Keywords colon - diverticulitis - right colon diverticulitis - classification - treatment -
algorithm
Introduction
Diverticular disease of the colon is a common condition with increasing incidence
in the last decades, possibly related to changes in dietary and lifestyle patterns.[1 ] In Eastern populations, it is most commonly found in the right colon in up to 75%
of the patients, while in the West it accounts for less than 5% of the cases.[2 ]
[3 ]
[4 ]
[5 ]
[6 ]
The treatment of right colon diverticulitis (RCD) depends largely on the experience
of the surgeon, who is often much more familiarized with the management of left colon
diverticulitis (LCD). However, approaching RDC as LCD may not be the best practice,
since the clinical evolution of these two entities is distinct, and several articles
have shown that RCD occurs in younger patients, and has a milder clinical course and
a better response to conservative management, even in recurrent cases.[6 ] While there are several guidelines that provide evidence for the best management
of LCD, data regarding the treatment of RCD, especially in Western populations, is
scarce.[7 ]
[8 ]
[9 ]
[10 ]
In the present study, we report our experience with the management of RCD, including
diagnostic difficulties and treatment outcomes, and we propose a diagnostic and therapeutic
algorithm.
Methods
We retrospectively analyzed the medical records of patients diagnosed with RCD between
2008 and 2020 who were treated by a single experienced colorectal surgeon, the senior
author of the present manuscript. Data were collected regarding ethnicity, gender,
age, comorbidities, clinical symptoms, diagnostic exams, treatment outcomes, number
of relapses, and follow-up period. The study was approved by the Ethics Committee
at our hospital (CAAE number: 52763521.4.0000.0068).
Results
We included 12 patients with RCD with a mean age of 49.6 years. In total, 8 patients
were male, 9 were of Western origin, and 3 had clinical comorbidities, including obesity
and arterial hypertension. All patients referred abdominal pain in the right iliac
fossa, 8 (66%) had low-grade fever and 3 (25%) had nausea and vomiting. No patient
presented with intestinal bleeding. The demographic and clinical data are summarized
in [Table 1 ].
Table 1
Demographic and clinical data of patients treated for right colon diverticulitis
Variable
n (%)
Total number of patients
12 (100)
Male/Female
8 (66)/4 (33)
Age in years: mean (range)
49.6 (29–72)
Ethnicity: Western/Eastern
9 (75)/3 (25)
Symptoms
Abdominal pain
12 (100)
Fever
8 (66)
Nausea or vomiting
3 (25)
Diarrhea
2 (16)
Anorexia
2 (16)
Number of previous crises
1
9 (75)
2
1 (8.3)
3
1 (8.3)
4 or more
1 (8.3)
Mean follow-up in months (range)
49 (12–144)
Computed tomography (CT) of the abdomen was performed in 11 patients, and abdominal
ultrasound, in 1. The CT findings suggested acute RCD in 8 cases, acute appendicitis
in 2, and acute ileitis with a pericolic abscess suggesting Crohn's disease in 1 case.
Abdominal ultrasound suggested acute appendicitis in 1 patient. In 7 subjects, the
CT scan identified multiple diverticula throughout the right colon, and in 4, only
an isolated diverticulum in the cecum.
Surgical treatment was undertaken in 6 patients (50%), 4 through laparotomy and 2
by laparoscopy. The surgical indications were: suspected acute appendicitis (n = 3), acute ileitis with pericolic abscess (n = 1), RCD complicated by pelvic abscess not amenable to percutaneous drainage (n = 1), and RCD with multiple previous crises that impaired quality of life (n = 1). Of these cases, five patients underwent right colectomy and one underwent total
colectomy due to severe pandiverticulosis, all with primary anastomosis. One patient
developed anastomotic fistula and was reoperated with the performance of a double-barrel
ostomy. This patient underwent reconstruction of the intestinal transit after four
months, without any further complications. The anatomopathological examination of
all operated patients confirmed the diagnosis of acute RCD and none revealed malignancy.
The other 6 patients (50%) had uncomplicated RCD; they were treated with bowel rest
and antibiotic therapy (intravenous ceftriaxone or ciprofloxacin plus metronidazole)
and had good clinical response. Out of these six patients treated clinically, two
had recurrent episodes of pain and one required re-hospitalization for clinical treatment,
which was also successful. There were no deaths during follow-up.
