Surgical Management of Complicated Diverticulitis

Abstract

Diverticular disease is a prevalent condition that affects more people as they get older. Even though some patients have colonic diverticulosis with no symptoms and then require no treatment, some of the patients affected with this disease present repeated episodes of inflammation and end up requiring surgical treatment in an elective or urgent setting. When an acute episode of diverticulitis arises, it may require surgery, and these procedures are often challenging even for specialized colorectal surgeons. Furthermore, a lot has been written in the last years about what to do in an urgent scenario, ranging from just making a lavage of the abdominal cavity, to making a colonic resection with or without primary anastomosis (which brings more debate into the topic). Therefore, a chapter explaining the evidence-based management of acute colonic diverticulitis seems a relevant topic for this chapter.

1. Introduction

Diverticular disease arises from the formation of small bulges or pockets, (diverticula), more frequently affecting the left and sigmoid colon in the western countries. This is a prevalent disease that used to be associated with aging, but some studies have suggested a rising incidence in the younger population recently [1, 2, 3].

Diverticula can be found incidentally in colonoscopies performed for other reasons, but there is a risk that these become symptomatic in about 4% of these findings. Further, in the Netherlands, an estimation was made that about 22,000 patients will require medical attention for diverticular disease. Of those, 10% will present with complications such as abscesses or bowel perforation [4, 5].

When diverticulosis presents with symptoms (diverticular disease), the most common presentation is an uncomplicated scenario (abdominal pain without collections or other complications). In this case, the patient can be successfully managed with anti-inflammatory drugs with or without antibiotics [6].

On the other hand, a number of patients might suffer an acute presentation that requires an interventional approach, either percutaneous or surgical, because of complications like an associated abdominal abscess, bowel perforation, colonic fistulae to other organs, etc. This chapter will mainly focus on those situations and the best approach for each one of them. Even though, as we stated before, this is not the most frequent presentation of diverticular disease, the management of these patients is often challenging for the attending physician, which highlights the importance of the contents that will be developed here.

2. Management of complicated acute diverticulitis

2.1 Diagnosis and classifications of acute diverticulitis

Patients presenting with an acute diverticulitis episode can usually refer to several symptoms, including fever, vomiting, and abdominal pain mainly focused in the lower left quadrant.

When the suspicion of an episode of acute diverticulitis arises, the definitive diagnosis should be made by combining clinical findings, history of previous episodes and prior colonoscopies (which would also help to rule out other causes of colonic diseases, like malignancies), and serological markers to assess the inflammatory response (white blood count, C-Reactive protein, etc.).

As regards imaging methods, CT scan is the current gold standard, because not only it allows the physician to make a diagnosis but also to correctly stage the disease, looking for associated abscess, pneumoperitoneum, and free fluid in the abdominal cavity. In centers where CT scan is not available in the urgent setting, secondarily Ultrasonography can be used to look for inflammation related to the left colon and abdominal abscesses. However, this method is associated with significant limitations, starting with the fact that it is operator-dependent, in obese patients, it can be a challenging procedure, and it can miss essential findings like deep pelvic abscesses. Further, few or none of the classifications for acute diverticulitis are based on Ultrasonography, therefore it does not allow a proper stratification of the patient [7, 8, 9].

The most frequently used classification of acute diverticulitis based on imaging is the Hinchey classification [10], which stratifies the disease into four grades according to CT-scan information and operative findings:

1. Pericolic abscess

2. Abscess located in the abdominal cavity (not near the affected colon), in the pelvis, or in the retroperitoneum.

3. Purulent peritonitis.

4. Fecal Peritonitis.

More recently, Kaiser et al. [11] introduced a modification of this classification, including the size of abscesses (dividing grade I into A and B), and the severity of peritonitis.

Based on this classification, most guidelines propose different approaches for each stage, which will be further discussed.

Even though other classifications have been proposed for the stratification of acute diverticulitis based on CT-scan findings, these remain highly unadopted [12, 13].

2.2 Management of abdominal abscess associated with acute diverticulitis

About 15% of patients with an acute diverticulitis episode can present with an associated abdominal abscess, which can be pericolic (Hinchey I) or else pelvic (Hinchey II). The management of such abscesses should be guided by the size and clinical condition of the patient [14].

