Chronic Megacolon Presenting in Adolescents or Adults: Clinical Manifestations, Diagnosis, and Genetic Associations

Konservative versus chirurgische Therapie beim idiopathischen und sekundären Megakolon oder Megarektum im Erwachsenenalter - eine retrospektive multizentrische Kontrollstudie

BACKGROUND

Idiopathic and secondary megacolon (MC) and megarectum (MR) in adults is associated with persistent bowel dilatation and reduced intestinal motility. Little is known about the optimal treatment of this rare disease. Therefore, we retrospectively analysed long-term data from these patients in 5 community and university hospitals, focusing on conservative versus surgical treatment.

METHODS

Patient records from 7/2004 to 9/2021 were screened for colorectal diseases with severe constipation and persistent megacolon ≥ 9.0 cm and/or megarectum ≥ 6.5 cm. Follow up-data was collected through telephone interviews and written surveys. ClinicalTrialsgov NCT04340856.

RESULTS

Sixty-seven patients with idiopathic (n=10) and secondary (n=57) MC or MR were identified with only 20 of 67 patients (29.9%) correctly diagnosed. Mean/median age was 64/69 (range 18-93) years. Thirty-two patients were treated with laxative regimens, and 35 underwent surgery (colostomy: n=12, segmental resection, or hemicolectomy: n=10, (sub)total colectomy: n= 13) after conservative treatment attempts in 32/35 (91.4%). The mean/median follow-up was 4.2/2.7 (range 0.1-17.0) years. The readmission rate for MC-associated symptoms was significantly higher after conservative treatment than after surgical therapy at 12 (0.84 vs. 0.36 per patient, p=0.036), 24 (1.00 vs. 0.52, p=0.048) and 36 (1.13 vs. 0.58, p=0.047) months, as was the number of patients with persistent laxative dependence (28/32 (87.5%) vs. 19/33 (57.6%); p = 0.007). Therapy-associated adverse events (Clavien-Dindo classification) were documented more often in surgically treated patients (11/35, 31.4%) (p=0.025).

CONCLUSION

Surgical treatment may be considered earlier if idiopathic or secondary MC or MR is correctly diagnosed, and conservative treatment has been attempted.

Adult-onset megacolon with focal hypoganglionosis: A detailed phenotyping and prospective cohort study

BACKGROUND

In this prospective cohort study, we evaluated features of "adult-onset megacolon with focal hypoganglionosis."

METHODS

We assessed the radiologic, endoscopic, and histopathologic phenotyping and treatment outcomes of 29 patients between 2017 and 2020. Data from community controls, consisting of 19,948 adults undergoing health screenings, were analyzed to identify risk factors. Experts reviewed clinical features and pathological specimens according to the London Classification for gastrointestinal neuromuscular pathology.

KEY RESULTS

The median age of the patients with adult-onset megacolon with focal hypoganglionosis at symptom onset was 59 years (range, 32.0-74.9 years), with mean symptom onset only 1 year before diagnosis. All patients had focal stenotic regions with proximal bowel dilatation (mean diameter, 78.8 mm; 95% confidence interval [CI], 72-86). The comparison with community controls showed no obvious risk factors. Ten patients underwent surgery, and all exhibited significant hypoganglionosis: 5.4 myenteric ganglion cells/cm (interquartile range [IQR], 3.7-16.4) in the stenotic regions compared to 278 cells/cm (IQR, 190-338) in the proximal and 95 cells/cm (IQR, 45-213) in the distal colon. Hypoganglionosis was associated with CD3+ T cells along the myenteric plexus. Colectomy was associated with significant symptom improvement compared to medical treatment [change in the Global Bowel Satisfaction score, -5.4 points (surgery) vs. -0.3 points (medical treatment); p < 0.001].

CONCLUSIONS AND INFERENCES

Adult-onset megacolon with focal hypoganglionosis has distinct features characterized by hypoganglionosis due to inflammation. Bowel resection appears to benefit these patients.

