The manometric evaluation of the rectosphincteric reflex in total colonic aganglionosis

Total colonic aganglionosis and Hirschsprung's disease: a review

Total colonic aganglionosis is a relatively uncommon form of Hirschsprung's disease (HSCR). It occurs in approximately 2-13 % of HSCR cases and involves the entire colon which is aganglionic but may extend proximally into varying lengths of small bowel. As a result, it should be separated into Total colonic aganglionosis (TCA) [defined as aganglionosis extending from the anus to at least the ileocaecal valve but no more than 50 cm small bowel proximal to the ileocaecal valve] and total colonic and small bowel aganglionosis (TCSA) which may involve very long segments of small bowel aganglionosis. Clinically, TCA appears to represent a different spectrum of disease in terms of presentation and difficulties which may be experienced in diagnosis suggesting a different pathophysiology from the more common forms of HSCR. It is therefore not yet clear whether TCA merely represents a long form of HSCR or a different expression of the disease. A number of differences exist between TCA and other forms of HSCR which require explanation if its ubiquitous clinical features are to be understood. In addition to the usual explanations for the aganglionosis of HSCR, there is some evidence suggesting that in place of being purely congenital, it may represent certain different pathophysiologic mechanisms, some of which may continue to be active after birth. This study reviews what is known about the clinical, radiological and histopathologic differences between TCA and the more frequently encountered recto-sigmoid (or short-segment; S-HSCR) and correlates them with what is currently known about the genetic and molecular biologic background to find possible pathogenetic mechanisms.

A new diagnostic scoring system to differentiate Hirschsprung's disease from Hirschsprung's disease-allied disorders in patients with suspected intestinal dysganglionosis

PURPOSE

To create a simple diagnostic scoring system to differentiate Hirschsprung's disease (HD) from Hirschsprung's disease-allied disorders (HAD) in patients with suspected intestinal dysganglionosis (IDs).

METHODS

Between 1998 and 2008, 967 patients with suspected intestinal dysganglionosis underwent surgical treatment at the pediatric surgery department of Tongji Hospital. The diagnosis of HD or HAD was confirmed by postoperative pathological examination. All patients underwent preoperative work-up including barium enema, anorectal manometry, and histochemical acetylcholinesterase staining of rectal mucosa. Known risk factors for IDs were recorded. The predicting score was calculated by summing the scores of the risk factors and three preoperative tests. The sensitivity, specificity, accuracy, positive predictive values, negative predictive values, positive likelihood ratios, and negative likelihood ratios of the predicting score were calculated. The cutoff score for predicting HD was determined using receiver operating characteristic (ROC) analysis. The accuracy of the predicting score was measured by the area under the ROC curve.

RESULTS

Failed or delayed passage of meconium, age <3 years and male gender were risk factors associated with HD. The area under the ROC curve of the predicting score was 0.927 (95 % confidence interval, 0.910-0.944). A predicting score of more than 5 was used as a cutoff for predicting HD. The scoring system achieved 83.1 % sensitivity, 89.5 % specificity, and 85.9 % accuracy in predicting HD.

CONCLUSION

Patients with a predicting score of more than 5 are more likely to be diagnosed with HD, whereas a score less than 5 are mostly indicative of HAD.

Total colonic aganglionosis in Hirschsprung disease

Total colonic aganglionosis (TCA) is a relatively uncommon form of Hirschsprung disease (HSCR), occurring in approximately 2%-13% of cases. It can probably be classified as TCA (defined as aganglionosis extending from the anus to at least the ileocecal valve, but not >50 cm proximal to the ileocecal valve) and total colonic and small bowel aganglionosis, which may involve a very long segment of aganglionosis. It is not yet clear whether TCA merely represents a long form of HSCR or a different expression of the disease. There are many differences between TCA and other forms of HSCR, which require explanation if its ubiquitous clinical features are to be understood. Clinically, TCA appears to represent a different spectrum of disease in terms of presentation and difficulties that may be experienced in diagnosis, suggesting a different pathophysiology from the more common forms of HSCR. There is also some evidence suggesting that instead of being purely congenital, it may represent certain different pathophysiologic mechanisms. This study, in addition to reviewing current understanding and differences between TCA and the more frequently encountered rectosigmoid (or short-segment) expression, correlates them with what is currently known about the genetic and molecular biological background. Moreover, it reviews current outcomes to find consensus on management.

Clinical and genetic differences in total colonic aganglionosis in Hirschsprung's disease

Although apparently the same condition as Hirschsprung's disease (HSCR), total colonic aganglionosis (TCA) patients (2%-14% congenital aganglionosis) display clinical, histopathologic, and genetic differences that may account for altered clinical presentations.

