Laparoscopic adrenalectomy: lessons learned from an initial series of 100 patients.

BACKGROUND: Laparoscopic adrenalectomy is considered the gold standard for the surgical treatment of adrenal disorders in most centers. This study analyzes the authors' experience using the lateral intraperitoneal approach with the first 100 patients. In addition to analyzing the authors' experience, this article aims to contrast it with some published series as an internal quality control. METHODS: In a 10-year period, 138 laparoscopic adrenalectomies were performed for 100 patients. Demographics, surgical results, complications, and long-term outcomes were analyzed. RESULTS: The participants comprised 69 women and 31 men with a mean age of 37 years. The procedures included 24 right, 38 left, and 38 bilateral adrenalectomies. The indications for surgery were Cushing's disease for 33 patients, pheochromocytoma (4 bilateral) for 23 patients, Cushing's syndrome for 18 patients, Conn's syndrome for 16 patients, and incidentaloma for 10 patients. Five procedures were converted to open surgery. Two patients with pheochromocytoma required intraoperative blood transfusion. The mean operative time was 174 min for unilateral adrenalectomies and 302 min for the bilateral procedures. The mean hospital stay was 5 days. Surgical morbidity included an abdominal wall hematoma, a small pneumothorax, and intraabominal bleeding in one patient that required reexploration. There were three operative mortalities not related to the technique. The long-term results showed control of hypercortisolism in all the patients with Cushing's disease and 82% of the patients with pheochromocytoma. Most of the patients with Conn's syndrome (91.4%) became normotensive after surgery. CONCLUSIONS: Laparoscopic adrenalectomy is safe and effective. The complications are mild, and mortality is related more to the patient's condition than to the surgical technique.

The combination metformin/glyburide exerts its hypoglycemic effect mainly by increasing insulin secretion: a controlled, randomized, double-blind, crossover study.

The aim of the present study was to describe the mechanism by which the combination glyburide/metformin exerts its additive hypoglycemic effects. This is a double-blind, randomized and crossover clinical trial. Patients (n = 20) were included in a run-in period of 8 weeks in which an isocaloric diet was prescribed. If they did not achieve the treatment goals (n = 15), they received glyburide, metformin or combined treatment for 10 weeks each using three possible sequences. The dosage was adjusted to reach fasting plasma glucose (FPG) < 7.7 mmol/l. Treatment periods were separated by a 6-12 week washout period. At the beginning and the end of every treatment, insulin sensitivity and insulin secretion were measured by means of a minimal model and an oral glucose tolerance test. All treatment periods were completed by 12 cases. The glycemic goal was reached in 1 case during metformin, in 5 during glyburide and in 10 during the combination. The greatest reduction in HbA1c was achieved during the combination (HbA1c 11 +/- 1.6 vs 9.8 +/- 1.9 vs 9.0 +/- 2.1% for metformin, glyburide and the combination, p < 0.001). Increased insulin secretion was the explanation for the additive effects of the combination (percentual change in acute insulin response during the minimal model = 5.8 vs 51.5 vs 88.2% for metformin, glyburide and the combination, p < 0.05). No change in insulin sensitivity resulted from the treatments. In conclusion, the additive hypoglycemic effects of the combination glyburide/metformin was caused by increased insulin secretion.

High prevalence of low HDL cholesterol concentrations and mixed hyperlipidemia in a Mexican nationwide survey.

The prevalence of lipid abnormalities revealed in a survey done in 417 Mexican cities is described. Information was obtained on 15,607 subjects, aged 20 to 69 years. In this report, only samples obtained after a 9- to 12-h fast were included (2,256 cases: 953 men and 1,303 women). The population is representative of Mexican urban adults. Mean lipid concentrations were: cholesterol, 4.80 mmol/l; triglycerides, 2.39 mmol/l; HDL cholesterol, 1.00 mmol/l; and LDL cholesterol, 3.06 mmol/l. The most prevalent abnormality was HDL cholesterol below 0.9 mmol/l (46.2% for men and 28.7% for women). Hypertriglyceridemia (>2.26 mmol/l) was the second most prevalent abnormality (24.3%). Severe hypertriglyceridemia (>11.2 mmol/l) was observed in 0.42% of the population. Increased LDL cholesterol (> or =4.21 mmol/l) was observed in 11.2% of the sample. Half of the hypertriglyceridemic subjects had a mixed dyslipidemia or low HDL cholesterol. More than 50% of the low HDL cholesterol cases were not related to hypertriglyceridemia. Insulin resistance was found in 59% of them. In conclusion, the prevalence of hypoalphalipoproteinemia and other forms of dyslipidemia in Mexican adults is very high and it is among the highest previously reported worldwide.

