Surgical Management of Recurrent Uncomplicated Diverticulitis

Abstract

Sigmoid diverticulitis represents a most common gastroenterological diagnosis in the western world. There has been a significant change in the management of recurrent uncomplicated diverticulitis in the last 10 to 15 years. The absolute number of previous episodes is not used as criteria to recommend surgery anymore. Young age is no longer considered to be an indication for more aggressive surgical treatment. It is accepted that subsequent episodes of diverticulitis are not significantly worse than the first episode. Laparoscopic surgery is now the standard of care for elective surgery for diverticulitis where expertise is available. There is a consensus that decision to perform sigmoid colectomy should be individualized, after careful risk benefit assessment.

Colonic diverticular disease is one of the most common gastrointestinal diseases in the western world, affecting more than half of population over 60 years. ^{1 2 3} Approximately 25% of them will progress to diverticulitis in their lifetime. ^{2 4} Acute diverticulitis is a significant and growing problem within the United States, accounting for over 160,000 hospitalizations per year and 875,000 days of inpatient care. ⁵ Patients with diverticulitis can be broadly divided into those with complicated diverticulitis (defined as diverticulitis associated with massive free air, abscess, fistula, or stricture) and those with uncomplicated diverticulitis (defined as colonic inflammation without perforation, abscess, fistula, or stricture). Patients presenting with peritonitis, secondary to diverticulitis, often require emergency surgery and bear a significant risk of needing a colostomy to manage intraabdominal sepsis. Complicated diverticulitis can be treated with surgical resection, either emergent or elective; however, experience is growing with nonoperative management after episodes of complicated disease, especially diverticular abscesses. ⁶ Initially, uncomplicated episodes of diverticulitis are usually treated medically with antibiotics. Patients who have one episode and have no recurrence are usually not offered surgery. Patients who have multiple recurrences represent a challenge as the indications to proceed with surgical intervention are nebulous and patients do have to undertake the risk associated with a major surgical intervention. In this chapter, we focus on management of this subset of patients.

Medical Management of Uncomplicated Diverticulitis

Episodes of simple uncomplicated diverticulitis in patients without significant comorbidities can be treated as an outpatient with oral antibiotics. ⁷ Two recent randomized controlled trials from Europe (AVOD in 2012, DIABOLO in 2017) showed observation without antibiotics for simple uncomplicated disease in patients without systemic signs or comorbidities were not inferior to treatment with antibiotics. ^{3 8 9 10} The practice patterns in Europe are quite different from the United States and thus the results from both these trials must be interpreted with caution. In the AVOD study, patients with noncomplicated diverticulitis who did not get antibiotics were admitted to the hospital and received parenteral hydration. In the DIABOLO trial, approximately 33% patients of the cohort evaluated for the trial were not found to be candidates for the trial. Exclusion of such a large number of patients makes the results of the study less generalizable. The published guidelines of the American Society of Colon and Rectum Surgeons (ASCRS) recommend antibiotics as the treatment for uncomplicated diverticulitis and it is the current standard of care in the United States.

Patients with uncomplicated diverticulitis who have severe pain, fevers, leukocytosis, inability to maintain oral intake, or failed outpatient treatment may require inpatient treatment. In addition to the above factors, the authors have a low threshold for admitting patients who have significant comorbidities, are immunosuppressed or elderly. In the United States, such patients are usually admitted for intravenous antibiotics. Patients with uncomplicated diverticulitis usually do not need operation during the index episode. ¹¹

Incidence of Recurrence after Successful Medical Management

It is very difficult to accurately characterize the risk of recurrent diverticulitis after successful medical management of an initial episode. Challenges to arriving at a clear estimate include the lack of an consensus definition of “successful medical management,” differing practice patterns in terms of antibiotics used and duration of treatment, and inability to assess patient compliance during outpatient treatment. Clearly, there is overlap between the symptoms of diverticulitis and other conditions of the colon (inflammatory bowel disease and irritable bowel syndrome), making the latter types of studies difficult to interpret. ¹²