PATIENTS AND METHODS

Clinical, radiologic, and histologic features of 22 TCA patients of 114 HSCR cases (including 16 kindreds) were retrospectively evaluated by chart review. With ethical permission, DNA mutation analysis of the RET and EDNRB genes was carried out. Polymerase Chain Reaction (PCR) products were screened for genetic variation of by Hetroduplex Single Strand conformation polymorphism (HEX/SSCP) analysis and compared with 60 normal population control samples (20/ethnic groups). The SSCP variants were validated with automated sequencing techniques showing conformational variants in acrylamide gel.

RESULTS

Of the 22 patients, 12 (55%) presented within the first 28 days of extrauterine life, but 10 presented later with 3 (14%) presenting more than 6 months of age. The TCA patients evaluated differed clinically, radiologically, and histologically, and misdiagnosis occurred in 23% (5/22). Seven patients (32%) were familial-the remainder being nonrelated. Histologic features varied, and difficulties in diagnosis occurred in 5 (24%), with unclear histologic condition delaying diagnosis in one and a mistaken aganglionic level, requiring repeat surgery in two. RET variations were detected in 82% (18/22)of TCA as opposed to 33% short segment (S-HSCR) with multiple genetic RET variations in 5 (28%). Genetic variations included exon 2 SNPs but less than in S-HSCR. One had an isolated RET A4 variation with no other abnormalities. Intronic RET variations occurred in intron 6 (2 patients) (IVS6+56delG) and intron 16 (2 patients) (IVS16-38delG). A cysteine radical mutation (C620R) (2 patients) was related to Multiple Endocrine Neoplasia Type 2 (MEN2) in the family. In contrast to S-HSCR, genetic variations in TCA aggregated to the important tyrosine kinase (intracellular) region in 5 patients suggesting a possible pathogenetic link. EDNRB variations occurred in 7 patients (32%) all within exon 4 of the gene.

CONCLUSIONS

Total colonic aganglionosis differs clinically from other HSCR phenotypes and may lead to misdiagnosis. Potential disease-related RET gene mutations include exon 17-21 genetic variations that suggest the possibility of disrupted downstream signaling pathways from vital gene recruitment sites as possible TCA contributing factors.

Total colonic aganglionosis and Hirschsprung's disease: shades of the same or different?

Total colonic aganglionosis is a relatively uncommon form of Hirschsprung's disease (HSCR) occurring in approximately 2-13% of cases. It can probably be divided into total colonic aganglionosis (TCA; defined as aganglionosis extending from the anus to at least the ileocaecal valve, but no more than 50 cm proximal to the ileocaecal valve) and total colonic and small bowel aganglionosis, which may involve a very long segment of aganglionosis. Clinically, they appear to represent a different spectrum of disease in terms of presentation and difficulties in diagnosis which may be experienced, suggesting a different pathophysiology from the more common forms of HSCR. It is not yet clear whether TCA merely represents a long form of HSCR or a different expression of the disease. There are a number of differences between TCA and other forms of HSCR, which require an explanation if its ubiquitous clinical features are to be understood. There is some evidence suggesting that instead of being purely congenital, it may represent certain different pathophysiologic mechanisms, some of which may continue to be active after birth. This study reviews all that is known about the clinical, radiological and histopathologic differences between TCA and the more frequently encountered recto-sigmoid (or short-segment) and correlates them with what is currently known about the genetic and molecular biologic background to find possible pathogenetic mechanisms.

Internal anal sphincter: advances and insights

The internal anal sphincter, the smooth muscle component of the anal sphincter complex, has an ambiguous role in maintaining anal continence. Despite its significant contribution to resting anal canal pressures, even total division of the internal anal sphincter in surgery for anal fistulas may fail to compromise continence in otherwise healthy subjects. However, recently reported abnormalities of the innervation and reflex response of the internal anal sphincter in patients with fecal incontinence indicate its significance in maintaining continence. The advent of sphincter-saving surgery and restorative proctocolectomy has re-emphasized the major contribution of the internal anal sphincter to resting pressure and its significance in preventing fecal leakage. The variable effect of rectal excision on rectoanal inhibitory reflex has led to a reappraisal of the significance of this reflex in discrimination of rectal contents and its impact on anal continence. Electromyographic, manometric, and ultrasonographic evaluation of the internal anal sphincter has provided new insights into its pathophysiology. This article reviews advances in our understanding of internal anal sphincter physiology in health and disease.

Total colonic aganglionosis

The authors describe the genetic, pathophysiology, diagnostic, and therapeutic aspects of total colonic aganglionosis and of aganglionosis extending to the small intestine. The pathogenesis of this disease is genetically determined and is related to the differentiation and migration of cells derived from neural crests. The clinical and radiological features can be useful in the diagnosis but they are not pathognomonic. The histochemical estimation of acetylcholinesterase activity in suction rectal biopsies is useful in establishing the diagnosis; however, the specimens should be examined by an experienced pathologist. The definitive diagnosis of either condition is obtained by performing intraoperative seromuscular biopsies of the rectum, colon, and ileum. From the therapeutic point of view, many surgical techniques have been proposed for the radical treatment of this disease. Some of the techniques have been derived from operations proposed for the treatment of classic Hirschsprung's disease; others have been specifically designed.

