polypropylene mesh coated with a layer of omega-3 fatty acids). Adhesions and incorporation were evaluated macroscopically and microscopically after 7 and 30 days. Results: Parietex Composite® and C-Qur® significantly reduced adhesion formation at 7 days' follow-up compared with all other meshes. By 30 days, this effect had diminished as a significant increase in adhesions together with phagocytosis of the coating was seen for all meshes with layered coatings (Proceed®, Parietex Composite® and C-Qur®). Incorporation was insufficient for all meshes. Conclusion: The absorbable layers of Parietex Composite® and C-Qur® reduce adhesion formation to intraperitoneal mesh in the short term, but the effect diminishes and phagocytosis of absorbable coatings may contribute to adhesion formation. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Locally advanced rectal cancer: MR imaging for restaging after neoadjuvant radiation therapy with concomitant chemotherapy. Part II. What are the criteria to predict involved lymph nodes?

Abstract: Purpose: To prospectively determine diagnostic performance of predictive criteria for nodal restaging after radiation therapy with concomitant chemotherapy by using ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance (MR) imaging in patients with rectal cancer. Materials and Methods: After institutional review board approval and informed consent were obtained, 39 patients (24 men, 15 women; mean age, 64 years) with rectal cancer underwent USPIO-enhanced two-dimensional (2D) T2-weighted fast spin-echo, three-dimensional (3D) T1-weighted gradient-echo, and 3D T2*-weighted MR for restaging. Two observers evaluated nodes for border irregularity, short- and long-axis diameters, and estimated percentage of white region ( 50%) within the node (3D T2*-weighted images). Ratio of the measured surface area of the white region within the black node to the measured surface area of the total node (RatioA) was calculated. Signal intensity (SI) in gluteus muscle (SIGM) and in tot...

Long-term quality of life in patients with rectal cancer: association with severe postoperative complications and presence of a stoma.

Abstract: PURPOSE: The purpose of this study was to evaluate the impact of postoperative complications and the presence of a stoma on long-term quality of life in patients with rectal cancer. METHODS: Consecutive patients with an adenocarcinoma of the rectum who underwent surgery at Maastricht University Medical Center or VieCuri Medical Center between 2003 and 2005 were included in this study. Data on surgical treatment and complications were collected. Severe postoperative complications were classified according to a standardized complication severity score. Quality of life was assessed by use of the European Organization for Research and Treatment of Cancer core and colorectal cancer–specific quality-of-life questionnaires. RESULTS: One hundred seventy patients received a questionnaire, and 121 (71%) responded. Of the responders, 33 (27.3%) patients suffered from severe postoperative complications. The median follow-up was 36 months. In the univariate analysis, patients with severe postoperative complications had a lower score on physical functioning (73 vs. 85, P 0.031) and higher scores on pain (17 vs. 0, P 0.025) and fatigue (33 vs. 22, P 0.036). Stoma construction (n 51) was associated with a higher global health status (83 vs. 75, P 0.019), and these patients reported fewer gastrointestinal problems (P 0.001). CONCLUSION: Severe postoperative complications seem to be associated with several lower quality-of-life subscores over the long term. In contrast, a stoma is associated with improved global health status and leads to fewer gastrointestinal complaints. In patients prone to complications, it may be sensible to avoid creating a low anastomosis and to construct a permanent stoma immediately.

Polypropylene Meshes to Prevent Abdominal Herniation. Can Stable Coatings Prevent Adhesions in the Long Term

Abstract: Abdominal surgery is associated with a significant risk for incisional herniation. Hernia repair is routinely performed by implantation of synthetic meshes. Such meshes may cause serious adhesions between the implanted material and organs leading to intestinal obstruction or enterocutaneous fistulas. This study compares three knitted meshes for their capacity to prevent adhesion formation in an in vivo study. The meshes evaluated are polypropylene (Prolene®), polypropylene coated with oxygenated regenerated cellulose—in principle—a biodegradable biomaterial (Proceed®), and Prolene® coated with a nondegradable copolymer of the hydrophilic building block N-vinyl pyrrolidone (NVP) and the hydrophobic building block n-butylmethacrylate (BMA). The meshes were implanted in the abdomen of rats (follow-up 7 or 30 days). After 7 days, the formation of adhesions decreased in the order: Prolene® > NVP/BMA-coated Prolene® > Proceed®; after 30 days, this order changed into: Proceed® > Prolene® > NVP/BMA-coated Prolene®. Both at 7 and at 30 days, Proceed® was the only mesh surrounded by macrophage cells that contained foreign materials, presumably degradation products of the (biodegradable) surface coating. The data indicate that long-term protection of implanted meshes against excessive adhesions may be achieved through stable biocompatible hydrogel surface coatings.

Assessment of the steady-state pharmacokinetic interaction between etravirine administered as two different formulations and tenofovir disoproxil fumarate in healthy volunteers.

Abstract: Objective Two open-label, randomized, cross-over trials in healthy volunteers were conducted to investigate the pharmacokinetic interaction between etravirine and tenofovir disoproxil fumarate. Methods Etravirine was administered as either 800 mg twice a day (bid) (phase II formulation in Study 1) or 200 mg bid (phase III formulation in Study 2) for 8 days followed by a 12 h pharmacokinetic evaluation. After a minimum of 14 days washout, tenofovir disoproxil fumarate 300 mg once a day was administered for 16 days. Volunteers were randomized to receive co-administration of etravirine with tenofovir disoproxil fumarate on either days 1–8 or days 9–16 followed by a 12 h pharmacokinetic evaluation for etravirine on day 8 or 16, respectively. Plasma and urine tenofovir concentrations were determined on days 8 and 16 over 24 h. Results The least square mean (LSM) ratio [90% confidence interval (CI)] for the area under the plasma concentration–time curve from 0 to 12 h (AUC12 h) for etravirine co-administered with tenofovir disoproxil fumarate vs. etravirine alone was 0.69 (0.61–0.79) and 0.81 (0.75–0.88) in Studies 1 and 2, respectively. The LSM ratio (90% CI) for the effect of etravirine on tenofovir AUC24 h was 1.16 (1.09–1.23) in Study 1 and 1.15 (1.09–1.21) in Study 2. Conclusions These alterations are not considered clinically relevant for either drug and no dose adjustment is necessary when etravirine and tenofovir disoproxil fumarate are co-administered.

[Loss of renal function due to deep infiltrating endometriosis; a complicated consideration in women who wish to have children].

Abstract: Three nulliparous women, aged 39, 34 and 26 years, who were treated for fertility problems and who were affected by endometriosis, presented with ureteral obstruction caused by deep infiltrating endometriosis. The first two patients had complete unilateral loss of kidney function at the time of diagnosis. They chose to have fertility treatment first and both became pregnant. The third patient still had 24% renal function in the affected left kidney. She was treated by complete surgical resection of the endometriosis and reimplantation of the ureter. Ureteral obstruction is a rare, but serious, complication of deep infiltrating endometriosis. Timely recognition is important, since delay results in unnoticed loss of renal function. Clinical investigation for endometriosis of the posterior vaginal fornix is recommended for all patients with chronic abdominal pain, severe dysmenorrhoea or deep dyspareunia. On diagnosis of deep infiltrating endometriosis, further examination is necessary to detect possible ureteral obstruction and consequent hydronephrosis, which can be demonstrated by ultrasound. MRI is of value to map the extent of disease, which is usually multi-focal. Surgery to relieve ureteral obstruction and remove all endometriotic lesions is the treatment of choice if the kidney is still functional.