Discussion
Relatively rare in the West, RCD accounts for 1% to 5% of patients with diverticular
disease, while in the East it is responsible for 75% of the cases.[2 ]
[3 ]
[4 ]
[5 ]
[6 ] Although RCD is still considered a rare disease in Western populations, its diagnosis
is being made more often, which may be related to the increase in incidence but also
to the improvement in accuracy of the imaging exams.[11 ]
[12 ]
Historically, diverticula of the right colon were considered “true” diverticula, since
all layers of the colonic wall were thought to be present in the diverticulum.[13 ] More recent studies with cadavers,[14 ]
[15 ] however, have shown that diverticula in this region can also be “false,” resembling
diverticulosis of the left colon, which has put into question the real pathophysiology
of this disease. Currently, the most accepted theory is that RCD results from a motility
disorder in the ascending colon and increased intraluminal pressure.[16 ]
From an epidemiological point of view, RCD affects younger patients in comparison
to LCD, usually around the fourth and fifth decades of life, and has a milder clinical
course.[17 ]
[18 ]
[19 ] The mean age of the RCD patients in our series was 49.6 years, which is similar
to other Western reports.[20 ] Most cases were uncomplicated, and only 2 patients had complicated disease with
pelvic abscess not amenable to percutaneous drainage and had to undergo surgical treatment.
The incidence of complicated RCD in the literature seems to be low, especially in
the first episode.[21 ]
The clinical diagnosis of RCD is complex. Most patients present with abdominal pain
in the right iliac fossa but without the classical migratory pattern associated with
acute appendicitis. Fever, anorexia and vomiting are also common symptoms.[22 ] In our series, the most common symptoms were abdominal pain and low-grade fever,
which is consistent with reports by other authors.[14 ]
[16 ]
[23 ]
Due to the clinical similarities to acute appendicitis and its similar incidence in
young adults, diagnostic errors are common. In our series, 1/3 (25%) of the patients
were misdiagnosed as having acute appendicitis or ileitis, which initially motivated
the indication for surgery. Although abdominal CT plays a fundamental role in the
initial investigation, the differentiation of RCD from appendicitis, right colon cancer
or ileitis in Crohn disease it not always straight-forward.[5 ]
[24 ]
[25 ]
[26 ] Monari et al.[20 ] reported a rate of 33% of diagnostic errors with imaging exams in this setting.
Even intraoperatively, there still may be diagnostic uncertainty, as shown in [Figure 1 ].
Fig. 1 Right colectomy specimen from a patient with pain in the right iliac fossa for 48 hours,
whose preoperative CT revealed an inflammatory mass (orange arrow) with involvement
of the cecal appendix (white arrow), and in whom complicated acute appendicitis could
not be ruled out. The diagnosis of acute cecal diverticulitis was only confirmed on
the anatomopathological examination.
As delaying the surgical treatment of acute appendicitis is associated with worse
outcomes, prompt surgery is often employed in cases of diagnostic difficulty, before
perforation and peritonitis occur.[19 ]
[27 ] Other less common differential diagnoses include epiploic appendagitis ([Fig. 2 ]) and omental infarction ([Fig. 3 ]). Epiploic appendagitis is an uncommon, benign, self-limiting clinical condition
that results from torsion or spontaneous venous thrombosis of the epiploic appendages.
The diagnosis is made by CT of the abdomen, and this condition should be treated clinically,
with analgesics and anti-inflammatory drugs.[28 ]
Fig. 2 Abdominal CT showing rounded densifications along the contramesenteric surface of
the right colon (arrow), measuring 2 cm, suggestive of epiploic appendagitis.
Fig. 3 Abdominal CT of a 51-year-old female patient with pain in the right hemiabdomen,
fever, and nausea, with a clinical suspicion of acute appendicitis. The CT scan revealed
the presence of a heterogeneous hyperdense fat mass with dense streaks in between,
suggestive of omental infarction (arrow).
Omental infarction is usually caused by torsion of the omentum or disturbances in
the vascular supply.[29 ] Its clinical presentation is similar to that of acute appendicitis, and the diagnosis
is made by abdominal CT or intraoperatively.
