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Biomedical subjects

M F Herrera

Publications and source records attributed to M F Herrera.

At least 19 recordsLinked to original sources
PubMed2005

Laparoscopic Heller myotomy for classic achalasia: results of our initial series of 20 patients.

BACKGROUND: The aim of this study was to review our results in the surgical management of achalasia by laparoscopic esophageal cardiomyotomy and partial fundoplication. METHODS: The patient population was comprised of a consecutive series of 20 patients with classic achalasia who underwent laparoscopic cardiomyotomy and partial fundoplication. Clinical, radiological, and physiological characteristics were analyzed prospectively, with an emphasis on the outcome and complications. RESULTS: There were 12 women and eight men; their mean age was 37 years. Four intraoperative complications occurred-two mucosal perforations that were resolved laparoscopically and two cases of pneumothorax. The median hospital stay was 4 days (range, 2-14) and the median time to start oral feeding was 3 days (range, 1-7). After a median follow-up of 14 months (range, 2-83), 16 patients were asymptomatic and four had mild heartburn and/or dysphagia. All patients gained weight (median, 8.0 kg; range, 1-23). We observed a median postoperative decrease in esophageal diameter of 1.6 cm (range, 0.2-2.9). Fifteen patients were subjected to physiological esophageal studies; the results showed that power esophageal sphincter pressure had decreased from 32 (range, 15-60) to 12 mmHg (range, 6-25). The median DeMeester score was 14.5 (range, 0.9-194). The median esophageal acid exposure was 3% (range 0-34.6). CONCLUSIONS: Our initial experience with the laparoscopic management of classic achalasia yielded satisfactory clinical, radiological, and physiological results.

Adolescent↗
PubMed2004

Laparoscopic drainage of pancreatic pseudocysts.

BACKGROUND: Laparoscopic drainage of pancreatic pseudocysts (PPs) has been used in selected cases. The aim of this study is to analyze our results with the laparoscopic technique and to compare them with those of a cohort of patients treated by open surgery during the same time period. PATIENTS AND METHODS: Ten patients underwent laparoscopic drainage of PPs during a 7-year period [laparoscopic group (LG)]. The type of drainage was chosen according to the size and location of the PP. Demography, surgical details, results, and complications were analyzed and contrasted with those of 6 patients who underwent open drainage [open group (OG)]. RESULTS: All patients presented with mature PPs developed after a documented episode of acute pancreatitis. Mean age of the LG was 42 years (six males and four females). In the OG, mean age was 36 years (five males and one female). Etiology of the pancreatitis was alcoholic in eight patients, biliary in five, toxic in two, and associated with systemic lupus erythematous in one. Laparoscopic procedures included Roux-en-Y cystojejunostomy in four patients, extraluminal cystogastrostomy in four, and intraluminal cystogastrostomy in two. There were no conversions. In the OG, cystogastrostomy was performed in three patients and Roux-en-Y cystojejunostomy in three. One patient in the LG developed upper gastrointestinal bleeding the day after surgery that resolved uneventfully, one patient presented a postoperative abscess that required open drainage, and one patient presented a residual pseudocyst that was treated by endoscopy. Morbidity in the OG included a small bowel obstruction secondary to an internal hernia that required reoperation, pneumonia, and a residual pseudocyst that was treated conservatively in one patient each. At a median follow-up of 22 months (range, 1-72) all patients were asymptomatic with no evidence of recurrent disease by computed tomography scan. CONCLUSION: Laparoscopic drainage of PPs is feasible, safe, and effective. Results are similar to those obtained using the open technique.

Adolescent↗
PubMed2004

Adrenal incidentaloma.

Adrenal incidentalomas are tumors that are serendipitously found by radiological examination. The incidence of adrenal incidentalomas in patients undergoing abdominal CT approaches 1 %. The evaluation of a patient with an adrenal incidentaloma requires, in addition to a clinical history and physical examination, a focused biochemical evaluation to investigate if there is excess secretion of catecholamines, glucocorticoids, or aldosterone. Some tumors have specific features on imaging that identify them as benign or malignant. The recommendations for management of adrenal incidentalomas include resection of all functioning tumors regardless of size, preferably by the laparoscopic approach. Large, non-functional tumors should also be removed. Biochemical and radiological surveillance is recommended for at least one year, if a tumor is left in place.

Adrenal Gland Neoplasms↗
PubMed2002

Laparoscopic approach to fever of unknown origin.

