Does experience with laparoscopic colorectal surgery influence intraoperative outcomes?

Background  This study aimed to define the management and risk factors for intraoperative complications (IOC) and conversion in laparoscopic colorectal surgery, and to assess whether surgeon experience influences intraoperative outcomes. Methods  Consecutive patients undergoing laparoscopic colorectal procedures from 1991 to 2005 were analyzed from a longitudinal prospectively collected database. All patients referred to the four surgeons involved in this study were offered a minimally invasive approach. Patient characteristics, perioperative variables, and surgeon experience data were analyzed and compared. Results  A total of 991 consecutive laparoscopic colorectal procedures were studied. The majority of operations were performed for malignant disease (n = 526, 53%), and most frequently consisted of segmental colonic resections (n = 718, 72%). A total of 85 patients (8.6%) had an IOC. Patients experiencing an IOC had a significantly higher median body weight (75 versus 68 kg, p = 0.0047) and had a higher proportion of previous abdominal surgery (31% versus 20%, p = 0.029). Only 39% of patients suffering an IOC required conversion to open surgery. A total of 126 (13%) cases were converted to open surgery. On multivariable analysis, previous abdominal surgery [odds ratio (OR) 3.40, 95% confidence interval (CI) 1.39–8.35, p = 0.0076] was independently associated with having an IOC and a conversion to open within the same procedure. With increasing experience, individual surgeons were found to operate on heavier patients (p = 0.025), and on patients who had a higher rate of previous intra-abdominal surgery (p < 0.0001). Despite these risk factors, the early and late experience demonstrated no significant difference in terms of IOCs (p = 0.54) and conversion to open surgery (p = 0.40). Conclusions  The majority of IOCs can be managed laparoscopically. With increasing experience surgeons can perform laparoscopic colorectal surgery on a patient population with a greater proportion of previous abdominal surgery and a higher mean body weight without adversely affecting their rates of intraoperative complications or conversion. Oral presentation at the Scientific Session of the Society of American Gastrointestinal and Endoscopic Surgeons, April 12th, 2008, Philadelphia, PA.     

Chondroid cystic malformation of the lung with trisomy 8 mosaicism: a new cystic lung malformation

Neonatal cystic disorders of the lungs are a heterogeneous malformative group including giant lobar hyperinflation, congenital pulmonary airway malformations, intralobar pulmonary sequestration, and bronchogenic cyst. Here, we describe a giant cystic pulmonary malformation in a 5-year-old girl, morphologically characterized by a highly disorganized proliferation of numerous cartilage islands, abundant mesenchymal tissue with abundant adipose differentiation, and epithelium-lined cysts. Cytogenetic analysis revealed an isolated trisomy 8, as the sole karyotype anomaly, a finding further confirmed by a whole-genome single nucleotide polymorphism array genotyping. The trisomy 8 was observed by fluorescent in situ hybridization within the malformation, and also in adjacent pulmonary parenchyma. A search of the literature revealed only 2 cases having similarities with the present case, but bearing different names. We believe that this lesion differs from congenital pulmonary airway malformations and from adult-type pulmonary hamartomas. We propose for this malformative mass the name "chondroid cystic malformation of the lung."     

Relation of the "hypertriglyceridemic waist" phenotype to earlier manifestations of coronary artery disease in patients with glucose intolerance and type 2 diabetes mellitus

This study tested the hypothesis that the "hypertriglyceridemic waist" phenotype (waist girth >90 cm [35.4 inches] in men and >85 cm [33.5 inches] in women, along with a plasma triglyceride concentration of >or=2.0 mmol/L [177 mg/dl]) as a covariate of metabolic syndrome features (hyperinsulinemia, hyperapolipoprotein B, and small low-density lipoprotein particles), is predictive of premature coronary artery disease (CAD) among patients with glucose intolerance or type 2 diabetes. Glucose intolerance and type 2 diabetes were assessed after an oral glucose tolerance test among 1,190 men and women using the American Diabetes Association criteria. Glycemic control was evaluated using hemoglobin A1c levels. CAD was considered present on the basis of a clinical history of retrosternal pains on exertion, electrophysiologically and clinically documented myocardial infarction, or angiographic evidence of coronary lesions. More than 53% of men (n = 103) with a waist circumference >or=90 cm (35.4 inches) and nearly 80% of women (n = 122) with a waist circumference >or=85 cm (33.5 in.) with triglyceride levels >or=2 mmol/L (177 mg/dl) were diagnosed with glucose intolerance or type 2 diabetes. Survival models revealed that those with glucose intolerance or type 2 diabetes with the "hypertriglyceridemic waist" phenotype experienced their first CAD symptoms 5 years earlier than those without this phenotype. This elevated and earlier risk of CAD was statistically significant (hazard ratio 2.0, 95% confidence interval 1.2 to 3.7, p = 0.02). In conclusion, the "hypertriglyceridemic waist" phenotype, an inexpensive and simple tool identifying subjects with metabolic syndrome features, is a significant marker of CAD manifestations occurring at an earlier age in those with glucose intolerance or type 2 diabetes.     