The risk of recurrence following an episode of acute diverticulitis is estimated to be 13 to 47% ² In a large study of approximately, 25,000 patients, 19% had recurrent disease after initial nonoperative management. ³ Broderick-Villa et al ¹³ reported on 2,366 of 3,165 patients (75%) hospitalized with acute diverticulitis and treated nonoperatively in the Kaiser Permanente system. Eighty-six percent of those patients required no further inpatient care for diverticulitis over the 8.9 years of follow-up. Recurrence occurred in only 13.3%of patients and only 3.9% had a second recurrence. No patient with a second recurrence required an operation, and repeat recurrences plateaued after four episodes

Binda et al ¹⁴ obtained complete follow-up for 320 patients treated with antibiotics in 17 Italian hospitals after admission for acute diverticulitis. Over a mean period of 10.7 years, 61% of patients required no further inpatient care. Twenty-two percent of patients had persistent or recurrent symptoms requiring hospitalization, and 17% had a recurrent episode resulting in an emergency operation. The authors noted that unlike other studies of recurrence, episodes were not clustered into the first 2 years or even the first 5 years following the index diagnosis.

Indications for Surgical Management

In the past, a common practice was to offer any patient with three episodes of recurrent diverticulitis surgical resection. In younger patients (age less than 40 or 50 years), this threshold was lower and resection after two recurrent episodes was recommended. The rationale of this recommendation was to prevent morbidity from future recurrent episodes and to prevent emergent operations with colostomy.

Resection based on number of episodes has been challenged, as it was realized that majority of emergency operations are done during the first episode of diverticulitis. ^{7 9} Large prospective studies have shown that the risk of complicated recurrence is low. ^{3 15} In the study by Anaya and Flum, only 18% of patients with recurrent diverticulitis underwent emergent colectomy/colostomy. ³ The rate of emergency Hartmann's procedure in patients with recurrent sigmoid diverticulitis does not appear to exceed the rate of anastomotic leakage after elective sigmoid colectomy. ² Also, performing elective colectomy does not seem to decrease the burden of diverticulitis in population. Simianu and Flum also reported that despite three-fold increase of colectomy rates between 1987 and 2012 in Washington state, the rates of emergency surgery, percutaneous interventions, and emergency admissions for diverticulitis did not decrease. ¹¹

Based on the recent literature, ASCRS now recommends that elective sigmoid resection after recovery from uncomplicated episodes should be individualized. ¹⁶ Risk-benefit ratio should be analyzed and factors, such as inability to exclude carcinoma and effect on lifestyle, should be considered while making a decision. ¹⁶ Quality of life can be impacted by recurrent symptoms and concerns about loss of productivity. ¹⁰ Patients, who are immunosuppressed, have collagen-vascular diseases, or chronic renal failure have a higher risk of diverticular perforation and should be considered for resection after treatment of an uncomplicated episode. ^{17 18}

Smoldering Diverticulitis

In a subset of patients who present with diverticulitis, symptoms do not resolve completely over the course of several months. This entity is sometimes referred to as chronic or smoldering diverticulitis. In this subgroup, the symptoms of pain and evidence of inflammation do not resolve with the antibiotic regimen, or there is an apparent recurrence on cessation of antibiotics. These patients may benefit from colectomy; however, careful consideration should be given to rule out other intra-abdominal conditions such as irritable bowel syndrome (IBS). ¹⁹

Role of Endoscopy

ASCRS practice parameters recommend endoscopic evaluation of the colon to confirm the diagnosis after resolution of an episode of acute diverticulitis, if not done recently. ¹⁶ This recommendation remains controversial. Malignant neoplasms are detected in a very small proportion of patients with presumed diverticulitis. ^{20 21 22 23} However, patients who have other indications, regardless of diverticulitis, should be evaluated endoscopically. ²⁴ The authors perform endoscopic evaluation of the colon after an episode of uncomplicated diverticulitis for patients who have not had a normal colonoscopy in the past 2 years.

