The clinical characteristics of colonic pseudo-obstruction and the factors associated with medical treatment response: a study based on a multicenter database in Korea

Acute colonic pseudo-obstruction in polytrauma patients

BACKGROUND

Acute colonic pseudo-obstruction (ACPO) is characterized by severe colonic distension without mechanical obstruction. It has an uncertain pathogenesis and poses diagnostic challenges. This study aimed to explore risk factors and clinical outcomes of ACPO in polytrauma patients and contribute information to the limited literature on this condition.

METHODS

This retrospective study, conducted at a Level 1 trauma center, analyzed data from trauma patients with ACPO admitted between July 2009 and June 2018. A control cohort of major trauma patients was used. Data review encompassed patient demographics, abdominal imaging, injury characteristics, analgesic usage, interventions, complications, and mortality. Statistical analyses, including logistic regression and correlation coefficients, were employed to identify risk factors.

RESULTS

There were 57 cases of ACPO, with an incidence of 1.7 per 1,000 patients, rising to 4.86 in major trauma. Predominantly affecting those older than 50 years (75%) and males (75%), with motor vehicle accidents (50.8%) and falls from height (36.8%) being the commonest mechanisms. Noteworthy associated injuries included retroperitoneal bleeds (RPBs) (37%), spinal fractures (37%), and pelvic fractures (37%). Analysis revealed significant associations between ACPO and shock index >0.9, Injury Severity Score >18, opioid use, RPBs, and pelvic fractures. A cecal diameter of ≥12 cm had a significant association with cecal ischemia or perforation.

CONCLUSION

This study underscores the significance of ACPO in polytrauma patients, demonstrating associations with risk factors and clinical outcomes. Clinicians should maintain a high index of suspicion, particularly in older patients with RPBs, pelvic fractures, and opioid use. Early supportive therapy, vigilant monitoring, and timely interventions are crucial for a favorable outcome. Further research and prospective trials are warranted to validate these findings and enhance understanding of ACPO in trauma patients.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Update on the Diagnosis and Management of Acute Colonic Pseudo-obstruction (ACPO)

PURPOSE OF REVIEW

Acute Colonic Pseudo-obstruction (ACPO) is a cause of large intestinal dilation and obstruction without any physical transition point. It remains difficult to diagnose and treat. We review the recent updates on diagnosis and management of ACPO.

RECENT FINDINGS

Recent guidelines have posited that conservative management can be tried in most cases of ACPO, but that early decompression and surgery should be considered. Use of neostigmine is still a viable option but there is also promising data on pyridostigmine as well as prucalopride. Resolution of ACPO should be followed by daily use of polyethylene glycol (PEG) to help prevent recurrence. ACPO warrants early and accurate diagnosis with exclusion of alternate causes of large bowel dilation. Conservative management can be attempted for 48-72 h in those with cecal diameters < 12 cm and without signs of peritonitis and perforation. Early escalation of management should be attempted with neostigmine followed by endoscopy and/or surgery as needed, given that longer periods of dilation are associated with worse outcomes. There is promising new evidence for use of pyridostigmine and prucalopride, but further trials are needed prior to incorporating them into regular use. Finally, studies are lacking regarding prevention of ACPO after initial resolution.

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.

Acute Colonic Pseudo-Obstruction

Acute colonic pseudo-obstruction (ACPO) is a functional disorder of the large intestine distinguished by colonic dysmotility resulting in colonic distension in the absence of mechanical obstruction. The underlying pathophysiology of ACPO remains unclear despite technological advances in understanding the physiology of colonic motility, such as spatio-temporal mapping and high-resolution manometry. In many ways, the management of ACPO has remained relatively unchanged for 40 years. Patients with perforation or suspected ischemia undergo operative intervention, while patients without undergo initial conservative management with bowel rest, correction of electrolyte disturbances, and mobilization. Patients who fail conservative management or have prominent cecal dilatation undergo decompression with either neostigmine or colonoscopy. A subset of patients with ACPO will have recurrent symptoms despite endoscopic and medical management. For these patients who are difficult to manage, an underlying colonic functional disorder, such as slow-transit dysmotility or chronic intestinal pseudo-obstruction may be considered. The following review of ACPO aims to provide a concise update of the causes, diagnosis, and management of this emergency surgical condition.

American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in the management of acute colonic pseudo-obstruction and colonic volvulus

Colonic volvulus and acute colonic pseudo-obstruction (ACPO) are 2 causes of benign large-bowel obstruction. Colonic volvulus occurs most commonly in the sigmoid colon as a result of bowel twisting along its mesenteric axis. In contrast, the exact pathophysiology of ACPO is poorly understood, with the prevailing hypothesis being altered regulation of colonic function by the autonomic nervous system resulting in colonic distention in the absence of mechanical blockage. Prompt diagnosis and intervention leads to improved outcomes for both diagnoses. Endoscopy may play a role in the evaluation and management of both entities. The purpose of this document from the American Society for Gastrointestinal Endoscopy's Standards of Practice Committee is to provide an update on the evaluation and endoscopic management of sigmoid volvulus and ACPO.

