June 2021

Synopsis: Colonic diverticulitis is the third most common cause of hospitalization due to gastrointestinal illness and the leading cause of elective colon resection in the United States. The severity of a diverticulitis episode can range broadly from minimal left lower quadrant tenderness and GI distress to life threatening acute colonic perforation requiring emergency surgical intervention, although the latter scenario is quite rare. Previous guidelines recommended elective resection following the second episode of diverticulitis, or following the first episode in young individuals, but given the rarity of life-threatening complications secondary to diverticulitis and the not insignificant potential complications related to colon resection, the decision for resection versus conservative management is now tailored to patient preferences rather than a set number of diverticulitis episodes. Additionally, the current paradigm of colon resection following any episode of complicated diverticulitis has been challenged by some for the same cited reasons. However, deferment of elective sigmoid resection may result in recurrent episodes of diverticulitis, whereas this could be prevented, and potentially improve quality of life, if elective sigmoid resection were to be pursued. The authors conducted the Laparoscopic Elective Sigmoid Resection Following Diverticulitis (LASER) to study the effect of elective sigmoid resection on quality of life for patients with a history of recurrent or complicated diverticulitis.

Patients were randomized to either undergo elective laparoscopic sigmoid resection or conservative management. Patients were included if they had ≥3 episodes of diverticulitis in a 2-year period, if they had 1 episode of complicated, conservatively treated diverticulitis, or ≥3 months of pain/bowel disturbances following an episode of acute diverticulitis. The primary outcome trial outcome was the difference in Gastrointestinal Quality of Life Index (GIQLI) score at randomization and at 6 months post randomization. 

A total of 85 patients were randomized and included in the intention to treat analysis, 41 of whom underwent elective sigmoid resection, and 44 of whom underwent conservative management. The majority of patients within the trial met inclusion criteria due to recurrent diverticulitis (78%). Among those who underwent surgery, 2 patients suffered anastomotic leaks requiring emergent surgical intervention, and 2 patients developed post-operative abscesses requiring draining, resulting in a 10% complication rate following elective laparoscopic sigmoid resection. Of the 72 patients who answered both the baseline and 6-month GIQLI questions, the difference between initial and 6-month scores was a mean of 11.96 points higher in the surgical group compared with the conservative treatment group (mean [SD] of 11.96 [15.89] points vs −0.2 [19.07] points; difference, 11.96; 95% CI, 3.72-20.19; P =0.005), indicating that quality of life significantly improved following surgery compared to conservative management. Twelve patients in the conservative treatment group developed recurrent diverticulitis, while 2 patients in the surgical group developed recurrent diverticulitis. None of these patients required emergency surgery. At 6 months post-randomization, the conservatively treated group reported abdominal pain more often than did the surgical group. 

Based on the findings of this study, elective laparoscopic sigmoid resection for patients with recurrent, complicated or persistently painful diverticulitis may improve patients’ quality of life compared to conservative therapy; however, it does carry with it a 10% risk of complications requiring procedural intervention. These results can be used to provide additional information regarding surgery versus conservative management for patients considering their treatment options for recurrent or complicated diverticulitis.  

Synopsis: To develop evidence-based guidelines for tracheostomy decannulation, this randomized, unblinded trial compared the difference in time to decannulation between patients who were deemed appropriate for removal based on their suctioning requirement (intervention) vs. capping trials (control).

330 ICU patients in 5 Spanish hospitals were enrolled, 169 in suctioning group (intervention) and 161 in capping group (control), and compared with intention-to-treat analysis. The primary data point was time from ventilator liberation to tracheostomy removal. Both groups followed the same aggressive ventilation weaning protocol with twice daily spontaneous breathing trials (SBT). Successful wean was defined as SBT for more than 12 hours on 2 consecutive days and these patients were then eligible for decannulation trials. Patients in the suctioning cohort were ready for decannulation if they required less than or equal to two suctions every 8 hours over a 24 hour period. Patients in the capping group were ready for decannulation if they could maintain 24 hours without uncapping. Importantly, patients in the suctioning cohort received continuous 60 LPM high-flow oxygen, and capping patients received oxygen only when uncapped. 

Ultimately, patients who were decannulated based off of their suctioning requirement had a faster time to removal than capping (6 days vs. 13 days, 95% CI 5-9), lower incidence of weaning failure (7% vs 17%, CI 3.4-17.4), shorter total hospital length of stay (48 days vs. 62 days, CI 9-33), and lower (though not significant) incidence of pneumonia (4% vs. 10%, CI 0.2-11.8) and tracheobronchitis (19% vs 29%, CI 1.0-19.3). There was no difference in the rate of recannulation. 

The authors suggest that patients fared better when using suctioning as a primary metric because the metabolic demands of capping trials result in a propensity to develop respiratory infections and other complications, lengthening hospital stay. A major limitation to this study is the inability to blind the ICU teams to the treatment arm and therefore inherent bias may exist in determining readiness for decannulation. Additionally, patients in the intervention arm received high flow oxygen throughout their trial, which provides some minimal positive pressure as well as improved mucociliary transport, thereby possibly reducing the need for suctioning. When compared to our standard practices, this study may not be directly applicable because 1) every patient in the study had the same tracheostomy without exchanging or downsizing and 2) twice daily SBTs were performed which may be more aggressive than our standard ICU algorithms. 