Operative Therapy

Timing of Resection

It is standard practice to wait for 6 to 8 weeks after an episode of diverticulitis to perform an elective colectomy. Resections performed after 6 to 8 weeks, when likely the inflammation in the colon has subsided, appear to have lower rates of anastomotic leakage, wound infection, and conversions to open surgery. ²⁵

Preoperative Bowel Preparation

Routine oral mechanical bowel preparation is not recommended by ASCRS practice parameters. ¹⁶ However, adding oral antibiotics has been shown to decrease surgical site infection (SSI) rates. ²⁶ Also, there is data to support combined use of mechanical bowel preparation with oral antibiotics. In a nationwide analysis of outcomes of bowel preparation, combination of mechanical preparation with oral nonabsorbable antibiotics was associated with decreased postoperative complications of anastomosis leakage, superficial SSI, and intra-abdominal infections in left-side colon resections. ²⁷

Extent of Resection

Elective resection for recurrent sigmoid diverticulitis should include the entire sigmoid colon with margins of healthy colon and rectum. ¹⁶ Sigmoid colon should be resected and rectum should be used for anastomosis to prevent recurrences of diverticulitis after surgical treatment. ^{28 29} Rectum should be identified by splaying of tenia coli. Proximally the resection should be done to a normally appearing colon without abnormal thickness and inflammation. ^{16 29} In many cases, diverticulosis is present in descending or proximal colon as well. It is not necessary to remove all diverticula-bearing colon, if it is without inflammation and normal to palpation. Care should be taken to avoid incorporating diverticula in the anastomosis, as it might lead to leak. ¹⁶

Operative Approach

Operative principles should be the same, regardless of whether the sigmoid colectomy is performed laparoscopic, open, or robotically. Elective laparoscopic sigmoid resection for diverticulitis is a safe and feasible option. American Society of Colorectal Surgery recommends laparoscopic elective colectomy as long as the expertise is available. ¹⁶

In a meta-analysis, comparing laparoscopic versus open approach, laparoscopic approach is associated with a fewer postoperative complication rates. ^{30 31} Leak rates and anastomotic strictures are not increased in laparoscopic cases. Reduced rates of incisional hernias' wound infections, prolonged ileus, and need for blood transfusion are significant advantage of laparoscopic operations for diverticulitis. It also leads to a significant reduction in postoperative pain, ileus, and hospital stay. ^{31 32} There was a concern initially that specimen length is short in laparoscopic cases, and it can lead to a higher recurrence rate; however, this is not supported by literature. ²⁸

However, it should be noted that laparoscopic surgery in diverticulitis cases can be technically challenging and conversion to open surgery may become necessary. Hand-assisted laparoscopy (HALS) can also be utilized for difficult cases. The conversion rate for HALS is lower than that of straight laparoscopic cases and postoperative complications are less than in the open cases. ³³ The success of laparoscopic cases depend on surgeon expertise, appropriate patient selection, preoperative planning, and adequate use of laparoscopic instruments and adjuncts. ³⁴

Splenic Flexure Mobilization

With the advent of laparoscopy, there were concerns that lack of direct palpation and unwillingness to mobilize the splenic flexure would lead to inadequate colon resections in laparoscopic cases. ²⁹ However, studies have shown that laparoscopic colectomies without routine splenic flexure mobilization do not increase postoperative morbidity, especially anastomotic leak. ^{35 36} If the anastomosis can be done without undue tension, an additional step with increased time and potentially complications need not be undertaken. ³⁶ However, other surgeons feel that routine splenic flexure mobilization should be performed in all cases. ³⁷

Preservation of Inferior Mesenteric Artery

Ligation of the inferior mesenteric artery (IMA) at its origin is commonplace for oncological colon resections, as it may provide superior nodal clearance. In diverticulitis, the rationale for ligation of the IMA at its origin is that, it provides better length for a tension-free anastomosis. However, preserving the IMA is thought to preserve the natural blood supply to the rectum. ³⁸ Inadequate vascularity of the anastomosis is an important factor affecting leak rates. In a randomized trial, preserving the IMA lead to lower anastomotic leak rates in patients whose IMA was divided at its origin. ³⁸ According to study by Masoni et al, preservation of IMA also allows a reduction in rectosigmoid denervation. This leads to fewer defecatory disorders and better quality of life. ³⁹ The current practice is dependent on individual surgeon preference. ASCRS practice parameters recommend further randomized controlled studies to address this issue. ¹⁶

