Surgical Management of Diverticular Disease in the Elective Setting

Abstract

Diverticulosis is a common condition that has increased in prevalence in industrialized countries over the past century. Estimates of developing diverticular disease in the United states range from 5% by 40 years of age up, to over 80% by age 80. It is estimated that approximately 20% of patients with diverticulosis develop diverticulitis over the course of their lifetime. Diverticular disease can be divided into simple and chronic diverticulitis with various sub categories. There are various instances and circumstances where elective resection is indicated for both complex and simple forms of this disease process. When planning surgery there are general preoperative considerations that are important to be reviewed prior to surgery. There are also more specific considerations depending on secondary problem attributed to diverticulitis, that is, fistula vs stricture. Today, treatment for elective resection includes open, laparoscopic and robotic surgery. Over the last several years we have moved away from open surgery to laparoscopic surgery for elective resection. With the advent of robotic surgery and introduction of 3D laparoscopic surgery the discussion of superiority, equivalence between these modalities, is and should remain an important discussion topic.

Diverticulosis is a common condition that has increased in prevalence in industrialized countries over the last century. Estimates of developing diverticular disease in the United States range from 5% by 40 years of age up, to over 80% by age 80. ^{1 2 3} It is estimated that approximately 20% of patients with diverticulosis develop diverticulitis over the course of their lifetime. This disease process accounts for about 300,000 hospitalizations yearly in the United States. This has resulted in over 1.5 million days of inpatient care and roughly 1.5 million outpatient visits each year are secondary to diverticular disease. ^{4 5 6}

Diverticular disease can be defined as having diverticula, and for 80 to 90% of patients, this is synonymous with asymptomatic disease. Diverticulitis is the symptomatic form of diverticulosis and is categorized into (1) acute, (2) chronic, and (3) complex. Each of these categories has subclassification. Please refer to Table 1 . ^{5 6 7}

Table 1. Classification of diverticulitis.

Diverticulitis
1. Acute: Symptoms with inflammation
a. Uncomplicated: Localized disease
b. Complicated: Perforation
2. Chronic: Persistent disease
a. Atypical: Symptoms without systemic signs
b. Recurring or persistent: Symptoms with systemic signs
3. Complex: Fistula, stricture, or obstruction

Acute Diverticulitis (Uncomplicated and Complicated)

It is well documented in the literature that the vast majority of patients admitted with acute uncomplicated diverticulitis are managed medically with antibiotics. Etzioni et al demonstrated from 1998 to 2005 a fall in the proportion of individuals who underwent surgery following admission for diverticulitis from 17.4 to 14.4%, which correlated with a rise in percutaneous drainage from 1.4 to 1.6%. ^{8 9 10 11 12} Individuals who present with complicated disease with local abscess less than 4 cm can also be treated with antibiotics. ¹³ If local perforation is present (Hinchey stage 1 and 2), it can be treated with antibiotics and percutaneous drainage. ⁷ Surgery in the acute setting is indicated for those patients (1) who fail to improve with antibiotic therapy, (2) patients who do not improve with percutaneous drainage, (3) if there is a larger abscess and it is inaccessible to drainage, and (4) if the patient has purulent peritonitis or fecal peritonitis (Hinchey stage 3 and 4). For Hinchey classification, please refer to Table 2 .

Table 2. Hinchey's classification of complicated acute diverticulitis.

Stage 1: Small or confined pericolic or mesenteric abscess

Stage 2: Larger abscess extending into the pelvis

Stage 3: Purulent peritonitis

Stage 4: Fecal peritonitis

Indications for Surgical Management of Diverticular Disease in the Elective Setting

Elective Resection after an Episode of Acute Noncomplicated Diverticulitis

The decision to recommend elective sigmoid colectomy after recovery from uncomplicated acute diverticulitis should be individualized. Based on practice parameters for the treatment of sigmoid diverticulitis put forth by the Clinical Practice Guideline Task Force of the American Society of Colon and Rectal Surgeons in 2014.

Those patients who presented with uncomplicated diverticulitis and were treated nonoperatively demonstrate recurrent rates ranging from 13 to 23%. They also have low rates of subsequent complicated disease or need for emergency surgery (< 6%). ^{14 15 16 17 18 19} In addition to this, the estimated risk of needing emergency surgery with stoma formation is 1 in 2,000 patient-years of follow-up. ¹⁰ Therefore, elective surgery after the initial attack of simple acute diverticulitis is not recommended nor indicated. After resolution of an episode of acute diverticulitis, the colon should typically be evaluated with colonoscopy to confirm the diagnosis, if this is the first episode or recent colonoscopy has not been performed to rule out other pathology, including malignancy and inflammatory bowel disease.

