Development of a tool to calculate the probability of hypocalcemia after total thyroidectomy: a prospective study.

PURPOSE: This study aimed to evaluate the ability of the percentage of decrease in serum PTH level in the first 8 h after total thyroidectomy (TT) to predict hypocalcemia requiring Ca supplementation and develop a tool to predict it. METHODS: 97 patients who underwent TT with measurement of preoperative parathyroid hormone (PTH) levels were prospectively evaluated 1 and 8 h after TT; postoperative magnesium (Mg2PO) and phosphorus levels were evaluated on the 2nd day after surgery. The percentage of decrease in PTH level 1 h (%dPTH1h) and 8 h (%dPTH8h) postoperatively and predictors of hypocalcemia requiring Ca supplementation were evaluated and an equation was developed to predict this outcome. RESULTS: %dPTH1h (p = 0.002), %dPTH8h (p = 0.001) and (Mg2PO) (p < 0.01) were isolated predictors of postoperative hypocalcemia requiring Ca supplementation. The data obtained led to the development of two tools to predict this complication. CONCLUSIONS: The percentage of decrease in PTH level 1 h and 8 h postoperatively and the magnesium level on the 2nd day after surgery were predictors of more severe hypocalcemia, and an auxiliary tool for predicting this complication was developed.

Basal or stimulated thyroglobulin in evaluating response to treatment in papillary thyroid carcinoma? A retrospective cohort study.

OBJECTIVE: It is not clear whether response to initial treatment in papillary thyroid carcinoma (PTC) patients is best evaluated by measuring thyroglobulin (Tg) in the presence of levothyroxine (BTg) or when stimulated by elevated TSH (STg). The aim of this study was to evaluate whether response to therapy 1 year after initial treatment changes with the use of STg in relation to BTg in PTC patients treated with total thyroidectomy (TT) and radioiodine (131I), and, if observed, to assess which response is better associated with clinical course. SUBJECTS AND METHODS: This is a retrospective study of 148 PTC patients submitted to TT and 131I. We analyzed the response to therapy (excellent, biochemical incomplete, or indeterminate) at 1 year after initial treatment, using BTg or STg, and compared which method was better associated with "excellent response at final evaluation." RESULTS: Twenty-eight patients (20.4%) presented change in response to therapy, with 17 of these (60.7%) presenting a worse response. Response using STg was 1.6 times better associated with proposed outcome [odds ratio (OR) = 4.61; confidence interval 95% (IC95%): 2.13-9.98] than with BTg (OR = 2.84; IC95%: 1.33-6.06). CONCLUSION: Response to therapy at 1 year using STg was altered in approximately 20% of cases and therefore proved to be a better predictor of excellent response in the last evaluation.

Postoperative serum magnesium levels as a predictor for the need for calcium replacement after total thyroidectomy: a prospective study

ABSTRACT Objective: Our aim was to assess the ability of serum magnesium (Mg), measured on the first postoperative day (Mg1PO), to predict the need for calcium (Ca) replacement in patients undergoing total thyroidectomy (TT). Subjects and methods: Eighty patients undergoing TT, with Mg1PO and PTH dosage in the first (PTH1h) and eighth (PTH8h) hours after TT, were evaluated for the need for Ca replacement. Data were evaluated by uni/multivariate logistic regression and Receiver Operating Characteristic (ROC) curve. Results: 32 patients (40%) required Ca replacement. Median PTH1h, PTH8h and Mg1PO were higher in the no replacement group: 17 versus (vs) 3 pg/mL (p < 0.001), 18.2 vs 3.0 pg/mL (p < 0.001) and 2 vs 1.6 mg/dL (p < 0.001), respectively. Mg1PO was the isolated predictor for this replacement (odds ratio = 0.0004, 95% confidence interval: 0.000003-0.04; p = 0.001), with the cut-off value of 1.8 mg/dL showing sensitivity and specificity of 78.1% and 87.5%, respectively. Conclusions: In this group of patients, serum Mg1PO was the isolated predictor for the need for Ca replacement.

Association between Clinical and Histopathological Findings in Intestinal Neuronal Dysplasia Type B: An Advance towards Its Definition as a Disease.

