There is still no international consensus among surgeons for treating uncomplicated and complicated diverticulitis11.
Analysing the American Society of Colon and Rectal Surgeons10 (ASCRS, 2020), the Association of Coloproctology of Great Britain and Ireland12 (ACPGBI, 2021), the European Association for Endoscopic Surgery13 (EAES 2020) and the World Society for Emergency Surgery4 (WSES, 2020) guidelines, it is noted that the choice of the most suitable surgical intervention is not defined by precise criteria.
Various trials and meta-analyses 6,14–18 have shown that PA is a safe operation; it can be performed in hemodynamically stable and immunocompetent patients.
Current guidelines indicate the possibility of choosing between HP and PA. However, they are less clear on the definition of the selection criteria.
WSES recommends primary anastomosis in patients who are hemodynamically stable and without comorbidities. Other guidelines are less clear on the parameters to consider to make a suitable choice.4
ASCRS entrusts the surgeon to evaluate the possible risk of anastomotic leakage before deciding on the type of surgery. Furthermore, ASCRS states that the choice should be weighed according to one's experience and ability.10
Instead, the companies EAES and ACPGBI indicate the possibility of choosing between the two different surgical procedures without defining a selection criterion.
Considering the retrospectively collected data, we first analyse the comparison between HP and PA.
Firstly, the sample analysed is different based on age. Patients undergoing PA are younger than patients undergoing HP. Also, C-reactive protein is higher in the HP, however, it remains above the threshold values in the PA group.
As expected from the literature data (DIVA arm of the LADIES Trial study6,16, WSES guidelines4, Uematsu et al.19 and some meta-analyses17,18,20,21), patients in the PA group had a Charlson Comorbidity Index and an ASA score lower than the HP group.
For this reason, it is correct to state that the choice of surgical procedure in our series was strongly linked to the comorbidity data.
It is therefore known that surgery should be related to the preoperative characteristics of the patient.
However, in our series, a statistically significant difference emerged in the two groups of the Hinchey and WSES classification.
Specifically, 13/15 (87%) of Hinchey 4 patients underwent HP versus 2/15 (13%) underwent PA.
The presence of stercoraceous peritonitis appears to be a discriminating parameter in the therapeutic choice. For years, the treatment of diverticulitis with stercoraceous peritonitis was HP. Over the past 20 years, there has been a gradual abandonment of this intervention in patients with good performance status.22–27
It is acceptable to think, analysing our data, that a high ASA score or a Hinchey 4 lead the surgeon to lean towards the most invasive operation; our study it emerges how surgeons take into account both conditions (comorbidity and presence of stercoraceous peritonitis) for the choice of the type of surgery.
Analysing Table 3 we can observe how the number of complications (Clavien Dindo > 2) is greater in the group of patients undergoing HP(p>0,05); this group is also characterised by a longer hospital stay. The interpretation of these data, we believe, is mainly linked to the worse preoperative conditions of the patients undergoing HP. This confirms what was previously stated.
As can be seen from Graph 1 the incidence of complications appears to be greater with the increase of the ASA score in the PA group compared to the HP group. The same attempt to evaluate the difference in the frequency of complications in the two groups based on the Hinchey and WSES score does not show such a dissimilar trend; the information obtained from the study show a higher incidence of complications with the increasing ASA score and the Charlson Comorbidity Index, compared to the Hinchey and WSES classification. As described above, many studies are confirming the importance of Physical Status.
In the LADIES Trial16 and the DIVERTI Trial3 , it can be seen that the incidence of complications in stercoraceous peritonitis does not depend on the randomization in the HP or PA group. Instead, it seems to depend on the preoperative comorbidities.
In light of the literature data and the still open discussions on the topic of diverticulitis treatment, we decided to focus on the analysis of the peritoneal lavage group.
Firstly, it was compared with the overall sigmoid resection group (considering HP and PA), then with the individual respective treatment groups.
Analysing the differences of patients undergoing sigmoidectomy vs LPL based on preoperative classifications, in absolute continuity with the WSES and ASCRS guidelines, LPL was not performed on Hinchey 4.
The most representative Hinchey class, which deserved the LPL, is Hinchey class 3. The same consideration, always statistically significant, can also be found by analysing the peritoneal lavage compared to the primary anastomosis group.
Analysing the complications of the sigmoidectomy vs LPL comparison, we can state that severe complications (Clavien-Dindo > 2) have a higher incidence in the LPL group; in 9 cases a second surgery was necessary (Clavien-Dindo > 3). This trend is confirmed by the single analyses between the LPL and HP groups and between the LPL and PA groups.