This study suggests that in conscious ICU patients without concerns for airway compromise, a 24 hour capping trial is likely an unnecessary burden and prolongs time to decannulation and discharge. The impact of the unblinded nature, different definitions of decannulation preparedness, and continuous vs. intermittent high-flow oxygen all warrant further investigation. 

Synopsis: Hirschsprung disease (HD) is a congenital enteric disorder that involves disordered caudal migration of neural crest cells, resulting in a lack of innervation to the affected intestine. The transition from ganglionic to aganglionic cells typically occurs in the rectosigmoid colon, but a significant portion of patients have more proximal agangiolosis as well, which may involve proximal colon, the entire colon, or even portions of the small bowel. Cases with more extensive involvement are typically classified as long-segment HD (LSHD) and are clinically differentiated from classic rectosigmoid short segment HD (SSHD). While SSHD is well characterized, LSHD variably defined, there is no consensus on optimal surgical approach, and reporting of long-term outcomes has been inconsistent. Recognizing these limitations in the current literature, the American Pediatric Surgical Association set out to perform a systematic literature review to answer the following questions: what is the definition of LSHD and how is it best determined, what is the preferred method for surgical repair of LSHD, what are the long-term outcomes for patients with LSHD, and what future strategies are being developed for the treatment of LSHD. The authors identified sixty-six records that addressed at least one of the pre-defined questions. Regarding the first two questions, they emphasized standardized nomenclature to assist in comparisons across studies and the importance of leveling biopsies to determine the precise transition point prior to anorectal dissection.

Regarding surgical approach, the authors identified 24 articles that addressed operative technique and outcome for LSHD and TCHD. Patients typically underwent an initial diverting colostomy with leveling biopsies, followed by either a complete resection of the aganglionic bowel and end-to-end anastomosis of normal bowel to the remaining rectum (Swenson, Soave) or a retro-rectal side to side anastomosis of normal bowel to anganglionic rectum (Duhamel, Martin). Other procedures include an ileoanal anastomosis with a pouch (IPAA), colectomy with straight ileoanal pull-through (AIPT), permanent ileostomy/colostomy, and intestinal transplantation. While there was insufficient evidence to definitively recommend one operation for LSHD, the authors noted multiple case series describing positive outcomes with the Duhamel for its relative ease in terms of surgical technique and good long-term functionality. In particular, the authors noted a retrospective study of 260 cases comparing Duhamel to Soave and Swenson procedures that concluded long term continence and function were better with Duhamel in all lengths of aganglionosis. Additionally, in a series of 48 TCHD patients, the average number of additional surgical procedures was 3.7 following a Soave, 1.4 after a Martin, and 1.0 after a Duhamel. Prospective studies will be needed to definitively demonstrate the superiority of a particular technique and to determine the appropriate timing of colostomy reversal.

A. Normal pre-op anatomy. B. Swenson procedure, in which the aganglionic segment of bowel is completely resected and anastomosed to the remaining rectum. C. Duhamel procedure, in which a segment of aganglionic bowel is anastomosed to normal bowel that is brought through in a retrorectal position. In the Martin modification, the remaining aganglionic colon extends to the entire left colon, D. Soave procedure, in which the aganglionic segment of bowel is resected and anastomosed to distal rectum with a surrounding cuff of muscle that is developed by removing a segment of mucosa and submucosa. 

Long-term outcomes varied significantly between studies. The authors emphasized that patients with LSHD and TCHD should be followed long-term as a significant percentage of patients continue to have difficulty with soiling and incontinence, though both generally improve over time. Multiple studies particularly emphasize that patients with LSHD and TCHD have high rates of Hirschsprung associated enterocolitis (HAEC). HAEC is an inflammatory disorder in which patients can develop fever, abdominal distension, bloody bowel movements, and shock. Importantly, it can develop both before and after operative repair. 

The article further reviewed treatment strategies under development and particularly focused on stem cell therapies for LSHD. Recent studies have demonstrated both endogenous and pluripotent stem-cell derived ENS progenitor transplantation into mice with excellent safety profiles. Additionally, multiple groups are investigating the use of scaffolds, which consist of naturally derived decellularized matrices that preserve extracellular matrix composition and native tissue architecture for intestinal replacement. These therapies are currently limited to pre-clinical models, but hold promise for establishing innervation to aganglionated bowel and restoring intestinal function. 

Bottom line: Long segment Hirschsprung disease is a difficulty clinical entity that is inconsistently defined in the literature and lacks prospective studies to adequately compare methods of treatment. Uniform definitions and precise anatomic descriptions are needed for proper comparisons and a prospective multi-institution study will be necessary to better guide surgeons in their operative approach. Stem cell therapy appears to be a promising approach in restoring intestinal function.