[Limitations of the diagnostic criteria for type 2 diabetes and glucose intolerance]. / Limitaciones de los criterios de diagnóstico de la diabetes tipo 2 y la intolerancia a la glucosa.

Conflicting results have been published during the past three decades regarding the cut points for the diagnosis of diabetes and glucose intolerance. Two major consensus changed the diagnostic values; the last revision occurred in 1997. After the publication of the new criteria, the controversy grew. New evidence was published demonstrating that the new cut points were inappropriate. The purpose of this review paper is to summarize the currently available information useful to evaluate the sensibility and specificity of the diagnostic criteria and to discuss the difficulties to define properly the cut-points for the diagnosis of diabetes and glucose intolerance.

Laparoscopic versus open adrenalectomy in Cushing's syndrome and disease.

BACKGROUND: Adrenalectomy in Cushing's syndrome and disease involves particular risks and complications. The aim of the study was to compare the open posterior and the flank laparoscopic approaches in this group of patients. METHODS: Forty patients who underwent unilateral or bilateral adrenalectomy for hypercortisolism between 1991 and 1999 were studied. Patients were divided as follows: adenoma--5 laparoscopic and 6 open; hyperplasia--17 laparoscopic and 12 open. Demographics, surgical details, outcome, and complications were comparatively analyzed. RESULTS: Patients undergoing laparoscopic or open adrenalectomy were comparable in terms of age, sex distribution, body mass index, respiratory status, and anesthetic risk. Operative time was longer in the laparoscopic group. One patient in the laparoscopic group died of upper gastrointestinal tract bleeding on postoperative day 17. Two patients in the open group and one in the laparoscopic group experienced postoperative complications. Cure of the disease occurred in all patients. Mild abdominal wall pain developed in one patient in each group. No abdominal wall weakness was identified in either group. CONCLUSIONS: Cure rate and operative and long-term morbidity were similar for laparoscopic and open adrenalectomies in this series. However, it is important to emphasize that late complications in our patients who underwent the posterior open procedure were rather infrequent.

[Diagnosis of malignant and benign insulinoma. Experience of the National Institute of Nutrition]. / Diagnóstico de insulinomas malignos y benignos. Experiencia en el Instituto Nacional de la Nutrición.

INTRODUCTION: Insulinomas are uncommon tumors, their incidence is approximately one case for 1 million population per year. OBJECTIVE: To expose our experience in the diagnosis of these tumors at the Instituto Nacional de la Nutrición Salvador Zubirán. MATERIAL AND METHODS: All patients with histologic diagnosis of insulinoma were reviewed; the period was from 1959 to 1996. The methods used for diagnosis and localization as well as the clinical picture according to the benignity or malignity of the tumor were registered. RESULTS: Eighteen patients were included, four of them with malignant tumors. In two patients islet cell tumors occurred in association with MEN type I, one of them benign and the other malignant. The mean age of patients with benign tumor was 38.2 +/- 13.5 years, in those with malignant tumors it was 51.5 +/- 16.2 years. The median period between symptoms and diagnosis was 34.4 +/- 15 months for benign tumors and 6 +/- 1.1 months for those with malignant tumors (p = 0.02). Patients with increasing weight had benign tumors. The 24 hours fasting test was not done in patients with malignant tumors because of the severity of hypoglycemia. The insulin/glucose ratio in patients with a malignant tumor was 5.2 +/- 4.7, while in patients with a benign tumor it was 1.82 +/- 1.7. The imaging studies showed that three patients with malignant tumors had hepatic metastasis and one had lymph node metastasis. The low accuracy of localization by radiological methods is due to the size of the tumor (> 2 cm). CONCLUSIONS: Malignant insulinomas are more aggressive and the delay of diagnosis is shorter that in cases with benign tumors. Selective arteriography remains the best preoperative localization procedure.