Colonoscopy has an important role in the investigation of patients with previous diverticulitis
episodes, although it should not be performed in the acute setting due to the risk
of perforation. The objective is to assess the extension of colonic diverticula and
to screen for adenomas and neoplasms.[22 ] Lee et al. evaluated 330 patients with uncomplicated RCD and revealed that 20.9%
had adenomas detected on follow-up colonoscopy, suggesting that routine colonoscopy
should be advised even for patients with an uncomplicated crisis.[30 ]
Regarding the classification of acute diverticulitis, in 1978, Hinchey et al.[31 ] proposed classifying perforated diverticulitis from stages I (pericolic abscess)
to IV (generalized fecal peritonitis) ([Table 2 ]). Since then, with the introduction of CT to daily clinical practice, Wasvary et
al.,[32 ] in 1999, modified the original classification by adding non-complicated diverticulitis
as stage 0, and subdivided stage I into two: stage Ia, with phlegmon or pericolic
inflammation, and stage Ib, with pericolic or mesocolic abscess ([Table 3 ]).
Table 2
Hinchey et al.[31 ] classification of acute diverticulitis (1978)
Stages
Hinchey et al.[31 ] classification
I
Pericolic or phlegmon abscess
II
Abdominal, pelvic, or retroperitoneal abscess
III
Generalized purulent peritonitis
IV
Generalized fecal peritonitis
Table 3
Hinchey et al.[31 ] classification modified by Wasvary et al.[32 ] (1999)
Stages
Modified Hinchey[31 ] classification
0
Colonic wall thickening
Ia
Phlegmon, inflammation confined to the colic wall
Ib
Pericolic or mesocolic abscess
II
Abdominal, pelvic, or retroperitoneal abscess
III
Generalized purulent peritonitis
IV
Generalized fecal peritonitis
The treatment of RCD depends on the severity of the episode, and it ranges from clinical
treatment with antibiotics to emergent Hartmann operation. For uncomplicated crises,
recent studies have shown high success rates with the clinical treatment, which includes
bowel rest with intravenous antibiotics, even for recurrent cases. Broad-spectrum
antibiotic therapy is usually administered intravenously during hospitalization for
two to four days and orally following hospital discharge.[6 ]
[26 ]
In our series, 50% (6) of the patients were treated clinically, and only 2 presented
recurrent episodes of pain, which were also treated conservatively. Other authors[17 ]
[21 ] have also reported similar findings, suggesting that RCD has a more favorable clinical
course than that of LCD. The two patients with recurrent chronic pain were treated
with mesalazine. Although the effectiveness of mesalazine for the prevention of diverticulitis
recurrence is uncertain, since there is no robust evidence, some authors[1 ]
[33 ] have shown symptomatic improvement when compared with placebo in patients with symptomatic
uncomplicated diverticular disease.
Half of our patients required surgical treatment, a high proportion compared with
those of other studies; this bias is due to our reference group in colorectal operations.
For more severe cases, classified as Wasvary II to IV, surgical treatment is recommended.
Regarding the type of surgical procedure, in our experience right colectomy is the
procedure of choice. Some Eastern authors[6 ]
[14 ]
[21 ] advocate diverticulectomy in cases of single diverticula and in immunocompetent
patients. The possible disadvantages of this approach are the difficulty in dissecting
the inflamed diverticulum and the risk of inadequate treatment, as there is a risk
of advanced adenomas and neoplasia.[22 ]
[30 ] Although none of our patients had incidental findings of cancer on the anatomopathological
examination, other authors[25 ]
[30 ] have reported them.
In view of the success of the non-operative treatment and the risk of surgical complications,
we consider that surgical treatment should be indicated only in cases with complications
such as fistulas, abscess, perforation with peritonitis, and in recurrent crises with
worsening quality of the life. Minimally-invasive surgery should be the method of
choice if expertise is available, except for patients with generalized fecal peritonitis,
in whom open surgery remains the standard approach.[34 ] Based on the experience observed in these patients and after reviewing the literature,
we propose a therapeutic algorithm to guide physicians in the diagnosis and treatment
of RCD when facing a patient with acute inflammatory abdomen and right iliac fossa
pain ([Fig. 4 ]).
Fig. 4 Diagnostic and therapeutic algorithm for the management of right colon diverticulitis.
Conclusion
Uncomplicated right colonic diverticulitis can be treated conservatively with a high
success rate. Recurrent cases that impact quality of life or complicated forms of
RCD should undergo surgical treatment, preferably a right laparoscopic colectomy.
The authors present a diagnostic and therapeutic algorithm to facilitate the diagnosis
and to guide the management of this disease.