BACKGROUND: Fever of unknown origin (FUO) is difficult to diagnose. Laparotomy is needed to establish the etiologic diagnosis in some patients. The aim of this study was to analyze the feasibility, safety, and success rate of a protocolized laparoscopy in patients with FUO. METHODS: An extensive clinical evaluation was performed before surgery. Laparoscopy included inspection of the abdominal cavity, wedge and tru-cut liver biopsies, lymph node biopsy, splenectomy, and bone marrow biopsy. Histologic analysis, permanent section analysis, and cultures were obtained. RESULTS: The study involved 15 patients with a mean age of 43.6 +/- 14.5 years. The mean operative time was 122 +/- 60 min. Minor complications occurred in 9% of the patients. One patient bled after surgery and underwent reoperation. There was no operative mortality. An etiologic diagnosis was made in 66% of the patients, and laparoscopy helped to rule out intraabdominal pathology in four additional patients, giving a total success rate of 93%. CONCLUSION: Protocolized laparoscopy in patients with FUO is safe, feasible, and accurate.

Feasibility Studies↗
PubMed2001

Accuracy of sentinel lymph node in papillary thyroid carcinoma.

BACKGROUND: The sentinel lymph node has been used in several tumors. The aim of this study was to analyze the accuracy of the sentinel node in papillary thyroid carcinoma. METHODS: A series of 22 patients with papillary thyroid carcinoma were included. Approximately 0.5 cc of isosulfan blue dye was injected at operation to trace the sentinel node. Lymph node dissection of the ipsilateral central compartment and extensive sampling of the jugular compartment were performed in addition to sentinel node resection. Surgical specimens were stained with hematoxylin-eosin, and negative sentinel nodes were subsequently stained with immunohistochemistry for cytokeratin-7. RESULTS: Mean age was 37 +/- 14 years. Twenty patients were women, and 2 were men. Mean tumor size was 2.5 +/- 1 cm. A sentinel lymph node was found in 20 patients. With use of hematoxylin-eosin, metastases were identified in 12/20 sentinel nodes (60%). Eleven patients with positive sentinel nodes presented additional lymph node metastases: 9 in the central compartment, 1 in the jugular compartment, and 1 in both compartments. Two patients with negative sentinel nodes had lymph node metastases elsewhere. When sentinel nodes were processed by immunohistochemistry, accuracy increased to 100%. CONCLUSIONS: Sentinel node is highly accurate for diagnosing metastases in papillary thyroid carcinoma.

Adult↗
PubMed2001

Histologic diagnosis of primary hyperparathyroidism: a concordance analysis between three pathologists.

Primary hyperparathyroidism (HPT) is caused by a parathyroid adenoma, hyperplasia or carcinoma. Difficulties for the histologic diagnosis of abnormal parathyroid tissue are widely recognized. The aim of the study was to evaluate the reproducibility of the morphologic criteria through a concordance study among three pathologists. Representative slides of 40 patients with biochemically primary HPT stained with hematoxylin and eosin were blindly reviewed by three pathologists. Each pathologist established the diagnosis of adenoma or hyperplasia and assessed the presence of fat cells, a rim of normal tissue, a fibrous capsule, the number of cellular types, the lobular pattern, and the characteristics of the blood vessel's wall. A concordance analysis was then performed. Mean age of the group was 55 +/- 14 yr, 7 were males and 33 females. The concordance analysis among the three pathologists for the differential diagnosis between adenoma and hyperplasia, showed a Kappa index of 0.5. Kappa index for the presence of fat cells was 0.56, for the presence of a rim of normal tissue 0.47, and for the number of cellular types 0.29. The concordance for the differential diagnosis between parathyroid adenoma and hyperplasia in this study was low.

Adenoma↗
PubMed2000

Open vs. laparoscopic vertical banded gastroplasty: a case control study with a 1-year follow-up.

BACKGROUND: Vertical Banded Gastroplasty (VBG) is one of the most common bariatric operations. It can be performed by open or laparoscopic methods. The purpose of this study was to analyze and compare the 1-year results of 40 patients who underwent laparoscopic (20) and open (20). METHODS: The initial 20 patients undergoing Laparoscopic VBG and the initial 20 patients in whom an Open VBG were performed in our Institution were comparatively evaluated. Demography, surgical details, complications, and 1-year weight loss were analyzed. RESULTS: Both groups were highly comparable in terms of age, sex and body mass index. Laparoscopic VBG was a more prolonged procedure (median 4 hr) than the open VBG (median 3 hr). On the other hand, hospital stay was significantly shorter in the laparoscopic procedure (median 10 days for the open and 6 days for the laparoscopic). One year weight loss and complications were similar in both groups. CONCLUSIONS: Laparoscopic VBG is a safe procedure for the treatment of morbid obesity. This initial series shows comparable results.

Adult↗
PubMed1999

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.