Diseases and problems secondary to massive obesity.

Morbid obesity is a health hazard. It carries several health risks and decreases life expectancy. Individuals with morbid obesity may develop one or more complications. These are mainly cardiovascular, metabolic, respiratory, gastrointestinal, renal, genitourinary and gynaecological. Patients with morbid obesity also have a high surgical risk. This review analyses the most common complications of morbidly obese patients and their changes after surgically induced weight loss.

The apolipoprotein E4 allele is not associated with an abnormal lipid profile in a Native American population following its traditional lifestyle.

The apolipoprotein E4 allele is associated in industrialized countries with an elevated LDL cholesterol concentration and an increased cardiovascular risk. Our purpose in this study was to assess the influence of the genetic variation at the APOE gene locus on the lipid profile of a Native American rural population. We examined plasma lipid levels and the common apo E alleles in 142 healthy randomly selected adults living in their native communities in western Mexico. Their age was 38+/-17 years and the BMI 25.7+/-4.5 kg/m2. Plasma cholesterol, triglycerides, LDL C and HDL C were 165+/-29.6, 126+/-83, 98+/-26 and 42+/-12.7 mg/dl respectively. Ninety-one per cent of the subjects had Lp(a) concentrations below 20 mg/dl and 30% had levels lower than 2 mg/dl. The most common APOE genotype was E3/3 (63%), followed by E3/4 (30.1%). The prevalence of the E2 allele was very low (2.3%). No difference was observed in LDL C concentrations between the E3/E3 and E3/E4 subjects; however carriers of the E2/3 genotype had lower LDL C levels. Similar results were obtained for cholesterol and apo B levels. In summary, the increased LDL C levels associated with the E4 allele in previous studies were not observed in a population with non-westernized habits. Environmental factors, such as diet and lifestyle, could outweigh the hypercholesterolemic predisposition resulting from the presence of the apo E4 allele.

Lack of agreement between the World Health Organization Category of impaired glucose tolerance and the American Diabetes Association category of impaired fasting glucose.

OBJECTIVE: To study the concordance between the 1997 American Diabetes Association (ADA) impaired fasting glucose (IFG) category with the World Health Organization (WHO) impaired glucose tolerance (IGT) status in a population with a high prevalence of diabetes. RESEARCH DESIGN AND METHODS: We analyzed the oral glucose tolerance tests (OGTTs) carried out at the Instituto Nacional de la Nutrición Salvador Zubiran (INNSZ) central laboratory from June to December 1997. We included patients with fasting plasma glucose (FPG) between 60 and 160 mg/dl. The results from the glucose tolerance test were selected as the gold standard. RESULTS: Among the 1,802 glucose tolerance test results available for analysis, 1,706 fulfilled the requirements to be included. Diabetes and IGT were remarkably more frequently diagnosed when the WHO criteria were applied. The new ADA criteria failed to diagnose 69% of WHO diabetic patients and the vast majority of WHO glucose-intolerant subjects. Using the new criteria, 82% were considered normal. Of the IFG subjects, 39% were classified as diabetic and 23% were normal according to the 2-h postchallenge glucose values. Only 37% of the IFG patients were, in fact, glucose intolerant according to the WHO criteria. CONCLUSIONS: Our results clearly show that the 1997 ADA criteria are less sensitive for diagnosing diabetes than OGTT-based WHO criteria. Even more important, there is poor agreement between the WHO category of IGT and the ADA category of IFG.

[Four cases of parathyroid cancer]. / Cuatro casos de cáncer de paratiroides.

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism with a prevalence ranging between 0.5 and 4%. Because of their aggressiveness, prompt diagnosis and treatment are mandatory. A parathyroid carcinoma was found in four patients (4.5%) of 88 patients who underwent surgical cervical exploration for primary hyperparathyroidism at the Institute Nacional de la Nutrición in a period of seven years. Our paper gives the clinical characteristics, diagnosis, treatment and outcome of the four patients.

Cardiac abnormalities associated with morbid obesity.