Adult patients with allied disorders of Hirschsprung’s disease in emergency department: An 11-year retrospective study

BACKGROUND

In the past years, only a few studies with a limited number of adult patients analyzed clinical features of allied disorders of Hirschsprung’s disease (ADHD), most of which were individual case reports or lacked detailed clinical information. Although many studies have reported patients presenting to the emergency department (ED) with recurrent abdominal symptoms for a number of disorders, there are few data involving ADHD. However, owing to a lack of awareness of the disease, misdiagnoses and mistreatments are common. Severe complications such as perforation, bleeding, malabsorption, and even death in ADHD had been reported by many studies.

AIM

To assist ED clinicians in having a more comprehensive understanding of this disease and making an early suspected diagnosis of ADHD more effectively.

METHODS

We enrolled 53 patients who visited the ED and were eventually diagnosed with ADHD over the past 11 years in our hospital. Their basic information, clinical manifestations, and imaging findings were analyzed. Blood indices were compared between the ADHD and irritable bowel syndrome (IBS) groups.

RESULTS

Adult patients with ADHD had a mean age of 48.8 ± 14.3 years, and 77.4% had been treated before admission. The transverse colon was the most common dilated part (73.6%), and constipation (67.9%) was the most common symptom. ADHD patients can present with uncommon symptoms and false-negative imaging findings. Logistic regression analysis indicated that body mass index (BMI) [odds ratio (OR) = 0.786, P = 0.013], cholinesterase (per 1000 units; OR = 0.693, P = 0.008), and blood chlorine (OR = 0.816, P = 0.022) were determined to be independent related factors between the ADHD and IBS groups. The area under the receiver operating characteristics curve of these three indices combined was 0.812 (P < 0.001).

CONCLUSION

Emergency physicians should be vigilant regarding patients with chronic constipation, abdominal pain, or abdominal distension, and consider the possibility of ADHD despite its rarity. Abdominal computed tomography examination is recommended as a useful tool in the suspected diagnosis of ADHD. BMI, cholinesterase, and blood chlorine have good discriminative abilities between ADHD and IBS. The nutritional status of adult patients with ADHD is worthy of further attention. Surgical treatment for adult patients with ADHD is important and inevitable.

The Classification and Surgical Treatments in Adult Hirschsprung’s Disease: A Retrospective Study

Purpose

To explore the treatments and short-term effects of different types of adult Hirschsprung’s disease.

Methods

89 patients treated in Shanghai Changhai Hospital were retrospectively analyzed. According to the patient’s medical history, clinical manifestations, auxiliary examination and postoperative pathological results, the patients were divided into adult congenital megacolon, adult idiopathic megacolon, ganglion cell deficiency (types I and II), toxic megacolon and iatrogenic megacolon, The Treatment methods and short-term prognosis of patients in each group were summarized.

Results

41 cases of Hirschsprung’s disease in adults and low anterior resection or pull-out low anterior resection was performed, and 35 patients with idiopathic Megacolon were treated with one-stage subtotal colon resection under the condition of adequate preoperative preparation. Some patients admitted for emergency intestinal obstruction received conservative treatment first or underwent elective surgery after colonoscopic decompression was improved; two patients with ganglion cell deficiency subtotal colectomy were performed to remove the dilated proximal bowel segment and the narrow distal bowel segment; three patients with toxic Hirschsprung’s disease underwent colostomy in mild cases, while subtotal colorectal resection was required in severe cases; Iatrogenic megacolon was diagnosed in eight cases and the optimum operation should be selected according to the specific conditions of patients.

Conclusion

Adult Hirschsprung’s diseases were divided into adult congenital hirschsprung’s disease, idiopathic Hirschsprung’s disease, ganglion cell deficiency, toxic hirschsprung’s disease, and iatrogenic Hirschsprung’s disease. Different types of surgical treatments for Hirschsprung’s disease in adults should be selected according to the specific diagnosis. All patients with adult Hirschsprung’s diseases have good short-term outcomes after surgical treatment.

