Michel Meurisse

Pathophysiology and prevention of postoperative peritoneal adhesions

Peritoneal adhesions represent an important clinical challenge in gastrointestinal surgery. Peritoneal adhesions are a consequence of peritoneal irritation by infection or surgical trauma, and may be considered as the pathological part of healing following any peritoneal injury, particularly due to abdominal surgery. The balance between fibrin deposition and degradation is critical in determining normal peritoneal healing or adhesion formation. Postoperative peritoneal adhesions are a major cause of morbidity resulting in multiple complications, many of which may manifest several years after the initial surgical procedure. In addition to acute small bowel obstruction, peritoneal adhesions may cause pelvic or abdominal pain, and infertility. In this paper, the authors reviewed the epidemiology, pathogenesis and various prevention strategies of adhesion formation, using Medline and PubMed search. Several preventive agents against postoperative peritoneal adhesions have been investigated. Their role aims in activating fibrinolysis, hampering coagulation, diminishing the inflammatory response, inhibiting collagen synthesis or creating a barrier between adjacent wound surfaces. Their results are encouraging but most of them are contradictory and achieved mostly in animal model. Until additional findings from future clinical researches, only a meticulous surgery can be recommended to reduce unnecessary morbidity and mortality rates from these untoward effects of surgery. In the current state of knowledge, pre-clinical or clinical studies are still necessary to evaluate the effectiveness of the several proposed prevention strategies of postoperative peritoneal adhesions.

Breast cancer and serum organochlorine residues

Background: Controversy still exists about the breast carcinogenic properties in humans of environmental xenoestrogens (organochlorines), justifying new investigations. Aims: To compare the blood levels of total dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB) in samples collected at the time of breast cancer discovery, in order to avoid the potential consequences of body weight change (after chemotherapy or radiotherapy) on the pesticide residue levels. Methods: Blood levels of HCB and total DDT (we calculated total DDT concentrations by adding all DDT and DDE isomers) were compared in 159 women with breast cancer and 250 presumably healthy controls. Risk of breast cancer associated with organochlorine concentration was evaluated. Results: Mean levels of total DDT and HCB were significantly higher for breast cancer patients than for controls. No differences in serum levels of total DDT or HCB were found between oestrogen receptor positive and oestrogen receptor negative patients with breast cancer. Conclusions: These results add to the growing evidence that certain persistent pollutants may occur in higher concentrations in blood samples from breast cancer patients than controls.

Mutation analysis of the MEN1 gene in Belgian patients with multiple endocrine neoplasia type 1 and related diseases

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by tumors in parathyroids, enteropancreatic endocrine tissues, anterior pituitary, and other tissues. The gene for MEN1 has recently been cloned and shown to code for a 610‐amino acid protein of enigmatic function which probably acts as a tumor suppressor. Several mutations causing the MEN1 phenotype have been recently identified. In order to determine the spectrum of MEN1 gene mutations in a sample of 25 Belgian patients, we have systematically screened the 10 exons and adjacent sequences of the MEN1 gene by means of an automatic sequencing protocol. Twelve different mutations were identified including nonsense, frameshift, splicing, and missense mutations. Two of these mutations (D172Y and 357del4) occurred more than once. A missense mutation was also found in a kindred with familial hyperparathyroidism. We observed no significant correlation between the nature or position of mutation and the clinical status. We have also detected 6 intragenic polymorphisms and DNA sequence variants and have analyzed their frequencies in our population. Hum Mutat 13:54–60, 1999.