Vascular and cellular stress in inflammatory bowel disease: revisiting the role of homocysteine

Moderate hyperhomocysteinemia is a complex trait commonly associated with inflammatory bowel disease (IBD). Nutritional deficiencies and genetic determinants have been identified as risk factors for moderate hyperhomocysteinemia, such as folate and vitamin B(12) deprivation and polymorphisms in the 5,10 methylenetetrahydrofolate reductase (MTHFR) encoding gene, respectively. Homocysteine has a crucial role in cellular stress, epigenetic events, inflammatory processes, and host-microbial interactions. Hyperhomocysteinemia might therefore influence the clinical history of IBD, including disease severity, susceptibility to particular enteric infections, and the risk for the development of colorectal cancer. In contrast, homocysteine metabolism does not seem to contribute to the greater risk of thrombosis in IBD subjects. Herein, we review the evidence linking homocysteine metabolism to the pathophysiology of IBD. Furthermore, we discuss the relevance of screening and treating folate and vitamin B(12) deficiencies in IBD subjects. Given the peculiar frequency of such deficiencies in IBD, normalizing vitamin levels should be an integral part of the management of these patients, especially those with active disease, history of intestinal resection, and/or treated with methotrexate.     

Management of metastatic prostate cancer: the crucial role of geriatric assessment

Prostate cancer predominantly affects older men, with a median age at diagnosis of 68 years. Due to the increased life expectancy, management of prostate cancer in senior adults (aged >70 years) represents a major public health problem. This patient population may not receive optimal therapy for their disease, if decisions are made based on their chronological age alone. More so than age alone, health status is a major factor affecting individual life expectancy. Comorbidity is the key predictor of health status and should weigh more heavily on the treatment decision than age alone. Other important parameters to consider in senior adults are the degree of dependence in activities of daily living, the nutritional status and the presence or not of a geriatric syndrome. Although clinical trials are rarely designed specifically for senior adults, evidence suggests that healthy senior adults have similar treatment outcomes to their younger counterparts. The urological approach in senior adults with advanced prostate cancer should be fundamentally the same as in younger patients. In hormone-sensitive metastatic prostate cancer, androgen deprivation represents the first-line treatment. In senior adults, care should be given to the increased risk of metabolic syndrome, cardiovascular mortality and bone fracture. In hormone-refractory metastatic prostate cancer, chemotherapy with docetaxel (75 mg/m(2) every 3 weeks) plus low-dose prednisone is the standard and shows the same efficacy in healthy senior adults as in younger patients. The tolerance of docetaxel (3-weekly schedule) has not been specifically studied in vulnerable and frail senior adults. The place of weekly docetaxel in this setting should be further evaluated. Palliative treatments (palliative surgery, radiopharmaceutics, radiotherapy, medical treatments for pain and symptoms, pharmacological palliative therapies) should also be integrated in the global management of these patients. In conclusion, treatment decisions in senior adults should be adapted to health status. Healthy senior adults should be treated the same as younger patients. The development of guidelines for the management of localized and advanced prostate cancer in senior adults is underway.     

Patient mood and neuropsychological outcome after laparoscopic and conventional colectomy

The study was designed to compare patients after laparoscopic and conventional colectomy with regard to early postoperative mood, cognitive function, and neurocognitive variables S100beta and neuron-specific enolase (NSE). Forty-five laparoscopic and 25 open colectomies were enrolled into the prospective study. Outcome measurements were positive and negative postoperative mood (BSKE), neuropsychological tests (Trail-Making Test; word reproduction; Stroop Test), and serum biochemical parameters (S100beta; NSE). Following laparoscopic procedure, patients described significantly better positive mood (P< .05), tended to require less time in the Trail-Making Test and Stroop Test, and had lower postoperative serum concentrations of S100beta compared to conventional colectomy patients (P< .01). The current results revealed several group differences, which, in their entirety, seem to represent a more beneficial outcome after laparoscopic colonic surgery.     

Nocodazole-induced changes in microtubule dynamics impair the morphology and directionality of migrating medial ganglionic eminence cells

We have shown previously that actomyosin contractility plays an important role in controlling nuclear movements in future interneurons born in the medial ganglionic eminence (MGE) [Bellion et al.: J Neurosci 2005;25:5691-5699]. Because microtubules are known to control the structural and motile properties of migrating neurons, we asked whether alterations in the dynamic instability of microtubules would impair MGE cell migration. Migration was analyzed in flat cocultures in which green-fluorescent-protein-expressing MGE cells migrate on cortical cells from their explant of origin. A low (100 nM) concentration of nocodazole shortened the leading process of MGE cells that nevertheless continued to migrate at the same rate but frequently changed their direction of migration relative to control cells. MGE cells treated with a higher (1 muM) concentration of nocodazole that strongly destabilized microtubules took on multipolar morphology. They extended thin and labile processes. MGE cells no longer exhibited directional migration and migration velocity slowed 2-fold. These results suggest that microtubule stability is crucial for maintaining polarity and controlling the directional migration of MGE cells, whereas additional mechanisms are required to control cell motility.     

Computer-aided optimal designs for improving neural network generalization

In this article we propose a new insight into the field of feed-forward neural network modeling. We considered the framework of the nonlinear regression models to construct computer-aided D-optimal designs for this class of neural models. These designs can be seen as a particular case of active learning. Classical algorithms are used to construct local approximate and local exact D-optimal designs. We observed that the so-called generalization of a neural network (the equivalent term, "predictive ability", is more familiar to statisticians) is improved when the D-efficiency of the chosen "learning set design" increases. We thus showed that the D-efficiency criterion can be the basis for a better strategy for the neural network learning phase than the standard uniform random strategy encountered in this field. Our proposition is based on two possible strategies: a One-Step Strategy or a Full Sequential Strategy. Intensive Monte Carlo simulations with an academic example show that the D-optimal "learning set design" strategies proposed lead to a substantial improvement in the use of neural network models.