Elective Resection after Multiple Episodes of Diverticulitis

The literature demonstrates that patients with more than two episodes are not at an increased risk for morbidity and mortality when compared with patients who have had fewer episodes. This shows that this disease process is not progressive in nature and that those individuals who present with complex disease will do so on their initial presentation. ^{14 17 20 21} It has also been demonstrated that elective resection following the fourth episode of acute simple diverticulitis is not associated with an increased colostomy or mortality rate when compared with the first episode and the elective colectomy was the most cost effective after three to four episodes. ^{22 23} When discussing surgery with the patient, treatment should be individualized, and the surgeon should take into consideration medical condition of the patient, risks of surgery versus effects on patient lifestyle (professional and personal) imposed by recurrent attacks, inability to exclude carcinoma, severity of the attacks as well as chronic or lingering symptoms that may constitute “smoldering” disease. ^{14 24} In addition to the above, the patient should be aware of potential poor functional outcomes and persistent abdominal symptoms after elective sigmoid colectomy for diverticulitis. ^{25 26}

Elective Resection in Transplant Patients and Immunosuppressed Patient Population

Transplant patients and patients who require chronic corticosteroid therapy are more likely to fail medical management as well as have a high mortality rate when treated with medical therapy alone for acute diverticulitis. In addition to this patient population, patients with chronic renal failure or collagen-vascular disease have a greater risk of recurrent and complicated diverticulitis. They also have a higher risk of requiring emergency surgery. ^{27 28} In these patients, one should have a lower threshold to discuss and recommend definitive surgical treatment after the patient's initial hospitalization. Surgery for those individuals with a history of acute uncomplicated diverticulitis who are preparing for a solid organ transplant is still controversial.

Elective Resection Based on Young Age (< 50 Years)

Diverticulitis among young patients has historically been associated with worse clinical outcomes, and young age has therefore been used as an indication for elective surgery following recovery after an acute episode of even uncomplicated diverticulitis. To support this, data from previous studies were small and lacked definition characterizing the difference between severe versus nonsevere disease. In some cases, there was also a concern of possible misdiagnosis. Previous recommendations were based on data that gave little evidence to support a different management strategy in those individuals younger than 50 years. ^{7 14} More recent data suggest that age < 50 years does not increase the risk for worse clinical outcomes. ^{10 29 30} These data have also demonstrated similar biological nature of the disease in young patients and older patients, comparable rates for resection at the initial hospitalization, and rate of stoma formation during subsequent attacks. ^{31 32} Young patients do have a higher risk of recurrence of diverticulitis when compared with their older counterparts. The rate of recurrence is relatively low with 27% of young patients developing a recurrence. Eglinton et al also demonstrated that only 7.5% of young patients required subsequent emergency surgery, and it has been shown that there is only a 2.1% rate of emergency surgery at subsequent attacks. ^{14 16}

Elective Resection after Episode of Complex Diverticulitis

Complex diverticulitis includes those episodes associated with fistula of any form (colovesical, colovaginal, colocutaneous, coloenteric, etc.), obstruction, or stricture. Elective or semielective resection is indicated. ¹⁴

Surgical Considerations for Colovaginal, Colovesical, and Colocutaneous Fistula

Fistula formation is a well-known complication of diverticular disease. It is estimated to occur at a rate of 2%. ³³ The condition arises from the formation of adhesions through phlegmonous disease or a locally walled off perforation between the portion of the affected colon and viscus in question. A fistula is formed secondary to this penetrating process. ⁷ Colovesical fistula is the most common form of colonic fistula. It accounts for approximately 50% of all fistulas secondary to this disease. The second most common cause of fistula was colocutaneous followed by colovaginal, coloenteric, and then other unusual manifestations including (coloreteric, colouterine, and even fallopian tube). ^{7 34}

Colovesical fistula presents most commonly with urinary tract symptoms. Pneumaturia is the most frequent urinary frequency, dysuria, fecaluria, and hematuria. Other symptoms include abdominal pain and fever, but less than 25% of patients have these symptoms. The various studies that can be used to diagnose those patients whom one suspects of having a colovesical fistula include urinalysis, urine culture, barium enema, cystoscopy, cystography, colonoscopy, and computed tomography (CT) imaging. ³⁵ Plain X-ray and CT imaging will often show intravesical gas. It is important to ensure no recent instrumentation of the urinary tract occurred before obtaining CT imaging of the abdomen and pelvis. CT scan is the most accurate diagnostic tool to confirm there is a communication between the urinary and gastrointestinal tracts; cystoscopy usually will demonstrate an inflammatory reaction rather than the fistula itself. Colonoscopy will unlikely show fistula but will assist in evaluating the presence of diverticulosis, inflammatory bowel disease as well as malignancy. Overall all it does have a low sensitivity and specificity in detecting the fistula itself. ³⁶ A one-stage surgery is a preferred approach.