Diagnosis of Hirschsprung's disease by anorectal manometry

Anorectal manometry was performed in 48 Japanese children with Hirschsprung's disease and 61 normal children. The resting pressure of the rectum and anal canal was not significantly different between these groups of subjects. The frequency of rhythmical contractions of the anal canal of patients was significantly lower than for the normal subjects, but the frequencies overlapped considerably. Therefore, the frequency is an inadequate indicator for identifying these patients. Conventional manometry elicited a distinct rectoanal relaxation reflex from 90% of the normal children, and the rate increased to 98% when indistinct reflexes were regarded as positive. Indistinct reflexes often occur in neonates, possibly because the constriction of the anal canal is weak. However, when prostaglandin F2 alpha was intravenously administered during the examination, all ambiguous reflexes became distinct. Of patients with Hirschsprung's disease, 4% had a distinct reflex and 19% an atypical one. Most of the atypical reflexes were regarded as being artifacts and were mostly attributed to distension by a balloon. In these patients, the reflex was abolished in case of examination with electric stimulation or stimulation with cold water, procedures which do not dilate the rectum. Moreover these atypical reflexes did not fit the criteria for the normal rectoanal relaxation reflex prepared by the Japan Study Group of Pediatric Intestinal Manometry. The use of electric stimulation, cold water, or intravenously administered prostaglandin F2 alpha improves reliability of the conventional anorectal manometry. A clear and accurate definition of the normal reflex should aid in excluding the atypical reflex.

Total colonic aganglionosis with or without small bowel involvement: an analysis of 137 patients

A total of 137 patients with total colonic aganglionosis involving or not involving the small intestine (TCSA) were analyzed to clarify the recent trends of TCSA in Japan. The percent of TCSA out of all types of Hirschsprung's disease was 8.4%. Male to female ratio in TCSA was 1.5:1. Open biopsy was relatively frequent for diagnosis, the rate being 40.9%. A total of 67.4% of the TCSA patients were diagnosed in the first month of life. Seventy-two percent of the patients underwent enterostomy in the neonatal period. Definitive operations were performed in 67 patients. Sixty underwent retrorectal transanal pull-through, most of which were Martin's procedure (56 cases). Mortality rate after Martin's procedure was 12.5%. Sixty-four percent of the patients with enterostomy alone did not survive. This study shows the recent trends of TCSA and indicates there is still much room for improvement in the clinical management of TCSA.

Total colonic aganglionosis (with or without ileal involvement): a review of 27 cases

From 1960 to 1984, 27 cases of total colonic aganglionosis were treated at the Sick Children's Hospital in Paris; in 19 cases there was ileal involvement, 16 of them extending more than 15 cm above the ileocecal valve. Five had a family history of Hirschsprung's disease. Nine infants died without having had definitive surgery, because of delayed diagnosis, or intractable malabsorption in extensive ileal aganglionosis. Two cases were diagnosed only at the ages of 6 and 13 years. Eleven children had Martin's modification of the Duhamel operation, the oldest of these being now 13 years old; and one girl aged 13 underwent a Swenson operation with ileoanal anastomosis, and one child has had a Kimura procedure. Four infants still have a diverting ileostomy. One out of the 14 operated children died 3 years after operation with fulminating enterocolitis. Late surgical nutritional results are analyzed with regard to the length of the side-to-side ileocolorectal anastomosis, and to the size of the ileorectal anastomosis, on which adequate pouch emptying depends. The essential problem in total colonic aganglionosis is not the surgical management of the condition, but rather its prompt diagnosis and the handling of the neonatal intestinal obstruction.

Induction of the rectoanal reflex by electric stimulation. A diagnostic aid for Hirschsprung's disease

We induced the rectoanal reflex electrically in three groups of children, following rectal dilatation with a balloon. In normal children, and in children with constipation or ileus due to causes other than Hirschsprung's disease, the rectoanal reflex was induced by electric stimulation as well as by dilatation of the rectum with a balloon. In children with Hirschsprung's disease, however, no typical reflex was obtained by either of these stimuli. Since electric stimulation does not dilate the rectum, passive dilatation of the anus or shift of the probe along with balloon expansion does not take place, so no false-positive reflex is elicited. Electric current, moreover, is capable of providing a constant quantifiable stimulus. We have demonstrated the induction of the rectoanal reflex by electric stimulation alone; distention of the circular muscle of the rectum does not appear necessary for the induction of this reflex.