Evidence for free radical formation during human kidney transplantation

Fourteen patients undergoing kidney transplantation were studied for evidence of the production of free radicals as assessed by the measurement of vitamin E (an index of lipid peroxidation) and of myeloperoxidase (a marker of neutrophil activation) in the systemic blood. Early (2 min) and late revascularization (30 min) of the kidney were respectively associated with a significant decrease of 35.5 and 40% of the initial level of plasma vitamin E. This consumption paralleled to the decrease of the vitamin E/total lipids ratio, a better indicator of vitamin E status. Heparin administration preceding renal artery clamping resulted in a twofold significant increase of baseline plasma myeloperoxidase (MPO) level (523 +/- 214 ng/ml). At kidney reperfusion, MPO concentration rose again and reached a maximum value of 1,653 +/- 882 ng/ml, indicating the presence of considerable neutrophil activation. A return to the baseline value was observed after 30 min of reperfusion. A short discussion about the possible origin of this MPO increase is given. Taken together, these data strongly suggest that free radical production, leading to lipid peroxidation phenomena, can occur within the early phase of kidney revascularization. Preliminary data using electron spin resonance with the spin-trapping technique strengthen this hypothesis.

Bilateral neck exploration under hypnosedation : A new standard of care in primary hyperparathyroidism?

OBJECTIVE The authors review their experience with initial bilateral neck exploration under local anesthesia and hypnosedation for primary hyperparathyroidism. Efficacy, safety, and cost effectiveness of this new approach are examined. BACKGROUND Standard bilateral parathyroid exploration under general anesthesia is associated with significant risk, especially in an elderly population. Image-guided unilateral approaches, although theoretically less invasive, expose patients to the potential risk of missing multiple adenomas or asymmetric hyperplasia. Initial bilateral neck exploration under hypnosedation may maximize the strengths of both approaches while minimizing their weaknesses. METHODS In a consecutive series of 121 initial cervicotomies for primary hyperparathyroidism performed between 1995 and 1997, 31 patients were selected on the basis of their own request to undergo a conventional bilateral neck exploration under local anesthesia and hypnosedation. Neither preoperative testing of hypnotic susceptibility nor expensive localization studies were done. A hypnotic state (immobility, subjective well-being, and increased pain thresholds) was induced within 10 minutes; restoration of a fully conscious state was obtained within several seconds. Patient comfort and quiet surgical conditions were ensured by local anesthesia of the collar incision and minimal intravenous sedation titrated throughout surgery. Both peri- and postoperative records were examined to assess the safety and efficacy of this new approach. RESULTS No conversion to general anesthesia was needed. No complications were observed. All the patients were cured with a mean follow-up of 18 +/- 12 months. Mean operating time was <1 hour. Four glands were identified in 84% of cases, three glands in 9.7%. Adenomas were found in 26 cases; among these, 6 were ectopic. Hyperplasia, requiring subtotal parathyroidectomy and transcervical thymectomy, was found in five cases (16.1%), all of which had gone undetected by localization studies when requested by the referring physicians. Concomitant thyroid lobectomy was performed in four cases. Patient comfort and recovery and surgical conditions were evaluated on visual analog scales as excellent. Postoperative analgesic consumption was minimal. Mean length of hospital stay was 1.5 +/- 0.5 days. CONCLUSIONS Initial bilateral neck exploration for primary hyperparathyroidism can be performed safely, efficiently, and cost-effectively under hypnosedation, which may therefore be proposed as a new standard of care.

Multicentric experience of the Belgian Group for Endoscopic Surgery (BGES) with endoscopic adrenalectomy

AbstractBackground: Adrenalectomy is not a frequent operation. Therefore the newly developed laparoscopic approach is sporadically performed by surgeons dealing with endocrine disorders. Methods: Some 54 videoendoscopic adrenalectomies performed on 52 patients by five surgical teams between October 1993 and December 1996 were prospectively evaluated. Results: Indications for endoscopic adrenalectomy were pheochromocytoma (n= 17), primary hyperaldosteronism (n= 15), Cushings adenoma or disease (n= 7), nonsecreting adenoma (n= 7), single metastasis from adenocarcinoma (n= 2), adenoma with dehydroepiandrostenedione (DHEAS) hypersecretion (n= 3), and ACTH-secreting metastases from a thymoma (n= 1). Of the 54 adrenalectomies performed, 31 were of the left gland, 19 of the right and two bilateral. Laparoscopic adrenalectomy was successful in 50 patients (96%). Median tumor size was 4 cm (range 1.5–12), median operation duration was 80 min (range 59–360), and median postoperative stay was 4 days (range 2–13). One patient required blood transfusion. Conclusions: Endoscopic adrenalectomy can safely be performed—even sporadically—by surgeons well versed in adrenalectomy techniques for endocrine disorders and trained in endoscopic surgery.