A colovaginal fistula may present as late sequelae of diverticulitis, but it is rare. ³⁷ It almost never occurs without previous hysterectomy. Symptoms include discharge feces, pus, mucus, or gas through the vagina. The examination will reveal an opening or a granular area at the apex of the vagina. Imaging may assist in confirming a diagnosis. As with colovesical fistulas, colonoscopy is important to rule out any other etiologies, and it is preferable to undertake a one-staged surgery. ³⁸

Colocutaneous fistula occurs most likely secondary to retroperitoneal perforation by diverticulitis or tumor. External opening is most commonly seen on the abdominal wall. However, tracts may extend to the thigh or perineum where it can be mistaken for the external opening of fistula-in-ano. When patients present with thigh abscess with cultured enteric flora, one must be concerned that there is a colocutaneous fistula present. ⁷ Finally, when patients present with this clinical picture a differential diagnosis of Crohn's disease and possible malignancy must be considered. ³⁹

Operative Considerations Specifically for Fistula

1. Intraoperatively the sigmoid colon is usually tethered to the pelvis, fixed to bladder wall or vagina or uterus in females.

2. Fistula can be divided using sharp or blunt dissection.

3. Not necessary to close a vaginal or bladder defect, it will heal once the portion of the colon has been removed. No need to excise the fibrotic area in the area of the bladder or vagina to healthy tissue unless there is a concern for malignancy.

4. Consider omental flap.

Surgical Considerations for Stricture

A stricture can result from the chronic inflammatory process secondary to thickening and contraction of the bowel wall. This can ultimately lead to bowel obstruction. Symptoms can be secondary to large bowel obstruction and small bowel obstruction secondary to adhesions from inflammation. Symptoms including nausea, vomiting, and constipation in the acute settings improve with effective medical treatment. If they do not subside consideration for surgery is indicated. Stricture formation may also result from recurrent episodes of diverticulitis via progressive fibrosis of the colonic wall, without evidence of persistent inflammation on CT imaging. Attributing symptoms may include, change in bowel habits, bloating, constipation. Obstruction from diverticular disease accounts for approximately 10% of patients who present with large bowel obstruction. ⁴⁰

Colonoscopy, CT scan, or gastrograffin enema should be used for further evaluation of colonic stricture. They are used to distinguish between a diverticular and a neoplastic stricture. If one is unable to characterize the stricture before surgery and diagnosis remains uncertain, one must adopt principles of oncologic surgery, including en bloc resection. Balloon dilation has been attempted if malignancy has been excluded with the potential goal of colonic decompression to allow a one-stage procedure. ¹⁴ Colonic stenting has also been performed for large bowel obstruction. Both procedures include a risk of colonic perforation. Meisner et al demonstrated 96 patients who underwent stenting, with 8 being for benign disease. Only three of the eight patients had benefit with associated morbidity. They could not recommend the procedure for diverticular disease. ⁴¹

Patients with stricture causing large bowel obstruction require surgical resection. A primary anastomosis can be performed unless the quality of proximal colon is significantly dilated or of poor quality. One can consider on table lavage. If patient is not deemed a candidate for primary anastomosis or is a poor surgical risk, then a Hartmann's procedure should be considered. ⁷

Preoperative Considerations for Diverticular Surgery

Ureteral Catheters

Routine use of ureteral catheters is not indicated, based on literature, as ureteral injury during elective colectomy for diverticulitis occurs in less than 1% of cases. ^{14 42 43} The routine use of stents can result in longer operative times, added costs, and risks of stent-related complications. Insertion of ureteral catheters should be considered in those cases in which the patient is morbidly obese, have undergone radiation, resurgery, or preoperative imaging demonstrating abnormal anatomy. ^{6 44}

Bowel Preparation

The literature has demonstrated that routine use of oral mechanical bowel preparation is not required. Both randomized trials and by meta-analysis, have shown that the lack of bowel preparation does not influence the rates of wound infection or anastomotic failure. ^{14 45 46} To implement a bowel preparation or not is per surgeon preference. Unlike the oral mechanical bowel preparation, research has demonstrated that the use of oral antibiotics can decrease surgical site infections after elective colon resection.

