[A method for individualising the risk of a negative lymph node classification error in cancer of the colon].

Introduction: In cancer of the colon, the number of lymph nodes that should be analysed before a patient is classified as free of lymph node involvement has been widely discussed. A mathematical model is proposed which is based on the Bayes Theorem for calculating the probability of error (PE) similar to that normally used to evaluate a diagnostic test, but adapted to a quantitative variable, the lymph node count.

Methods: The clinical histories of 480 patients routinely operated on in attempt to cure cancer of the colon were reviewed.

[Recommendations for the clinical evaluation of results in the biomedical literature].

The assessment and interpretation of the results of a clinical study are a real challenge for the clinicians. In this paper we establish a general basis for a critical and reserved assessment of these, from the fundamental aspects of the design and statistics, as well as the application of the results to our own patients according to risk and benefit criteria. Main errors and the traps that should be avoided are emphasised.

Treatment of morbid obesity and hiatal paraesophageal hernia by laparoscopic Roux-en-Y gastric bypass.

Obesity has been proven to be a significant independent risk factor for hiatal hernia. In morbidly obese patients, the usual techniques to improve gastroesophageal reflux after hiatal hernia repair could have poorer outcomes than in the general population. Laparoscopic Roux-en-Y gastric bypass (LRYGBP) has been demonstrated to be an effective procedure in controlling symptoms and complications of gastroesophageal reflux in these patients.

[Brucella spp orchiepididymitis].

Objective: To report a brucellar orchiepididymitis case and to review the diagnosis and treatment of this pathology.

Method: We present the case of a 62 year old man presenting with fever, testicular pain and constitutional syndrome. The diagnosis was made after ultrasound, blood cultures and anamnesis.

[Is there a minimum number of lymph nodes that should be examined after surgical resection of colorectal cancer?].

Metastasis to regional lymph nodes, after distant metastasis, is the most important prognostic factor of colorectal carcinomas. It is also of primary importance in decisions related to the administration of adjuvant treatments. Most scientific associations recommend the examination of at least 12 lymph nodes for the reliable determination of the absence of nodal metastases.

[Confidence intervals: why use them?].

We analyze the reasons why the use of confidence intervals is highly advisable. Among these reasons, confidence intervals provide an approach to knowledge of the real importance of a result, independently of statistical significance, as well as equivalence assessment between two variables.