Adenoma↗
PubMed1999

Role of radiologic contrast studies in the early postoperative period after bariatric surgery.

BACKGROUND: Radiologic contrast studies have been used routinely to rule out gastrointestinal (GI) leaks and to evaluate gastric emptying after bariatric surgery. The aim of the study was to evaluate the value of this study in the diagnosis of early complications. PATIENTS AND METHODS: 100 morbidly obese patients underwent bariatric surgery at our institution in a 7 year period. An upper GI series was routinely performed 48 to 72 hours after surgery. Clinical and radiologic records were reviewed, analyzing demographic characteristics, type of surgery, radiologic findings, and clinical evolution with emphasis on the presence of leaks. RESULTS: Mean age was 36 +/- 10 years; there were 68 women and 32 men. Mean body mass index (BMI) was 48 +/- 10 kg/m2. All radiologic examinations ruled out the presence of leaks and showed adequate gastroesophageal emptying. One patient with normal postoperative x-ray studies developed a small GI fistula after starting liquid diet. CONCLUSIONS: Contrast radiologic studies permit good visualization of the gastric anatomy after bariatric surgery. They usually confirm adequate gastric emptying, but might be unable to demonstrate small gastric leaks.

Adult↗
PubMed1998

Anesthesia for morbidly obese patients.

Bariatric surgery is the most effective method for treating patients with morbid obesity, and participation of the anesthesiologist in the treatment of these patients is more and more frequent. Therefore it is important for anesthesiologists to be familiar with anatomic and physiologic implications and the pharmacologic changes associated with obesity, so they can offer optimal perioperative treatment. The present study describes a series of 37 patients with an average body mass index of 50.3 kg/m2 who underwent bariatric surgery in a third-level teaching hospital in Mexico City. Preoperative assessment, airway management, perioperative treatment, and the incidence of complications are analyzed. We found a high frequency of associated diseases, among which diabetes mellitus and systemic arterial hypertension were the most prominent. Cardiorespiratory complications such as obstructive sleep apnea syndrome and obesity-hypoventilation syndrome were particularly frequent (16.2% and 22.0%, respectively). Both general anesthesia and mixed anesthesia (peridural block plus light general anesthesia) were employed. The incidence of complications related to perioperative and anesthetic management was low. We discuss and propose protocols for the evaluation and management of airway and associated cardiorespiratory complications.

Adult↗
PubMed1998

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.

Cardiomyopathies↗
PubMed1998

Laparoscopic versus open splenectomy for immune thrombocytopenic purpura.

BACKGROUND: Laparoscopic splenectomy (LS) has been proposed as a substitute to open splenectomy (OS) in the treatment of immune thrombocytopenic purpura (ITP). The aim of this study was to compare two cohorts of patients with ITP who underwent OS or LS. PATIENTS AND METHODS: From February 1990 to January 1997, 27 patients underwent OS and 22 LS. Perioperative characteristics, outcomes, and complications were comparatively analyzed. RESULTS: Mean age was 38 years (+/- 16) in the OS group, and 39 (+/- 16) in the LS group; the male: female ratio was 1:2 in both groups. Median preoperative platelet count was 16 x 10(9)/L (range 2 to 186 x 10(9)/L) in the OS group, and 50 x 10(9)/L (2 to 241 x 10(9)/L) in the LS group. Mean operative time was 2.7 hours (+/- 0.7) for OS, and 4.5 hours (+/- 1) for LS (P <0.0001). Two conversions to laparotomy occurred in the LS group. A total of 14 complications occurred in 10 patients of the OS group; 8 complications occurred in 6 patients of the LS group. Two patients died in the OS group and 1 in the LS group. Mean postoperative discharge was 6 days (3 to 44) in the OS group and 4 days (2 to 11) in the LS group (P <0.02). Response rates were similar in both groups. CONCLUSIONS: Laparoscopic splenectomy is comparable to OS in terms of efficacy and safety, and it is associated with a shorter hospital stay.

Adult↗
PubMed1998

Prospective biochemical and scintigraphic evaluation of autografted normal parathyroid glands in patients undergoing thyroid operations.