Bowel perforation due to chronic idiopathic megacolon: Case report and literature review

INTRODUCTION AND IMPORTANCE

Chronic idiopathic megacolon is a rare condition characterized by an irreversible distension of the colon in the absence of organic disease. The pathogenesis of this condition is still unclear and the data in literatures are not consistent.

CASE PRESENTATION

We report a case of an 87-years-old woman affected by bowel perforation in chronic idiopathic megacolon. The patient underwent an emergency subtotal colectomy with terminal ileostomy. The postoperative was uneventful. At the histopathological examination, no organic cause of megacolon was found, so a diagnosis of idiopathic megacolon was done.

CLINICAL DISCUSSION

Idiopathic megacolon is difficult to diagnose due to the lack of specific clinical manifestations and pathological features. If not carefully investigated, can lead to severe complications such as perforation of the dilated bowel and subsequent peritonitis and sepsis, metabolic and electrolyte abnormalities. The protocols for management of IMC remains controversial. To achieve a good long-term outcome, early intervention is recommended.

CONCLUSION

Early diagnosis of idiopathic megacolon is needed to perform the best therapeutic strategy and prevent complications, but further studies are needed.

Idiopathic Megacolon-Short Review

INTRODUCTION

Idiopathic megacolon (IM) is a rare condition with a more or less known etiology, which involves management challenges, especially therapeutic, and both gastroenterology and surgery services. With insufficiently drawn out protocols, but with occasionally formidable complications, the condition management can be difficult for any general surgery team, either as a failure of drug therapy (in the context of a known case, initially managed by a gastroenterologist) or as a surgical emergency (in which the diagnostic surprise leads additional difficulties to the tactical decision), when the speed imposed by the severity of the case can lead to inadequate strategies, with possibly critical consequences.

METHOD

With such a motivation, and having available experience limited by the small number of cases (described by all medical teams concerned with this pathology), the revision of the literature with the update of management landmarks from the surgical perspective of the pathology appears as justified by this article.

RESULTS

If the diagnosis of megacolon is made relatively easily by imaging the colorectal dilation (which is associated with initial and/or consecutive clinical aspects), the establishing of the diagnosis of idiopathic megacolon is based in practice almost exclusively on a principle of exclusion, and after evaluating the absence of some known causes that can lead to the occurrence of these anatomic and clinical changes, mimetically, clinically, and paraclinically, with IM (intramural aganglionosis, distal obstructions, intoxications, etc.). If the etiopathogenic theories, based on an increase in the performance of the arsenal of investigations of the disease, have registered a continuous improvement and an increase of objectivity, unfortunately, the curative surgical treatment options still revolve around the same resection techniques. Moreover, the possibility of developing a form of etiopathogenic treatment seems as remote as ever.

PHOX2B Immunostaining: A Simple and Helpful Tool for the Recognition of Ganglionic Cells and Diagnosis of Hirschsprung Disease

Hirschsprung disease (HD) is a congenital disorder of the enteric nervous system that occurs in ∼1 in 5000 live births. It is characterized by the absence of ganglionic cells (GCs) in the distal intestine. The diagnosis relies on the thorough analysis of a rectal suction biopsy (RSB), which must show a complete absence of GCs after careful examination of at least 100 serial sections. Such a negative characteristic explains the difficulty of this diagnosis. Moreover, GCs may be immature in very young or preterm born children, making them hard to recognize. Therefore, ancillary techniques have been developed as diagnostic help, such as acetylcholinesterase histochemistry and calretinin immunostaining. These techniques reveal only indirect clues, focusing mainly on the changes in nerve fibers, but not on GCs themselves. As PHOX2B has been shown to be a very specific transcription factor in GCs and in progenitor enteric nerve cells, we have assessed (i) PHOX2B immunostaining in immature enteric ganglia and (ii) the use of PHOX2B immunostaining for the recognition of GCs on RSBs for suspicion of HD. We have observed PHOX2B expression in all GCs, both mature and immature, and its complete absence in Hirschsprung cases. We suggest that the use of PHOX2B immunostaining is of great help (i) in the recognition of GCs on RSBs regardless of their differentiation and therefore (ii) in the diagnosis of HD.