In stable, non-immunocompromised patients, with abscesses that are limited in size (less than 3–5 cm.), an initial antibiotic treatment can be started. Several publications have shown a high success rate without requiring interventional treatment (either percutaneous drainage or surgery). However, most data that support used to support this conduct come from observational studies with significant implicit bias, therefore it should be taken cautiously, and also, consider all patient’s clinical conditions while deciding the need for more invasive treatment [15, 16].

Larger abscesses require additional treatment (besides antibiotics), the percutaneous drainage being the preferred intervention when possible. Although ultrasonographic-guided drainage can be feasible, a CT scan has proven to be a more efficient method to guide this procedure. Further, obtaining a sample of the abdominal abscess will aid in identifying the specific causal agent and adequate antibiotics for it [17].

Lastly, surgery in the scenario of a patient with a diverticular abscess and no other complications should be the last choice, for those patients who do not respond to antibiotics, do not have an adequate window for percutaneous drainage, or in case of clinical instability.

In case a patient with a diverticular abscess has been successfully managed without surgery, the indication of colonic exploration (colonoscopy) afterwards (usually between 4 and 6 weeks after the episode) remains controversial, since most observational studies suggest that the risk of hidden malignancies in these patients is low. Nonetheless, the World Society of Emergency Surgery suggests that a colonoscopy would be advisable, in case the patient has not received one recently (weak recommendation based on low-quality evidence) (Figure 1) [18].

Figure 1.

Diverticular abscess treated with percutaneous drainage.

2.3 Management of patients with an abscess and pericolic gas

A relatively common finding in patients undergoing CT scan during the acute episode is pericolic gas (outside the bowel lumen), without free air or fluid elsewhere in the abdominal cavity. This finding (previously denominated acute diverticulitis with pericolic free gas) implies a blocked colonic perforation and its treatment may be challenging. Although these findings were associated with a more aggressive acute episode, requiring a longer length of stay, and keener to require emergent surgical treatment, initial conservative management with antibiotics has been successful in selected patients under strict clinical control [19, 20].

The most important study to date, regarding patients with pericolic-free gas, is the ADIFAS collaboration [21] published in 2023 by Tejedor et al. In this initiative, the authors recruited 810 patients from centers in Europe and South America who had diverticular pericolic free air with or without pericolic free fluid diagnosed by CT. Further, for patients who had distant free air or abscess, generalized peritonitis, or less than 1-year follow-up, focusing on the rate of failure of nonoperative management within the index admission as primary objective. In this cohort, 92% of patients were initially managed without surgery, of whom 94% were discharged after successful conservative treatment without surgery and complications. On the other hand, only 4.7% required an operation, and 1.6% percutaneous drainage. The factors associated with a higher risk of failure of non-operative management were free pericolic fluid on CT.

Based on the findings of the ADIFAS study, and on current recommendations of most guidelines, it seems reasonable that, in the event of patients presenting with pericolic free gas, those could be initially managed conservatively provided they are clinically stable. Particular care should be taken in those individuals who also present pericolic free fluid associated with gas (Figure 2).

Figure 2.

Patient with a localized collection and pericolic free gas.

2.4 Treatment of patients with diffuse peritonitis

Grades III and IV of the Hinchey classification include patients who present with diffuse peritonitis, which can be either purulent or fecaloid respectively. These groups of individuals can present with diffuse abdominal pain, fever, hemodynamic instability, and distant free gas and generalized free fluid on a CT scan. Sometimes, it can also be a consequence of the failure of conservative treatment (progression of the disease) of a patient who initially presented with pericolic-free gas. These patients represent a challenge for the surgeon since they are often clinically unstable and require an urgent procedure, without a colorectal specialist available.

An alternative to major surgery is the peritoneum lavage which consists of draining the free fluid and abdominal abscesses, afterwards performing a profuse peritoneal lavage of all four quadrants of the peritoneal cavity and finally putting drains and ending the procedure (provided a free perforation is not encountered during the surgical procedure, in which case this strategy would be contraindicated) [22, 23].