Surgical Management of Amiodarone-associated Thyrotoxicosis: Too Risky or Too Effective?

Abstract. Amiodarone-associated thyrotoxicosis, often clinically mild and resolutive after amiodarone discontinuation or under medical therapy, is sometimes drug unresponsive and not uncommonly follows a dramatic, even fatal course. Therefore, we considered a surgical solution in 15 severely amiodarone-associated thyrotoxic patients. Twelve men and three women (mean age 68 years, range 50–84 years) underwent radical thyroidectomy for clinical and biologically proved amiodarone-associated thyrotoxicosis. In six surgery was the first-line therapeutic option. In the other nine thyroidectomy seemed unavoidable considering the unresponsiveness to medical therapy and rapid deterioration of the patients’ clinical condition, with life-threatening cardiac failure in three. In every patient surgery was conducted without immediate or delayed complications. Total thyroidectomy proved uniformly, definitively, and rapidly effective in controlling thyrotoxicosis in all patients, with a spectacular reversal of cardiac failure in the three most critical cases. Surgery was beneficial to our 15 patients and undoubtedly life-saving in the three most worrying cases. These results suggest that thyroidectomy should be more liberally regarded as an interesting alternative to conventional, but unpredictably effective, medical therapies.

Fluorine-18-fluorodeoxyglucose positron emission tomography for preoperative parathyroid imaging in primary hyperparathyroidism

Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging was performed in seven consecutive patients with primary hyperparathyroidism to preoperatively locate parathyroid adenomas. Foci of FDG accumulation corresponding to abnormal parathyroid tissue were observed in two out of nine surgically excised parathyroid adenomas. It was concluded that FDG PET imaging demonstrated a too low sensitivity for systematic preoperative detection and localization of parathyroid glands causing primary hyperparathyroidism.

Report of two cases of gastric cancer after bariatric surgery: lymphoma of the bypassed stomach after Roux-en-Y gastric bypass and gastrointestinal stromal tumor (GIST) after vertical banded gastroplasty.

We report two new cases of gastric cancer diagnosed after a bariatric operation. The first case is a 66-year-old male who 3 years after gastric bypass suffered from a perforation of the fundus that was found to be secondary to a diffuse large B-cell lymphoma of the distal stomach. The second case is a 47-year-old woman who presented 12 years after a vertical banded gastroplasty with a gastric pouch outlet obstruction caused by a gastrointestinal stromal tumor (GIST). Based on the few reports of cancer in the literature, analysis of these cases suggests that the main risk of gastric cancer after bariatric surgery comes from the delayed diagnosis of malignancy.

Laparoscopic removal of pheochromocytoma Why? When? and Who? (Reflections on one case report)

Until now, the need for wide exposure and nonmanipulative dissection of pheochromocytoma has dictated the use of a large intraperitoneal transabdominal approach, which unfortunately results in a significant incidence of morbidity. A unilateral retroperitoneal approach guided by the refinements of new imaging techniques is less invasive but is associated with a small risk of incomplete cure. In one case report, we tested the hypothesis that laparoscopic surgery could combine the beneficial effects of both operative strategies without their respective side effects. We concluded that a laparoscopic approach combined with exclusive intraoperative infusion of nicardipine, a calcium-channel blocker, can be used to surgically remove pheochromocytoma under stable hemodynamic conditions. This provides better exposure of the anatomical structures than open surgery and allows a visual exploration of the entire abdominal cavity to exclude tumor multicentricity or ectopic sites in the case of inconclusive preoperative imaging investigations. Moreover, conversion to open surgery is always possible if needed.