Morbidly obese patients are at increased risk for structural and functional abnormalities of the heart. This paper summarizes the effects of obesity on the heart, the effect of weight reduction on cardiac function, the impact of coronary artery disease on cardiac cardiomyopathy, and our experience in obesity heart disease at the Instituto Nacional de la Nutrición in Mexico.

[Laparoscopic adrenalectomy in a mexican institution]. / La adrenalectomía laparoscópica en una institución mexicana.

AIM: To analyze the general characteristics and outcome of laparoscopic adrenalectomy in our institution. METHODS: The clinical and intraoperative characteristics, complications and outcome of 29 consecutive patients undergoing lateral transperitoneal laparoscopic adrenalectomy between February 1995 and January 1998 were analyzed. RESULTS: Their mean age was 34 +/- 11 years, 6 were males and 23 females. The most common preoperative diagnosis was recurrent Cushing's disease followed by functioning adenomas and pheochromocytomas. There were 17 unilateral and 12 bilateral adrenalectomies. The mean operative time was 2.5 +/- 1 hours for each gland. Two patients were converted to the open technique. There were two complications: a wound infection and a postsurgery hypoglycemia. The hypoglycemic patient also developed massive upper gastrointestinal bleeding 18 days after surgery and died. The mean postoperative hospital stay was 5 days. In a mean follow-up of one year, recurrence of one pheochromocytoma was seen. CONCLUSION: Laparoscopic adrenalectomy was a safe operation that favored early recovery.

An ectopic adrenocorticotropic hormone syndrome caused by a sacrococcygeal chordoma: report of a case with a slow progression.

OBJECTIVE: To report the first case of an ectopic adrenocorticotropic hormone (ACTH) syndrome caused by a sacrococcygeal chordoma. METHODS: We present a case report with clinical, laboratory, and histologic details. RESULTS: A 76-year-old man was admitted to the hospital because of urinary obstruction. Five years previously, a urethral mass had been detected, and transurethral prostatectomy had been performed. Annual computed tomographic (CT) scans showed no change in size of the mass. In 1995, skin hyperpigmentation, central obesity, and bilateral edema were noted. The patient was admitted to the hospital in July 1996. A CT scan of the abdomen revealed a large mass close to the sacrum and compressing the bladder and rectum. Cortisol measurements (AM and PM) were 309 and 271 ng/mL, respectively. The plasma ACTH concentration was extremely elevated (3,125 pg/mL). Although resection of the mass was attempted, complete resection was not possible because the tumor had infiltrated the sacrum. Plasma cortisol concentrations in samples obtained 7 and 8 days postoperatively were normal. Plasma ACTH was substantially decreased (180 pg/mL) but remained above normal. The histologic features of the tumor were compatible with a chordoma. Neoplastic cells stained positively for ACTH. CONCLUSION: This report describes the first case of an ectopic ACTH syndrome caused by a sacrococcygeal chordoma. A slow progression of symptoms in an ectopic ACTH syndrome had been described only for carcinoid tumors. These data add a new entry to the list of neoplasms capable of causing this syndrome.

The first 50 cases of primary hyperparathyroidism treated by an endocrine surgery team.

BACKGROUND: Primary hyperparathyroidism (HPT) is a common endocrine disease treated very effectively by surgery. There have been changes in the management of parathyroid surgery in our hospital: since 1991, all patients have been treated by a service of endocrine surgery. OBJECTIVE: To analyze the outcome of the first 50 patients treated in the endocrine surgery service. METHODS: A prospective analysis of clinical characteristics, laboratory studies, intraoperative findings, surgical complications and outcome of 50 patients with primary HPT seen between July 1991 and March 1994 was performed. RESULTS: Ten patients were male and 40 female with a mean age of 53 years. A parathyroid adenoma was found in 43 patients, a parathyroid hyperplasia in five, a double adenoma in one and an adenoma in a supernumerary gland in one patient. Surgical cure of the disease was achieved in 96% of the patients after one surgical procedure and in 100% during the same hospital stay after repeat cervical exploration. CONCLUSIONS: Our results support the use of surgical cervical exploration in the treatment of primary HPT.

Efficacy of fine-needle aspiration biopsy of thyroid nodules: experience of a Mexican institution.