When it comes to the surgical approach of perforated diverticulitis with diffuse peritonitis, a minimally invasive or conventional exploration of the abdominal cavity, draining the free fluid, and performing a lavage of the abdominal cavity is mandatory. After these, the attending surgeon should make a decision:

1. In case the perforation is blocked (not uncommon in this scenario), put abdominal drainages and “bailout” (end the procedure).

2. Make a colonic resection involving the segment affected by the disease, and then either leave an end-stoma (Hartmann’s procedure) or perform a primary anastomosis with or without a proximal diversion.

Option one (formerly called peritoneal lavage and drainage) has been extensively evaluated in the literature, as, theoretically, it would be a very good option for an inexperienced surgeon to get the patient out of the problem with low morbidity.

To this extent, one of the first studies to report the results of this strategy was published by a Dutch group [22], reporting outcomes of this strategy in 38 patients. The morbidity of the procedure was high, with 17 patients developing complications after the procedure, 2 patients presenting with an overt perforation that was missed in the original procedure, and 2 patients dying after the intervention. Further, three patients had to be operated on after a successful lavage for recurrent diverticulitis. This group found some factors associated with unsuccessful treatment (more comorbidities, higher C-reactive protein, higher peritonitis index), proposing that the selection of patients to use this strategy should be of utmost importance.

After this initial report, three randomized controlled trials evaluated the potential use of this strategy in patients with diverticular peritonitis.

In 2016, the DILALA study [23] included 83 patients with Hinchey III diverticulitis randomized into laparoscopic lavage (39) and Hartmann procedure (36). This study found similar morbidity between both strategies, but shorter operating time and shorter hospital stay in the laparoscopic lavage group. After this initial report, the authors furtherly assessed the long-term (2-year follow-up) results of both strategies, finding that the laparoscopic lavage group had less risk of undergoing reoperations, with no difference in readmissions or mortality between both groups. Further, 3 patients in the lavage group vs. 9 patients in Hartmann’s group had a colostomy at 24 months, concluding that laparoscopic lavage seemed like a better option in these patients than doing a resection and stoma.

A second randomized controlled trial, the SCANDIV study [24, 25], involving 199 patients from Sweden and Norway, divided patients into two groups, those receiving a laparoscopic peritoneal lavage (101) and those who received a colonic resection (98). The primary outcome was severe postoperative complications. Even though the differences between groups were not significant in terms of morbidity mortality, length of postoperative stay, and quality of life after surgery, those patients in the laparoscopic lavage group had more reoperations. Operations, on the other hand, were shorter in this group. Interestingly, four sigmoid carcinomas were missed during the procedures that only involved lavage. For all the aforementioned findings, the conclusion of the study was not to support the use of laparoscopic lavage when compared to colonic resection.

The SCANDIV group also published the comparative analysis at a median follow-up to 59 months, showing that even though the stoma prevalence was higher in the resection group (33 vs. 8%, p: 0.002), recurrence of diverticulitis was higher following peritoneal lavage (21 vs. 4%, p: 0.004). In this group, 30% of patients required a sigmoid resection.

The LADIES collaborative study [26] was an RCT that involved patients operated at 34 centers from Belgium, Italy, and the Netherlands, which were randomized in either laparoscopic lavage or sigmoidectomy (LOLA group) or Hartmann’s procedure or sigmoidectomy with primary anastomosis. The primary endpoint was to assess the morbidity and mortality of the procedures during the first 12 months after surgery (using a composite score).

The LADIES trial was prematurely terminated after enrolling 90 patients for the LOLA group since the composite outcome to assess morbidity and mortality was much higher in the laparoscopic lavage group than in the sigmoidectomy group (39 vs. 19%, OR: 2.74, p: 0.004). Some other findings from this study are that control of sepsis (without the need for reoperations) was more successful in the sigmoidectomy group than in the laparoscopic lavage group (90 vs. 76%). Further, after being reoperated, one patient was found to have a missed diagnosis of colorectal carcinoma.