INTRODUCTION: Intestinal neuronal dysplasia type B (IND-B) is a controversial entity that affects the submucosal nerve plexus of the distal intestine. The lack of definition of the causal relationship between histological findings and clinical symptoms has been identified as the primary point to be elucidated in the scientific investigation related to IND-B, which is essential for it to be considered a disease. OBJECTIVE: To investigate the relationship between histopathological findings and symptoms in a series of patients with IND-B. METHODS: Twenty-seven patients with histopathological diagnosis of IND-B, according to the Frankfurt Consensus (1990), who underwent surgical treatment through colorectal resections were included. Data from medical records regarding the clinical picture of the patients at the time of diagnosis, including the intestinal symptom index (ISI) and a detailed histopathological analysis of the rectal specimens, were retrieved. Exploratory factor analysis was performed, applying the principal components method for clusters with Varimax rotation. RESULTS: Two factors were determined: the first, determined by histopathological and clinical variables, and the second, composed of the main symptoms presented in patients with IND-B, including ISI. Factorial rotation showed the association between the two factors and, through a graph, demonstrated the proximity between ISI values and histopathological alterations. CONCLUSION: There was evidence of an association between the clinical features presented by patients with IND-B and the histopathological findings of the rectal samples. These results support the understanding of IND-B as a disease.

Postoperative serum magnesium levels as a predictor for the need for calcium replacement after total thyroidectomy: a prospective study.

Objective: Our aim was to assess the ability of serum magnesium (Mg), measured on the first postoperative day (Mg1PO), to predict the need for calcium (Ca) replacement in patients undergoing total thyroidectomy (TT). Subjects and methods: Eighty patients undergoing TT, with Mg1PO and PTH dosage in the first (PTH1h) and eighth (PTH8h) hours after TT, were evaluated for the need for Ca replacement. Data were evaluated by uni/multivariate logistic regression and Receiver Operating Characteristic (ROC) curve. Results: 32 patients (40%) required Ca replacement. Median PTH1h, PTH8h and Mg1PO were higher in the no replacement group: 17 versus (vs) 3 pg/mL (p < 0.001), 18.2 vs 3.0 pg/mL (p < 0.001) and 2 vs 1.6 mg/dL (p < 0.001), respectively. Mg1PO was the isolated predictor for this replacement (odds ratio = 0.0004, 95% confidence interval: 0.000003-0.04; p = 0.001), with the cut-off value of 1.8 mg/dL showing sensitivity and specificity of 78.1% and 87.5%, respectively. Conclusion: In this group of patients, serum Mg1PO was the isolated predictor for the need for Ca replacement.

PTEN Immunohistochemistry.

CONTEXT.­: Intestinal neuronal dysplasia type B (IND B) is a complex entity involving the enteric nervous system, clinically manifested with constipation in infancy. Diagnosis has been established by histopathologic analysis of rectal biopsies. However, the criteria for the diagnosis have been questioned and modified, hindering diagnostic practice. OBJECTIVE.­: To analyze the applicability of PTEN immunohistochemistry in the diagnosis of IND B and to compare with control cases and cases of Hirschsprung disease (HD). DESIGN.­: PTEN immunohistochemical expression was analyzed in colorectal samples from 29 cases of IND B and compared with 4 control cases and 6 cases of HD. The pattern of PTEN immunoexpression was analyzed in glial cells of the submucosal and myenteric nerve plexuses and in neural fibrils of the muscularis propria using a scoring system. RESULTS.­: Marked reduction or absence of PTEN expression was observed in glial cells of the submucosal nerve plexuses in all cases of the IND B group and in the myenteric nerve plexuses in 28 of 29 cases (96.5%). Lack of PTEN expression was detected in neural fibrils within the muscularis propria in 21 of 29 cases (72%) of the IND B group. PTEN expression was positive in the same neural structures of the control and HD groups. CONCLUSIONS.­: PTEN immunohistochemistry may be a valuable tool in the diagnostic evaluation of IND B. Lack of or reduction of PTEN expression in neural fibrils within the muscularis propria suggests that involvement of the neuromuscular junction may be a key event in the pathogenesis of the motility disturbance occurring in IND B.

Agreement between histopathological and intraoperative classifications for pediatric appendicitis and its relationship with the post-operative clinical outcome.