In most centers only selected patients with high risk thyroid nodules undergo thyroid surgery, and fine needle aspiration biopsy (FNA) is used to select patients for surgical treatment. The aim of the present study was to evaluate the impact of FNA on the management of thyroid nodules at our institution. A total of 872 patients who underwent FNA over a period of 7 years were retrospectively analyzed. There were 66 men and 806 women with a mean age of 40 +/- 15 years. Altogether 549 patients presented with a thyroid nodule and 323 with multinodular disease. The sensitivity and specificity of FNA were 90.0% and 99.8%, respectively. The positive and negative predictive values were 98% and 99%, respectively, and the accuracy was 99%. Our results are in agreement with those of other reports establishing that FNA of the thyroid is safe, reliable, and effective for differentiating benign from malignant nodules.

[Surgical treatment of multinodular goiter at the Instituto Nacional de la Nutrición Salvador Zubirán]. / Tratamiento quirúrgico de bocio multinodular en el Instituto Nacional de la Nutrición Salvador Zubirán.

BACKGROUND: Surgical treatment is the first option for patients with obstructive multinodular goiter. The extent of the resection and the use of postoperative hormonal therapy are, on the other hand, still under debate. OBJECTIVE: To analyze the results of surgical treatment in 101 patient with multinodular goiter seen from 1980 to 1995. MATERIALS AND METHODS: The clinical/pathologic charts of all patients were reviewed with emphasis to the clinical diagnosis, extent of resection, final histology, type and number of complications, and long-term follow-up. The mean follow-up was three years (range 0.5-12). RESULTS: Ten males and 91 females with a mean age of 46 years were included. Surgery was recommended for a nodule suspicious of malignancy in 60 patients, for airway compression in 33, and for cosmetic reasons in eight. Unilateral lobectomy was performed in 30, bilateral subtotal thyroidectomy in 55 and total thyroidectomy in 16. Postoperative hormone therapy was administrated to 83 patients. Surgical complications occurred in six patients. Four developed permanent hypoparathyroidism and two vocal cord paralysis. There was no operative mortality. A final diagnosis of multinodular goiter was established in 89 whereas 12 had cancer. There were three asymptomatic recurrences in the group with benign lesions (they had undergone unilateral lobectomy followed by hormonal therapy). CONCLUSION: Bilateral subtotal thyroidectomy was the best treatment for multinodular goiter in our series. This procedure had few complications and there was no recurrence of the disease.

[Anaplastic carcinoma of the thyroid at the Instituto Nacional de la Nutrición Salvador Zubirán]. / Carcinoma anaplásico de tiroides en el Instituto Nacional de la Nutrición Salvador Zubirán.

BACKGROUND: Anaplastic thyroid carcinoma (ATC) is a highly aggressive tumor with a median survival rate of 6 months. AIM: To analyze presentation, treatment, morphology, immunohistochemistry, and nuclear DNA analysis of a cohort of patients with ATC. PATIENTS AND METHODS: Twelve patients with ATC (11 female) with a mean age of 65 years were seen at our hospital from 1970-1995. The data were obtained from the clinical records and the morphology, immunohistochemic studies and DNA pattern were performed in slides obtained from archival specimens. RESULTS: Previous or coexisting thyroide disease was documented in 10 patients (9 multinodular goiters and one Grave's). The most frequent presentation was a rapidly growing tumor associated with dysphagia, cervical pain, hoarseness and dyspnea. A cold thyroid nodule was detected by thyroid scan in 10 patients. The most frequent subtype was the spindle cell variety. Papillary thyroid carcinoma coexisted in eight cases, two of them corresponded to the tall cell variant. Reactivity for S-100 protein and vimentin was studied in six patients: all were positive for S-100 protein and vimentin, 5/6 for epithelial membrane antigen, half for carcinoembriogenic antigen, 2/6 for thyroglobulin and calcitonin, and one for neuronal specific enolase. These six tumors showed a diploid DNA pattern. Tumor resection was achieved in 2/11 and none survived six years after diagnosis. CONCLUSIONS: ATC is a highly aggressive tumor coexisting with thyroid pathologies. Spindle cell variant is the most frequent with positive reactivity for S-100 protein, vimentin and epithelial membrane antigen. Most tumors have a diploid DNA content.