Lastly, an observational study published by Rossi et al. [27], assessed short-term results of laparoscopic lavage in 46 patients who had purulent peritonitis, reporting a 4% conversion to open surgery rate, with 24% of postoperative morbidity and no deaths after the procedure. Five patients in this group required reoperation because of uncontrolled sepsis after the original procedure.

This same group furtherly assessed the long-term results of 69 patients successfully treated with laparoscopic lavage for purulent peritonitis due to diverticular disease [28]. In this group, four patients had an elective sigmoid resection, whereas 42% of the cohort presented recurrent episodes of diverticulitis, with a cumulative global recurrence rate of about 50% at 5 years.

On the other hand, a number of observational studies have been published to date, highlighting that performing a primary anastomosis in patients operated in an urgent setting for diffuse purulent peritonitis (Hinchey III) could be an option in patients who are clinically stable during the procedure and immunocompetent [29]. For this strategy, the selection of patients is critical. The long-term results of the LADIES trial comparing Hartmann’s procedure versus resection and primary anastomosis showed that the latter was superior in terms of patients being without a stoma in the long term and overall hospitalization rates, without being associated with more morbidity or mortality after the procedure.

Furthermore, a recent meta-analysis [30] showed that, when a decision is made on performing a primary anastomosis on a patient being operated on for perforated diverticulitis, there seems to be no benefit associated with performing a proximal diversion to protect the colorectal anastomosis.

Lastly, for patients with fecal peritonitis (Hinchey IV), the treatment should involve resection of the affected bowel without a primary anastomosis (Hartmann’s procedure). Nevertheless, in carefully selected patients, a primary anastomosis could be performed.

Based on the aforementioned information, the recommendation for patients who present with diffuse peritonitis due to diverticular disease, in the event that a surgeon with sufficient expertise in colorectal surgery is available, would be to perform a laparoscopic sigmoid resection with primary anastomosis if the patient is fit and clinically stable. On the other hand, in the presence of a general surgeon without experience, laparoscopic lavage could represent a possible “bail-out” procedure in cases where a perforation is not detected during surgery. However, it must be noted that this strategy has been associated with questionable outcomes and a high risk of recurrent diverticular disease (Figure 3).

Figure 3.

Proposed algorithm for management of diverticulitis associated with an abscess or perforation.

2.5 Treatment of colovesical fistulas

Colovesical fistulas associated with diverticular disease are a significant clinical problem. They arise when the diverticula in the colon erodes through the bladder wall, leading to the formation of communication between the two organs. The presence of a colovesical fistula results in the passage of fecal material into the urinary tract, leading to a range of distressing symptoms.

The clinical presentation of colovesical fistulas associated with diverticular disease can vary widely, but common symptoms include:

• Pneumaturia (passing gas through the urine)

• Fecaluria (presence of feces in the urine)

• Recurrent urinary tract infections

• Dysuria (painful or difficult urination)

• Urgency and frequency of urination

• Abdominal pain, especially in the lower quadrants

• Flank pain

• Hematuria (blood in the urine)

• Bowel disturbances (constipation or diarrhea)

• Weight loss and fatigue in advanced cases

The prevalence of colovesical fistulas increases with age, as diverticular disease is more common in the elderly population. Moreover, men are affected more frequently than women, with a male-to-female ratio of approximately 2:1.

A thorough evaluation is essential for the accurate diagnosis of colovesical fistulas associated with diverticular disease. Imaging studies are important, including computed tomography (CT) scans, magnetic resonance imaging (MRI), and contrast studies such as a barium enema or cystography can help visualize the fistula and its extent. In CT scans, indirect signs such as the absence of a cleavage plane between the bladder and the sigmoid colon, or air inside the bladder, can lead to suspicion of a colovesical fistula.

The background of diverticular disease (multiple episodes of colonic inflammation) and repeated urinary infections can also lead to suspicion of a colovesical fistula. Lastly, a cystoscopy can give direct visualization of the bladder through a cystoscope, confirming the presence of the fistula and identifying its location and its relation to the ureters.