Introduction: Some studies have shown poor agreement between intraoperative and histopathological classifications for appendicitis, despite their routine use in clinical practice. Objective: To investigate the agreement between histopathological and intraoperative classifications for pediatric appendicitis and evaluate the predictive potential of these classifications for the post-operative outcome. Methods: A retrospective, longitudinal, observational single-center study, carried out with 485 patients up to15 years of age, with a confirmed diagnosis of acute appendicitis by histopathological evaluation. The histopathological results classified the appendices as uncomplicated appendicitis when there was confirmation of the diagnosis of appendicitis without necrosis or perforation and complicated appendicitis when there was extensive necrotic tissue in the outer layer of the appendix or signs of perforation. The intraoperative findings were classified as uncomplicated appendicitis when the appendix presented with hyperemia and edema or fibrinous exudate and complicated appendicitis when the appendix showed necrosis, abscess, or perforation. The kappa index determined the agreement and the prediction relationships using a generalized linear model. Results: 43.9% of cases were classified as complicated appendicitis by histopathological evaluation and 49.7% by intraoperative classification. The agreement analysis between the histopathological and intraoperative classification showed a moderate agreement, with a Kappa index of 0.419 (0.337-0.501). There was an association (P < 0.05) between the intraoperative classification and the post-operative clinical outcomes (time to start feeding, fever, intraabdominal collection, length of stay, the need for antibiotic therapy changing, and need for ICU). There was no association between histopathological classification and post-operative outcomes. Conclusion: The agreement between the two classifications was moderate, and the intraoperative classification was able to predict the post-operative clinical outcomes.

Challenges in the diagnosis of intestinal neuronal dysplasia type B: A look beyond the number of ganglion cells.

Intestinal neuronal dysplasia type B (IND-B) is a controversial condition among gastrointestinal neuromuscular disorders. Constipation is its most common clinical manifestation in patients. Despite intense scientific research, there are still knowledge gaps regarding the diagnostic criteria for IND-B in the histopathological analysis of rectal biopsies. The guidelines published in the past three decades have directed diagnostic criteria for quantifying the number of ganglion cells in the nervous plexus of the enteric nervous system. However, it is very complex to distinguish numerically what is pathological from what is normal, mainly because of the difficulty in determining a reliable control group composed of healthy children without intestinal symptoms. Thus, a series of immunohistochemical markers have been proposed to assist in the histopathological analysis of the enteric nervous system. Several of these markers facilitate the identification of other structures of the enteric nervous system, in addition to ganglion cells. These structures may be related to the etiopathogenesis of IND-B and represent new possibilities for the histopathological diagnosis of this disease, providing a view beyond the number of ganglion cells. This review critically discusses the aspects related to the disease definitions and diagnostic criteria of this organic cause of constipation.

Are biopsies always necessary in upper and lower gastrointestinal endoscopy in children? A retrospective 10-year analysis.

Little attention has been given to the efficiency and validity of performing routine endoscopic biopsies in normal areas in children. This study aimed to investigate the need to perform routine biopsies in upper gastrointestinal endoscopy (UDE) and colonoscopy in normal areas by comparing macroscopy and histology. It was a 10-year retrospective analysis with the inclusion of 761 UDEs and 177 colonoscopies. Considering all segments, UDEs showed false-positive result rates of 73.11% and false-negative result rates of 14.34%. The histological results modified the initial management in 53.95% of patients. Considering all segments, colonoscopies showed false-positive result rates of 63.64% and false-negative result rates of 30.97%. The histological results modified the initial management in 34.45% of patients.Conclusion: If biopsies were obtained only in abnormal areas, the diagnosis would be lost in 53.95% of the patients in upper endoscopies and 85.7% of the colonoscopies, which justifies routine maintenance of biopsies in macroscopically normal areas in children. What is Known: • Little attention has been given to the efficiency and validity of endoscopic biopsies of normal areas during pediatric exams. • Only a few pediatric studies have correlated macroscopic and histological findings from endoscopic biopsies, and low sensitivity and specificity, as well as poor agreement, were reported. What is New: • Our study confirms the evidence that routine biopsies from macroscopically normal areas during upper and lower digestive endoscopies can lead to histopathological diagnoses and different medical management. • This is the first research on this topic in a Latin population, from a developing country, reassuring the results obtained in previous papers from other countries.

What should be the treatment for intestinal neuronal dysplasia type B? A comparative long-term follow-up study.