Ureteral Stents

Ureteric stents (conventional and lighted) can be used intraoperatively to aid in identification of the ureters. This may prevent injury of the ureters, especially in cases with dense retroperitoneal fibrosis or distorted tissue planes. ³⁴ There is controversy, whether the use of ureteral stents prevent ureteric injuries but there is a consensus that they aid in recognition if an injury occurs. ⁴⁰ Although colorectal operations are the second most common cause of ureteral injuries after gynecologic surgery, the complication rate is very low with the reported incidence being 0.24 to 1.95%. ⁴¹ Ureteral stent usage is associated with increased cost and longer operating time. In addition, there is a risk of ureteral injury and obstructive anuria from edema at the ureterovesical junction. ⁴⁰ Routine ureteral stents before sigmoid resection for diverticulitis is not recommended by the ASCRS. ¹⁶ and, The authors use patient characteristics and preoperative imaging as a guide to carefully select patients at high risk for ureteric injury who may benefit from the use of ureteric stents. Such patients include those with morbidly obesity, abnormal urinary anatomy, close association of ureter with diseased segment of colon, and retroperitoneal fibrosis.

Intraoperative Assessment of the Anastomosis

Anastomotic leak following left-sided colonic resections is not uncommon with incidence of approximately 6 to 11%. ⁴² Leaks cause significant morbidity and mortality. Various intraoperative techniques are used to assess anastomosis integrity. These include basic mechanical patency tests, endoscopic visualization techniques, and more recently, micro-perfusion assessment technology. ⁴³ ASCRS recommends routine leak test for colorectal anastomosis. ¹⁶ Intraoperative leak test by using intraoperative endoscopy allows to visualize the anastomosis and to assess its integrity. ^{42 43} Fluorescence perfusion angiography assessment can be done using indocyanine green dye and commercially available imaging systems with near-infrared light. ^{44 45 46} It has been shown to alter proximal transection site in left-sided colon operations, when it is used after traditional assessment of proximal colon vascularity by color, peristalsis, and pulsation of vessels. Authors have reported lower leak rates, but better quality randomized trials are needed to confirm if it reduces anastomotic leak rates. The technique is feasible and available with both laparoscopic and robotic platforms. ^{44 45 46}

If a leak test is positive, options range from simple suture repair to fecal diversion to reconstructing the anastomosis. No good quality evidence is available, but simple suture repair is discouraged. ⁴⁷ It is the practice of the authors of this article to reconstruct the anastomosis if the leak test is positive.

Role of Ileostomy

Diverting ileostomy can be used to protect a high-risk colorectal anastomosis. ⁴³ The need for fecal diversion should be seldom in elective operations for recurrent uncomplicated diverticulitis. Anastomosis is usually above the level of the peritoneal reflection and healthy colon is used for the anastomosis. The morbidity of an ileostomy is not insignificant, especially in elderly patients. Dehydration and readmission are a common complication of diverting ileostomy. Unsuspected abscess or significant inflammation of the colon can be sometimes encountered during elective colon resection. Clinical judgement should be used to decide at that time regarding primary anastomosis. Literature supports primary anastomosis even for carefully selected acute diverticulitis cases. ²⁴ In these patients, proximal diversion with an ileostomy may be considered, especially when the inflammation encroaches onto the proximal rectum.

Recurrence of Diverticulitis after Sigmoid Resection

Recurrence rates are approximately 3 to 13% after sigmoid colectomy for uncomplicated diverticulitis. ²⁸ Only factor predicting low recurrence was anastomosis to rectum rather than lower sigmoid. Retained distal sigmoid colon increases the odds of recurrent diverticulitis by four folds compared with creation of a colorectal anastomosis. ²⁸ Also, irritable bowel syndrome can be misdiagnosed to be diverticulitis in up to 9% of patients, even after imaging. ⁴⁸ These patients can continue to have symptoms even after sigmoid resection. ^{48 49}

Conclusion

Diverticulitis is very common in the western world. Better understanding of natural history of diverticulitis has led to significant change in management strategy for recurrent uncomplicated diverticulitis. Now, there is a consensus that decision for sigmoid resection for recurrent uncomplicated diverticulitis should be individualized and not based on number of episodes. Minimally invasive operations have better outcomes and newer techniques like fluorescence imaging are being studied to improve outcomes.