2.5.1 Treatment

The management of colovesical fistulas associated with diverticular disease requires a multidisciplinary approach involving gastroenterologists, urologists, and colorectal surgeons. The choice of treatment depends on the severity of the fistula, the patient’s overall health, and the presence of complicating factors. It is recommended that, before the patient is taken to the OR, stents are introduced in both ureters (right and left) which will serve as adequate markers to avoid undetected injuries during the procedure.

The operation usually consists of resecting the diseased bowel segment including the fistula tract and the affected portion of the bladder. This can be done either using a minimally invasive (in experienced centers) or a conventional approach.

After resecting the bladder, some surgeons feel it with water or methylene blue in order to diagnose defects that require suturing. However, often the defect is not detected, and most guidelines suggest that patients should use a urinary catheter for 7 days, after which it can be safely removed.

In patients with a colovesical fistula, after the bowel resection, a primary anastomosis without diversion can be safely performed without the requirements of a proximal diversion (Figure 4).

Figure 4.

CT-scan showing the sigmoid colon in close relation with the bladder (suspicion of colovesical fistula).

2.6 Management of diverticular bleeding

Diverticular bleeding is a significant cause of lower gastrointestinal hemorrhage, accounting for a substantial number of hospitalizations and medical interventions. The bleeding can range from mild to severe and may necessitate urgent medical attention.

Regarding clinical presentation, the most common symptom of diverticular bleeding is painless hematochezia (bright red or maroon blood in stools). Other symptoms may include abdominal discomfort, changes in bowel habits, and anemia due to chronic blood loss. It is essential to differentiate diverticular bleeding from other causes of gastrointestinal bleeding, such as angiodysplasia, inflammatory bowel disease, and colorectal cancer.

An accurate diagnosis of diverticular bleeding involves a combination of clinical evaluation, endoscopic examination, and radiological studies. Endoscopy, specifically colonoscopy, is the gold standard for diagnosing diverticular bleeding and locating the bleeding source. Colonoscopy allows for direct visualization of the diverticula and identification of active bleeding sites. Radiological techniques like computed tomography angiography (CTA) may be employed when endoscopy is inconclusive or contraindicated.

The management of diverticular bleeding aims to control hemorrhage, prevent recurrent bleeding, and manage complications. Treatment strategies may vary based on the severity of bleeding.

• Conservative Management: In cases of mild diverticular bleeding, where hemodynamic stability is maintained, conservative management may be appropriate. This includes supportive care, such as blood transfusions if anemia is severe, along with close monitoring for signs of clinical improvement or worsening.

• Endoscopic Management: For active diverticular bleeding observed during colonoscopy, endoscopic techniques can be employed to achieve hemostasis. These techniques include epinephrine injection, thermal coagulation (e.g., heater probe or argon plasma coagulation), and placement of hemostatic clips over the bleeding site.

• Surgical Intervention: If bleeding persists or recurs despite conservative and endoscopic measures, surgical intervention might be necessary, including the resection of the affected bowel with or without a primary anastomosis (depending on the patient’s general condition). Other less invasive procedures, like angioembolization, which targets the blood vessels supplying the diverticula, could be used in case the patient is too compromised to face surgery.

3. Conclusion

The surgical management of complicated diverticular disease plays a vital role in the treatment of patients who experience severe complications or fail to respond to conservative measures. This chapter has highlighted various scenarios related to complicated diverticulitis and has addressed complications such as perforation, abscess formation, fistula formation, and recurrent diverticulitis. Surgical intervention aims to control the disease, prevent life-threatening conditions, and improve the patient’s overall quality of life.

Management of complicated diverticular disease requires a personalized approach, considering the patient’s overall health, the extent of the disease, and the specific complication. Surgeons must carefully weigh the benefits and risks of each surgical option to optimize outcomes and ensure the best possible care for patients with complicated diverticular disease. Additionally, a multidisciplinary approach involving gastroenterologists, radiologists, and colorectal surgeons is crucial in the decision-making process and postoperative care to achieve optimal results and improve patient outcomes. Further research and advancements in surgical techniques will continue to enhance our understanding and treatment of complicated diverticular disease in the future.

Conflict of interest

The authors declare no conflict of interest.