The most common complication associated with peritoneal lavage was an intra-abdominal abscess. 5 of 18 patients had another episode of diverticulitis with a mean and standard deviation of 8.4 ± 7.92 months requiring hospitalisation. What has been stated fully aligns with the literature data (DILALA7, LADIES15 and SCANDIV5). In particular, the LADIES Trial study (in the LOLA15 arm) was terminated early due to the onset of distant postoperative abscesses.
As in the LADIES study, also in our series, distant abscess collections occurred in about 11% of patients undergoing peritoneal lavage. After a 3-year follow-up of the LOLA study emerged that 21% of patients undergoing peritoneal lavage had distant postoperative abscesses and 27% had a recurrence of the pathology. On the other hand, 52% of the patients recruited benefited from the minimally invasive treatment of LPL, without requiring reoperation and without the reappearance of diverticular inflammatory symptoms years later.
Due to the results obtained from the LADIES15 study and other works (DILALA7 and SCANDIV5), the current guidelines, compared to previous years, are more reluctant to use laparoscopic lavage. The data collected from the previously mentioned trials show that laparoscopic lavage is associated with low mortality, fewer infectious complications at the level of the surgical wound and lower operating times and costs; however, there was a high risk of reoperation and postoperative morbidity.
Despite this, the heterogeneity between the different studies does not allow for a correct interpretation of the results. Outcomes may have been strongly influenced by: patient demographic differences (age, gender, comorbidities), anaesthesia, non-standardized surgery, and other intraoperative factors.10 In all the previously mentioned guidelines (WSES, ASCRS, EAES and ACPGBI) a cautious use of this surgical procedure is recommended in highly selected patients; however, inclusion criteria for LPL have not been identified.
To identify the category of patients that could benefit from the surgical treatment of LPL, we performed a case-control study with retrospectively collected data (Table 14). We divided the patients in the LPL group into two subgroups:
- Patients undergoing LPL uncomplicated (n = 9)
- Patients undergoing LPL complicated (n = 9)
We decided to use a Clavien-Dindo ≥ 3 as an inclusion criterion in the group of complicated patients, considering the need for a second surgery; while in the previous tables (Table 6, 9 and 12) a Clavien-Dindo ≥ 2 was considered (present in 11 cases), in this case, a Clavien-Dindo ≥ 3 was considered (detected in 9 patients). Two patients considered in the "uncomplicated" group experienced medical complications: the first had a postoperative course complicated by acute pulmonary embolism, while the second by symptomatic pulmonary atelectasis.
The comparison between the two groups shows that there is no statistically significant difference regarding the sex and age of the patients. There were no significant differences in surgical history, nor the number of previous episodes of acute diverticulitis. In fact, for most of the patients in the two groups, it was the first episode of inflammatory diverticular pathology. Another useful data is the absence of significant differences in the alteration of preoperative laboratory data.
As expected, there was no difference in Hinchey and WSES classification between the two groups.
In our series, there are no significant differences in the ASA or Charlson Comorbidity Index between complicated and uncomplicated subjects. It is therefore important to underline that the ASA classification is not sufficient in selecting patients.
From our analysis, it emerges that the BMI data alone is statistically significant in differentiating the two groups.
Evaluating the BMI data as a risk factor for complications, OR was calculated with a cut-off of BMI ≥ 25. OR was 1.6 with p-value = 1; setting the cut-off at a BMI ≥ 27, the OR was 16 with p-value = 0.049.
The data of BMI ≥ 27 as a risk factor for complications of laparoscopic peritoneal lavage, limited to the smallness of the sample we analysed, appears to be a new element not yet identified in the international literature (Table 15).
To exclude the possibility that overweight and obesity were risk factors for Clavien-Dindo ≥ 3 complications, we extended the case-control study to the remaining groups as well. We selected patients undergoing Hartmann's resection and sigmoidectomy with primary anastomosis. Both samples were divided into complicated and uncomplicated patients (Tables 16 and 18). No significant evaluations emerged in the two groups.
Many studies suggest that obesity and being overweight might be risk factors for short-term complications, depending on the surgical procedure. However, many reviews focused on the impact of high BMI on oncologic surgery28–33, but there aren't any important studies that evaluate the role of BMI on the risk of onset complication after surgical treatment of benign conditions like diverticulitis.
Obesity is thought to be a risk factor for infectious complications, in particular surgical wound infection34,35. However, more data are required to evaluate if BMI could be a predictive factor for the onset of complications in patients treated with laparoscopic peritoneal lavage.
Some studies, such as Greilsamer et al.36 and Radé et al.37, have identified other parameters to select patients for peritoneal lavage. Immunosuppression, ASA ≥ 3, and age are examples.
The limits of the study were its retrospective nature, small sample size, lack of previous
research studies on the topic of BMI related to surgical treatment of benign conditions.