Refractory Constipation: How to Evaluate and Treat

Patients are often referred for treatment of refractory constipation that may result from uncontrolled underlying disease or ineffective treatment. This article reviews clinical testing in patients with refractory constipation, differentiating subtypes of primary chronic idiopathic constipation, and common pitfalls in assessment of refractory chronic constipation. The constipation may also be refractory because of significant associated diseases affecting the colon and resulting in slow transit constipation. The choice of therapy is best guided by the subtype. Management of refractory constipation requires correct diagnosis and individualized treatment, which may rarely include conservative surgery (loop ileostomy).

Characterization of gut contractility and microbiota in patients with severe chronic constipation

Chronic constipation (CC) is one of the most common gastrointestinal disorders worldwide. Its pathogenesis, however, remains largely unclear. The purpose of the present work was to gain an insight into the role of contractility and microbiota in the etiology of CC. To this end, we studied spontaneous and evoked contractile activity of descending colon segments from patients that have undergone surgery for refractory forms of CC. The juxta-mucosal microbiota of these colon samples were characterized with culture-based and 16S rRNA sequencing techniques. In patients with CC the spontaneous colonic motility remained unchanged compared to the control group without dysfunction of intestinal motility. Moreover, contractions induced by potassium chloride and carbachol were increased in both circular and longitudinal colonic muscle strips, thus indicating preservation of contractile apparatus and increased sensitivity to cholinergic nerve stimulation in the constipated intestine. In the test group, the gut microbiota composition was assessed as being typically human, with four dominant bacterial phyla, namely Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria, as well as usual representation of the most prevalent gut bacterial genera. Yet, significant inter-individual differences were revealed. The phylogenetic diversity of gut microbiota was not affected by age, sex, or colonic anatomy (dolichocolon, megacolon). The abundance of butyrate-producing genera Roseburia, Coprococcus, and Faecalibacterium was low, whereas conventional probiotic genera Lactobacillus and Bifidobacteria were not decreased in the gut microbiomes of the constipated patients. As evidenced by our study, specific microbial biomarkers for constipation state are absent. The results point to a probable role played by the overall gut microbiota at the functional level. To our knowledge, this is the first comprehensive characterization of CC pathogenesis, finding lack of disruption of motor activity of colonic smooth muscle cells and insufficiency of particular members of gut microbiota usually implicated in CC.

Distinctive genetic variation of long-segment Hirschsprung's disease in Taiwan

BACKGROUND

Hirschsprung's disease (HSCR) is a congenital disorder with the absence of myenteric and submucosal ganglion cells within distal gut. Due to multigenic inheritance and interactions, we employed next-generation sequencing (NGS) to investigate genetic backgrounds of long-segment HSCR (L-HSCR) in Taiwan.

METHODS

Genomic DNA extracted from peripheral blood of L-HSCR patients was subjected to capture-based NGS, based on a 31-gene panel. The variants with allele frequency <0.05 and predicted by computational methods as deleterious were further validated by Sanger sequencing in patients and their family as well to tell de novo from inherited variants.

RESULTS

Between 2015/04 and 2018/05, this study enrolled 23 L-HSCR patients, including 15 (65.2%) sporadic cases and 8 (34.8%) familial patients in 4 different families. Six sporadic and seven familial cases showed possible harmful variants across eight different genes, accounting for an overall detection rate of 56.5%. These variants mainly resided in SEMA3C, followed by RET, NRG1, and NTRK1. Three sporadic and 2 familial cases exhibited strong pathogenic variants as a deletional frameshift or stop codon in RET, L1CAM or NRG1. In a HSCR family, the father passed on a pathogenic RET frameshift to two daughters; however, only one developed HSCR.

CONCLUSION

Using NGS, we disclosed deleterious mutations such as a frameshift or stop codon in either familial or sporadic patients. Our cases with isolated L-HSCR or even total colonic aganglionosis appeared to exhibit complex patterns of inheritance and incomplete penetrance even in families with the same genetic variants, reflecting the possible effects of environmental factors and genetic modifiers.