PURPOSE: To present the long-term follow-up outcomes of patients with intestinal neuronal dysplasia type B (IND-B) managed either conservatively or surgically. METHODS: We conducted an ambispective, observational, longitudinal, and comparative study. Clinical data were reviewed at the start of treatment. After a minimum period of five years, the patients participated in semi-structured interviews in which the bowel function score (BFS) was applied to assess intestinal function, a proposed intestinal symptom index (ISI) to assess clinical symptoms, and a classification of clinical prognosis to assess treatment success. Comparisons between the two types of treatment were performed by evaluating pre- and post-treatment criteria. RESULTS: Fifty patients diagnosed with IND-B were included in the study. Thirty-eight patients underwent surgical treatment (26 elective surgical treatment for primary colorectal resection and 12 emergency colostomies for intestinal obstruction or enterocolitis). Twelve patients were managed conservatively. With the exception of the patients who required an emergency operation (n = 12), the two groups were composed of patients with severe constipation who had similar clinical and functional characteristics at the time of IND-B diagnosis. A better clinical response was observed in patients submitted to conservative treatment, with a greater increase in the BFS (16.5 [-4/+18] versus 4 [-15/+17]; p = 0.001), indicating better bowel function and a more pronounced drop in ISI (-6 [-7/-4] versus -4 [-6/+1]; p = 0.015), suggesting fewer symptoms. The percentage of patients who had a successful treatment was higher in the group treated conservatively (72.7% versus 42.3%; p = 0.03). CONCLUSION: Conservative management showed better long-term outcomes than surgical management in children with IND-B.

Ultrastructural analysis of bone formation around dental implants in nondiabetic rats, severe diabetics not controlled and controlled with insulin.

PURPOSE: To evaluate bone formation through ultrastructural analysis around titanium implants in severe alloxanic uncontrolled diabetic rats, and controlled with insulin, in comparison with nondiabetic rats. METHODS: Thirty-six male Wistar rats, weighing between 200 and 300 g, divided into three experimental groups: normal control group (G1), a diabetic group without treatment (G2), and a diabetic group treated with insulin (G3). The animals received titanium implants in the right femur, and osseointegration was evaluated at 7, 14, and 21 days after surgery, through ultrastructural analysis using scanning electron microscopy. RESULTS: The ultrastructural analysis showed a dense bone structure in the G1, few empty spaces and a small number of proteoglycans; G2 presented bone matrix with a loose aspect, irregular arrangement, thin trabeculae, empty spaces and a large number of proteoglycans; G3 obtained similar results to G1, however with a higher number of proteoglycans. CONCLUSION: Severe diabetes caused ultrastructural changes in bone formation, and insulin therapy allowed an improvement in osseointegration, but it was not possible to reach the results obtained in the control group.

Acute aortic wall injury caused by aortic cross-clamping: morphological and biomechanical study of the aorta in a swine model of three aortic surgery approaches.

BACKGROUND: Aortic cross-clamping and balloon occlusion of the aorta could lead to damage to the aorta wall. OBJECTIVE: The aim of this study was to investigate changes to the aorta wall related to the method used to interrupt flow (clamping or balloon) in the different techniques available for aortic surgery. METHODS: Experiments were performed on 40 female pigs, weighing 25-30kg, which were randomly allocated to 4 study groups: S (n=10), no intervention (sham group); C (n=10), midline transperitoneal laparotomy for infrarenal abdominal aortic access with 60 min of cross-clamping; L (n=10), laparoscopic infrarenal abdominal aortic surgery with 60 min of cross-clamping; EV (n=10), remote proximal aortic control with transfemoral arterial insertion of aortic occlusion balloon catheter, inflated to provide continued aortic occlusion for 60min. After euthanasia, the aortas were removed and cross-sectioned to obtain histological specimens for light microscopic and morphometric analyses. The remaining longitudinal segments were stretched to rupture and mechanical parameters were determined. RESULTS: We observed a reduction in the yield point of the abdominal aorta, decrease in stiffness and in failure load in the aortic cross-clamping groups (C and L) compared with the EV group. CONCLUSIONS: Aortic cross-clamping during open or laparoscopic surgery can affect the mechanical properties of the aorta leading to decrease in resistance of the aorta wall, without structural changes in aorta wall histology.

MicroRNA expression profiles in the esophagus of children with caustic stenosis: A pathway towards esophageal cancer?