The use of nonabsorbable oral antibiotics, such as erythromycin, neomycin, and metronidazole, decrease overall surgical site infections, when administered preoperatively (4.5 vs. 11.8%; p  = 0.0001), organ space infections (1.8 vs. 4.2%, p  = 0.044), superficial surgical site infections (2.6 vs. 7.6%; p  = 0.001), and ileus (3.9 vs. 8.6%, p  = 0.011), in comparison with mechanical preparation alone. ^{47 48 49} A large study put forth by Veterans Affairs with a cohort of almost 10,000 patients compared the rates of surgical site infection with no bowel preparation (18.1%), mechanical bowel preparation only (20%) to those who received oral antibiotics alone (8.3%), or in addition to a mechanical bowel preparation (9.2%). ⁵⁰ Toneva et al, demonstrated that oral antibiotic use with or without mechanical bowel preparation was associated with decreased surgical site infections, shorter length of stay, and lower rates of readmission (no preparation, 6.1%; mechanical bowel preparation, 5.4%; antibiotic bowel preparation, 3.9%; p  = 0.001). ⁵¹ Krapohl et al and Englesbe et al have demonstrated that the routine use of oral antibiotics preoperatively does not increase rate of Clostridium difficile colitis postoperatively, 1.3 vs. 1.8%, p  = 0.58). ^{49 52}

Intraoperative Considerations for Diverticular Surgery

Technical Considerations

The extent of colon resected is determined intraoperatively based on the anatomy and the quality of the tissues. The extent of elective resection should include the entire sigmoid colon with margins of healthy colon proximally and rectum distally. Resection of the colon should not be performed above the splaying of the tenia of the proximal rectum. This is important in minimizing the recurrence of diverticulitis as a colo-colonic anastomosis significantly increases the risk of recurrence. ^{53 54} When the proximal rectum is inflamed, one may have to perform a more extensive rectal resection with a lower rectal anastomosis. The proximal extent of resection in the descending colon is chosen by the absence of thickened, hypertrophic tissue and inflammation. Although one does not have to remove all diverticula-bearing colon, one should be aware not to incorporate false diverticula on the proximal side of the staple line when performing the anastomosis. This will increase the risk of anastomotic leak. Before completing the anastomosis, one must be cognizant that the blood supply for the anastomosis is appropriate, there are no twists in the mesentery, and no tension will be placed on the anastomosis. At times the splenic flexure will require mobilization to allow a tension free anastomosis. A leak test of the colorectal anastomosis should be performed during surgery for sigmoid diverticulitis as intraoperative leak testing identifies suboptimal anastomoses that should be repaired, revised, or redone, before completing the surgery or creation of proximal diversion if indicated. Ricciardi et al and Beard et al have both demonstrated that routine leak testing after colorectal anastomoses reduces postoperative leak rate. ^{55 56} Regarding transection of the inferior mesenteric artery and vein, an attempt should be made to maintain the inferior mesenteric vessels to decrease the risk of an anastomotic leak, optimize functional results, and decrease sexual dysfunction from intraoperative nerve injury.

Laparoscopic Surgery and Robotic Surgery

In the elective setting, approach for diverticular surgery with a minimally invasive approach with laparoscopic or robotic surgery or with an open approach can be considered. The practice parameters of sigmoid diverticulitis put forth by the task force for the American Society of Colon and Rectal Surgeons have recommended a laparoscopic approach for elective colectomy. This is based on high-quality evidence from multiple randomized control trials. ¹⁴ These trials have demonstrated that there is a short-term benefit with laparoscopic surgery when performed by an experienced surgeon trained in laparoscopic surgery. These short-term benefits include, the decreased length of stay, decreased ileus, decreased intraoperative blood loss, and decreased pain. Purkayastha et al demonstrated through meta-analysis of 19,608 patients confirmed the short-term benefits listed above in addition to the demonstration of a decrease in pulmonary, cardiovascular complications, and infection rates. The meta-analysis did demonstrate longer operating times for the laparoscopic group. ⁵⁷ Long-term benefits include up to a 66% decrease in incisional hernias when compared with open surgery or in those cases where the surgeon had to convert to an open surgery and improved quality of life. ^{14 42 58 59 60} A large series of 500 patients published by Jones et al demonstrated that laparoscopic surgery was safe for resection of diverticulitis of any type. Indications for surgery included recurrent diverticulitis in 77% of the population with fistulalization and perforation representing 9 and 10% of the patient population. ⁶¹ Conversion from laparoscopic to open surgery is higher in diverticulitis has been demonstrated to be higher when other pathologies. ^{7 62} Conversion to open surgery has been attributed to elevated body mass index (BMI), adhesions, older age, surgeon inexperience, and complicated disease. Conversion rates have been demonstrated to range anywhere between 10 and 69%. ^{63 64 65 66 67 68} Conversion from a minimally invasive technique to an open procedure should not constitute a surgical complication; however, the clinical consequences of converting are not being ignored. On conversion, length of stay (LOS), higher complication rates, slower return to bowel function, and increased need for opioid analgesics. ^{66 67}