Colonic Pseudo-obstruction With Transition Zone: A Peculiar Eastern Severe Dysmotility

Background/Aims

Previous studies from Korea have described chronic intestinal pseudo-obstruction (CIPO) patients with transition zone (TZ) in the colon. In this study, we evaluated the pathological characteristics and their association with long-term outcomes in Korean colonic pseudo-obstruction (CPO) patients with TZ.

Methods

We enrolled 39 CPO patients who were refractory to medical treatment and underwent colectomy between November 1989 and April 2016 (median age at symptoms onset: 45 [interquartile range, 29–57] years, males 46.2%). The TZ was defined as a colonic segment connecting a proximally dilated and distally non-dilated segment. Detailed pathologic analysis was performed.

Results

Among the 39 patients, 37 (94.9%) presented with TZ and 2 (5.1%) showed no definitive TZ. Median ganglion cell density in the TZ adjusted for the colonic circumference was significantly decreased compared to that in proximal dilated and distal non-dilated segments in TZ (+) patients (9.2 vs 254.3 and 150.5, P < 0.001). Among the TZ (+) patients, 6 showed additional pathologic findings including eosinophilic ganglionitis (n = 2), ulcers with combined cytomegalovirus infection (n = 2), diffuse ischemic changes (n = 1), and heterotropic myenteric plexus (n = 1). During follow-up (median, 61 months), 32 (82.1%) TZ (+) patients recovered without symptom recurrence after surgery. The presence of pathological features other than hypoganglionosis was an independent predictor of symptom recurrence after surgery (P = 0.046).

Conclusions

Hypoganglionosis can be identified in the TZ of most Korean CPO patients. Detection of other pathological features in addition to TZ-associated hypoganglionosis was associated with poor post-operative outcomes.

Secretory diarrhea and hypokalemia associated with colonic pseudo-obstruction: A case study and systematic analysis of the literature

BACKGROUND

Colonic pseudo-obstruction (CPO) is characterized by colonic distention in the absence of mechanical obstruction or toxic megacolon. Concomitant secretory diarrhea (SD) with hypokalemia (SD-CPO) due to gastrointestinal (GI) loss requires further characterization.

AIM

To perform a systematic review of SD-CPO, report a case study, and compare SD-CPO with classical CPO (C-CPO).

METHODS

We performed a search of MEDLINE, EMBASE, Cochrane, and Scopus for reports based on a priori criteria for CPO, SD and GI loss of potassium. An additional case at Mayo Clinic was included.

RESULTS

Nine publications met inclusion criteria, with a total of 14 cases. Six studies had high, three moderate, and our case high methodological quality. Median age was 74 years (66-97), with 2:1 male/female ratio. Kidney disease was present in 6/14 patients. Diarrhea was described as profuse, watery, or viscous in 10 patients. Median serum, stool, and urine potassium concentrations (mmol/L) were 2.4 (range: 1.9-3.1), 137 (100-180), and 17 (8-40), respectively. Maximal diameter of colon and cecum (median) were 10.2 cm and 10.5 cm, respectively. Conservative therapy alone was effective in five out of 14 patients. Median potassium supplementation was 124 mEq/d (40-300). Colonic decompression was effective in three out of six patients; one had a total colectomy; three out of 14 had died. The main differences between SD-CPO and C-CPO were lower responses to treatments: conservative measures (35.7% vs 73.6%, P=.01), neostigmine (17% vs 89.2%, P<.001), and colonic decompression (50% vs 82.4%, P=.02).

CONCLUSION

SD-CPO is a rare phenotype associated with increased fecal potassium and is more difficult to treat than C-CPO.

Giant colonic volvulus due to colonic pseudo-obstruction

Acute colonic pseudo-obstruction (ACPO), also known as Ogilvie's syndrome, is a clinical syndrome characterised by gross dilation of the caecum and right hemicolon, which sometimes extends to the sigmoid colon and rectum in the absence of an anatomic lesion in the intestinal lumen. It is characterised by impaired propulsion of contents of the gastrointestinal tract, which results in a clinical picture of intestinal obstruction. A careful examination of the markedly distended colon can exclude several colonic pathologies, including mechanical obstruction and other causes of toxic megacolon. ACPO can sometimes predispose or mimic colonic volvulus, especially in geriatric patients.