BACKGROUND: Eighty percent of caustic ingestions occur in children and esophageal neoplasms may develop as a late complication of such injury. The identification of biomarkers is a promising strategy to improve early diagnosis of esophageal cancer or caustic lesions that are at an increased risk of progression. STUDY DESIGN/AIMS: This study aimed at identifying global microRNA (miRNA) expression changes in esophageal mucosa from children with caustic stenosis. The study included 27 biopsy samples from 15 patients. Samples were divided into two groups, according to the time elapsed after injury (N = 15 in Group A, with less than five years of follow-up and N = 12 in Group B, with more than five years of follow-up). miRNA expression profiles were determined in each lesion, compared with normal esophageal tissues from control group. We used the TaqMan Human MicroRNA Arrays (Thermo Fisher) platform. Furthermore, bioinformatic algorithms were used to identify miRNA target genes and biological pathways including miRNAs and their target genes potentially associated with esophageal disease. RESULTS: Thirteen miRNAs were significantly deregulated (9 over- and 4 underexpressed) in patients from Group A. In patients from Group B, two miRNAs were over- and two were underexpressed. Of note, miR-374 and miR-574 were deregulated in Group B patients and have been linked to esophageal tumorigenesis. We identified signal transduction and transcription factor networks with genes strongly related to development and progression of esophageal cancer. CONCLUSION: miRNAs identified here contribute to a better understanding of pathways associated with malignant transformation from caustic stenosis to neoplastic lesions. This study may serve as a basis for validation of miRNAs, including miR-374 and miR-574, as potential biomarkers of early cancer detection.

Lesão aguda da parede arterial provocada pelo método de interrupção temporária de fluxo em diferentes vias de cirurgia aórtica: estudo morfológico e biomecânico da aorta de porcos / Acute aortic wall injury caused by aortic cross-clamping: morphological and biomechanical study of the aorta in a swine model of three aortic surgery approaches

Resumo Contexto O clampeamento aórtico e a oclusão da aorta com balão poderiam levar a lesões na parede aórtica. Objetivo O objetivo deste estudo foi verificar as alterações da parede aórtica relacionadas ao método de interrupção de fluxo (cample ou balão) em diferentes técnicas disponíveis para cirurgia de aorta. Métodos Os experimentos foram realizados em 40 porcos fêmeas pesando de 25-30 kg, alocados para quatro grupos: S (n = 10), nenhuma intervenção (sham); C (n = 10), laparotomia mediana transperitoneal para acesso à aorta abdominal infrarrenal com tempo de clampeamento de 60 minutos; L (n = 10), cirurgia laparoscópica da aorta abdominal infrarrenal com tempo de clampeamento de 60 minutos; EV (n = 10), controle aórtico proximal com inserção de cateter-balão para oclusão aórtica por acesso femoral, inflado a fim de promover oclusão aórtica contínua por 60 minutos. Após a eutanásia, as aortas foram removidas e seccionadas para obtenção de espécimes histológicos destinados a análises morfométricas e por microscopia de luz. Os fragmentos longitudinais restantes foram estirados até a ruptura, e determinaram-se padrões mecânicos. Resultados Observou-se redução do limite de proporcionalidade da aorta abdominal, diminuição da rigidez e da carga de ruptura nos grupos submetidos a campleamento aórtico (C e L) em comparação ao grupo EV. Conclusões O campleamento aórtico durante cirurgia aberta ou laparoscópica pode afetar as propriedades mecânicas da aorta, ocasionando redução de resistência da parede aórtica sem desencadear alterações na estrutura histológica da parede aórtica.

Abstract Background Aortic cross-clamping and balloon occlusion of the aorta could lead to damage to the aorta wall. Objective The aim of this study was to investigate changes to the aorta wall related to the method used to interrupt flow (clamping or balloon) in the different techniques available for aortic surgery. Methods Experiments were performed on 40 female pigs, weighing 25-30kg, which were randomly allocated to 4 study groups: S (n=10), no intervention (sham group); C (n=10), midline transperitoneal laparotomy for infrarenal abdominal aortic access with 60 min of cross-clamping; L (n=10), laparoscopic infrarenal abdominal aortic surgery with 60 min of cross-clamping; EV (n=10), remote proximal aortic control with transfemoral arterial insertion of aortic occlusion balloon catheter, inflated to provide continued aortic occlusion for 60min. After euthanasia, the aortas were removed and cross-sectioned to obtain histological specimens for light microscopic and morphometric analyses. The remaining longitudinal segments were stretched to rupture and mechanical parameters were determined. Results We observed a reduction in the yield point of the abdominal aorta, decrease in stiffness and in failure load in the aortic cross-clamping groups (C and L) compared with the EV group. Conclusions Aortic cross-clamping during open or laparoscopic surgery can affect the mechanical properties of the aorta leading to decrease in resistance of the aorta wall, without structural changes in aorta wall histology.

Long-term follow-up of patients with intestinal neuronal dysplasia type B: Protocol for an observational, ambispective, and comparative study.