BACKGROUND: Parathyroid autotransplantation has been widely used in thyroid operations. Few studies have assessed the function of the autotransplanted glands. The aim of this study was to evaluate the success rate, pattern of biochemical function, and scintigraphic appearance of parathyroid autografts in patients undergoing thyroid operations. METHODS: Twelve patients in whom 1 parathyroid gland was removed during thyroid operation were included. Glands were fragmented and autografted into individual pockets in the brachioradialis muscle of the nondominant forearm. Parathyroid hormone levels were measured in both arms the day of autotransplantation and 2 weeks and 1, 2, 3, and 6 months after operation. Serum calcium levels were also measured at each interval. Sestamibi scanning was performed 6 months after operation in 7 patients. RESULTS: All patients were women with a mean age of 50 +/- 15 years. Serum calcium levels were normal during follow-up. A gradient of parathyroid hormone level of 1.5 or greater between the autotransplanted and nontransplanted arm was found in 10 patients. Isotope uptake at the site of the parathyroid autotransplant was demonstrated in the 7 patients evaluated. CONCLUSIONS: Biochemical function of autotransplanted normal parathyroid tissue was documented in 83% of the patients. Sestamibi scintiscans were able to identify the autotransplanted tissue.

Adult↗
PubMed1997

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.

Adolescent↗
PubMed1997

Pain relief in chronic pancreatitis by pancreatico-jejunostomy. An institutional experience.

Effective pain control in chronic pancreatitis can be accomplished by pancreatic resection or decompression. Pancreatico-jejunostomy (PJ) has been reported to be effective for relieving pain in 70-80% of cases. The present study analyzes the authors' long-term results with PJ in the treatment of pancreatic pain. From 1963 to 1993, 49 patients with chronic pancreatitis underwent PJ for uncontrollable pain. General and radiologic characteristics, intraoperative findings and outcome were analyzed. Mean age was 35 +/- 13 years, 34 were male and 15 female. Alcoholic etiology was documented in 23 patients. Multiple pancreatic calcifications were found in 33 patients. Pancreatic biopsy confirmed chronic pancreatitis in all patients. There was one operative mortality, 12 minor, and 4 major complications. In a mean follow-up of 6.5 years, 98% of the total group was found to be free of pain. Pancreatic function remained stable in most patients. PJ is an excellent procedure for pain control that allows stable pancreatic function.

Adult↗
PubMed1996

Papillary thyroid carcinoma in Mexican patients: clinical aspects and prognostic factors.

The present study characterizes papillary thyroid carcinoma (PTC) in a Mexican patient sample and evaluates potential prognostic factors for recurrence. Clinical records of 229 patients with PTC were analyzed. Surgical specimens were rereviewed and DNA ploidy determined. Cox logistic regression was used to explore prognostic factors. Mean age +/- SD of the patients was 42 +/- 16 years, with a male/female ratio of 24:205. A thyroid mass was the initial manifestation in 99%. Extrathyroid invasion occurred in 45% and nodal metastases in 38%. Mean size +/- SD of the tumors was 3 +/- 2 cm. By flow cytometry 88% of the tumors were DNA euploid and 12% aneuploid. Complete tumor resection was achieved in 83% with an operative mortality of 0.4%. Postoperative hormone suppression was administered in 65% and remnant 131I thyroid ablation in 84%. The 10-year recurrence-free survival was 85%. In the group of patients with tumors totally removed and without distant metastases, none of the 14 evaluated variables demonstrated statistical significance as an independent prognostic factor for recurrence. However, the group of patients in whom a combination of the following factors was present--age > or = 40 years, tumor size > or = 3 cm, local invasion, and lymph node metastases--showed a higher incidence of tumor recurrence.

Adult↗
PubMed1996

Early experience with laparoscopic resections of islet cell tumors.

BACKGROUND: Diagnostic laparoscopy and laparoscopic ultrasonography have been applied recently for diagnosis and localization of islet-cell tumors. A further step was taken by performing resection of these tumors with laparoscopic techniques. METHODS AND RESULTS: We studied a retrospective series of 12 patients operated on with laparoscopic techniques since January 1992. The seven female and five male patients had a mean age of 43 years. The mean tumor size was 3 cm. Thirty-six percent of the tumor site could not be identified before operation. Eight patients underwent planned laparoscopic distal pancreatectomy (five insulinomas, two gastrinomas, and one unknown origin), and four underwent planned laparoscopic enucleation (one insulinoma and three unknown origin). Of the eight distal procedures, three had conversions (one inability to localize the tumor and two metastatic gastrinomas). Average operating time was 4.5 hours, with an average hospital stay of 5 days. Of the four explorations for possible enucleation, one was performed and one was converted to a Whipple procedure for nesidioblastoma of the head of the pancreas. The other two had negative explorations. The successful enucleation of an insulinoma of the anterior body of the pancreas was performed in 3 hours, and the hospital stay was 4 days. No recurrence was seen in the enucleated or distal pancreatectomy group in follow-up (15 to 38 months). CONCLUSIONS: Laparoscopic enucleation or resection of benign islet tumors results in a shorter hospital recovery and is a good alternative to open surgery.

Adenoma, Islet Cell↗