Chang et al have demonstrated the benefit of hand-assist approach in decreasing conversion rates when comparing both techniques. The purely laparoscopic group demonstrated a 13% conversion and 0% conversion when utilizing or switching to a hand-assist approach. The efficacy of a laparoscopic hand-assist approach has also been demonstrated by Lee et al, as an adjunct to laparoscopic surgery for complex diverticular disease. ⁶⁹

Minimally invasive surgery for colon and rectal surgery has continued to expand over the last decade beyond laparoscopic and hand-assist surgery and now includes robotic surgery. Although the debates will continue between these modalities, robotic colectomy has been shown in the literature to be a safe and comparable alternative to laparoscopic surgery. ^{70 71 72 73} Advantages attributed to da Vinci robotics (Intuitive Surgical, Inc.) include (1) surgeon-controlled, three-dimensional (3D), high-definition optics, (2) stable platform, (3) improved strength, and (4) articulating instruments. It was our subjective experience that the superior 3D high definition, and (5) decreased rate of conversion to an open procedure. Maciel et al compared laparoscopic surgery for the colovesical fistula to the robotic approach. The groups were similar in demographics (sex, BMI, age). The cases were consecutive and not selected. Eight cases (14.55%) were converted in the laparoscopic (LAP) group ( n  = 55), and no cases (0%) were converted in the robotic group ( n  = 20). The authors felt that advantages attributed to robotic surgery may be responsible for the lower conversion rate in the robotic group. ⁷⁴ These findings have also been supported by a systematic review and meta-analysis, by Maeso et al who reported a 2% robotic to open conversion rate and a 6% conversion to another form of surgery. ⁷⁵ Antoniou et al demonstrated a 0.4% conversion rate ( n  = 440) for robotic rectal resection in the published literature. ⁷¹ MRC CLASICC trial data have also demonstrated higher morbidity and mortality associated with converted laparoscopic cases, which suggested a benefit to avoiding conversion if possible. ⁷⁶

Maciel et al also showed in their series that conversion from robotic surgery to open demonstrated a shorter length of stay and fewer complications. It is important to note that the decrease in complication rates did not reach statistical significance and further study is required to evaluate the role robotic technology in the reduction of complication rates in diverticular surgery. ⁷⁵ When discussing robotic surgery one must be aware of the longer operating times when compared with laparoscopic surgery as well as cost. Laurent et al have reported a mean operating time of 172 minutes (range, 100–280 minutes) for left colectomies for diverticulitis, and a mean hospital stay of 5.7 days (range, 3–12 days). In order to justify the use of robotic technology, with its increased cost and longer operative times, future studies will have to demonstrate advantage over laparoscopy. ⁷⁷ Arguments have been made that better visualization with 3D technology and articulating instruments may offer an advantage to robotic surgery over laparoscopy when dissecting hard and inflamed tissues resulting in a potential decrease in conversion rates. With the advent of 3D laparoscopic cameras and evolving laparoscopic instruments, it will be interesting to see the results of future studies and outcomes comparing the two modalities.

Conclusion

The spectrum of disease that is managed with elective surgery ranges from simple to complex disease. Multiple considerations must be undertaken in the preoperative evaluation of the patient who presents with diverticular disease, especially in those cases where complications have occurred secondary to diverticular diseases, such as fistula and strictures. Thoughtful preoperative planning, intraoperative decisions, and technical considerations are extremely important for a successful postoperative result in this patient population. With the advent and introduction of the 3D laparoscopic camera, the debate regarding robotic surgery, laparoscopic surgery, and superiority of each will continue, with each publication comparing these technologies. Regardless, both of these technologies for sigmoid resection for diverticulitis are technically challenging surgeries. To have successful outcomes with either of these techniques, one requires specific training and adequate experience. As a result of advancement in surgical technology over the last 25 to 30 years, an open surgical approach for diverticular disease is no longer the primary surgery of choice. However, this is an option that can and should be used when indicated based on surgeon's judgment and experience.