Intestinal neuronal dysplasia type B (IND-B) is a pathological entity of the group of gastrointestinal neuromuscular diseases characterized by complex alterations in the enteric nervous system. Patients typically present with intestinal constipation, sometimes complicated by episodes of intestinal obstruction. The 2 therapeutic modalities include conservative clinical treatment and surgical treatment. Nevertheless, the results of the different therapeutic modalities are conflicting, and follow-up studies are scarce and include only a limited number of patients.This is a single-center, ambispective, observational, longitudinal, and comparative follow-up study to compare the results of conservative clinical and surgical treatments in patients with IND-B. Sixty-three patients (<15 years) who received this diagnosis will be included. These patients will be divided into 2 groups according to the type of treatment that they previously received: 29 patients in the surgical treatment group and 34 patients in the conservative treatment group. Previous data will be recovered from the medical records of the study patients, including signs and symptoms present at the time of diagnosis, particularly those related to bowel habits, and treatments undergone. Later, these patients will be invited to participate in a semistructured interview during which aspects related to the long-term functional results of the bowel habit and quality of life will be investigated after a minimum interval of 5 years posttreatment.This project aims to assess the long-term clinical evolution of patients diagnosed with IND-B and compare the results obtained following conservative clinical and surgical treatments.This protocol will provide sufficient data to analyze the long-term clinical outcome obtained through the 2 treatment modalities proposed for patients with IND-B.

Intestinal neuronal dysplasia type B: A still little known diagnosis for organic causes of intestinal chronic constipation.

Intestinal neuronal dysplasia type B (IND-B) is a controversial entity among the gastrointestinal neuromuscular disorders. It may occur alone or associated with other neuropathies, such as Hirschsprung's disease (HD). Chronic constipation is the most common clinical manifestation of patients. IND-B primarily affects young children and mimics HD, but has its own histopathologic features characterized mainly by hyperplasia of the submucosal nerve plexus. Thus, IND-B should be included in the differential diagnoses of organic causes of constipation. In recent years, an increasing number of cases of IND-B in adults have also been described, some presenting severe constipation since childhood and others with the onset of symptoms at adulthood. Despite the intense scientific research in the last decades, there are still knowledge gaps regarding definition, pathogenesis, diagnostic criteria and therapeutic possibilities for IND-B. However, in medical practice, we continue to encounter patients with severe constipation or intestinal obstruction who undergo to diagnostic investigation for HD and their rectal biopsies present hyperganglionosis in the submucosal nerve plexus and other features, consistent with the diagnosis of IND-B. This review critically discusses aspects related to the disease definitions, pathophysiology and genetics, epidemiology distribution, clinical presentation, diagnostic criteria and therapeutic possibilities of this still little-known organic cause of intestinal chronic constipation.

A useful panel for the diagnosis of Hirschsprung disease in rectal biopsies: calretinin immunostaining and acetylcholinesterase histochesmistry.

The pathological evaluation of rectal biopsies for the diagnosis of Hirschsprung disease has been a challenging issue. We analyzed prospectively the usefulness of calretinin immunostaining and acetylcholinesterase (AChE) histochesmistry in rectal biopsies for the diagnosis of Hirschsprung disease. Frozen tissue samples from 43 patients were used for AChE histochemistry and paraffin-embedded sections for calretinin immunohistochemistry and conventional histology (hematoxylin and eosin [H&E]). Activity for AChE, was demonstrated in 13 of 43 cases, and the absence of immunoreactivity for calretinin was observed in 14 of 43 cases. Conventional histology (H&E) did not reveal ganglion cells in 24 of 43 cases. The results on calretinin were in good agreement with AChE according to the κ index (0.946; P<.001) and presented significantly higher specificity (96.7×63.3; P<.002) and accuracy (97.6×74.4; P<.003) when compared with conventional histology (H&E). The final diagnosis of Hirschsprung disease was confirmed in 13 of 43 patients who were submitted to surgical treatment. The results of the present study indicate that calretinin can be a good tool in ruling out the diagnosis of Hirschsprung disease, by showing positive staining in ganglion cells and intrinsic nerve fibers, whereas AChE is useful in confirming the diagnosis of Hirschsprung disease, by revealing activity of this enzyme in hypertrophied nerve fibers. The association between calretinin and AChE can be a useful panel for the histopathologic evaluation of rectal biopsies for the diagnosis of Hirschsprung disease.