1. Introduction

Diverticular disease (DD) is a common medical condition leading to hospital admissions and a significant cost to healthcare [1, 2]. The prevalence of DD is age dependent with 60% of the population developing diverticulosis by the age of 60 years [3]. Approximately 10-25% of these patients will develop diverticulitis and its associated complications [4]. Interval sigmoid resection has been suggested as means to prevent recurrent attacks of diverticulitis. Previous studies have suggested elective resection after two episodes of uncomplicated diverticulitis [5], however, this paradigm is being challenged by more recent studies [6]. Despite being a benign process, anterior resection for DD can be challenging. Complicated diverticular disease can be technically difficult thereby increasing morbidity in open or laparoscopic surgery. Anastomotic leak after anterior resection is one of the most detrimental complications causing significant morbidity and mortality for the patients [3]. It can lead to additional interventions, prolonged hospital stays, and can result in further operative intervention and death [7, 8]. Previous studies have quoted an anastomotic leak rate of 3-23% after anterior resection [9, 10]. There is a paucity of local data comparing the incidence of anastomotic leak between anterior resections for DD and neoplasia (NN) in the elective setting. In this study, we aim to compare the incidence of anastomotic leak in open or laparoscopic high anterior resections for diverticular disease and neoplasia.

2. Methods

A retrospective search was carried out on two prospectively maintained databases for patients presenting to Fremantle Hospital, Fiona Stanley Hospital and St John of God Hospital, Murdoch for an elective high anterior resection between the period of August 2007 and August 2016. High anterior resection was defined as a colorectal anastomosis above the peritoneal reflection. All patients who underwent elective high anterior resection for the indication of DD or NN were included in this study. The exclusion criteria for this study were-acute or subacute presentation, covering or previous stoma, multiple anastomoses, cystectomy and or liver resection. The diagnosis of anastomotic leak was established on radiology or the requirement of a therapeutic intervention within 30 days of the operation. Anastomotic leaks were graded according to the classification proposed by the International Study Group of Rectal Cancer [11]. Data was collected from electronic medical records which included age, sex, BMI, ASA, method of operation i.e laparoscopic or open and conversion rate. Post-operative data collected included mortality rate, morbidity, length of stay and anastomotic leak rate.

2.1 Statistical analysis

Data calculations were carried out using Microsoft Excel for Mac 2016 and GraphPad Software, Inc. (http://www.graphpad.com/quickcalc/). Data collected from medical records were classified as binomial, categorical or continuous. Chi-square and Student’s T-test were applied where appropriate. A p-value of <0.05 was considered statistically significant.

3. Results

Over the period of this study, 534 elective high anterior resections were identified. Out of 534 resections, 340 resections were performed for NN and 194 resections were performed for DD. The mean age of patients in NN cohort was 66 years and mean age of patients in DD cohort was 58 years. In the NN cohort, 41% of patients were female and 59% of patients were male and in the DD cohort, 50.5% of patients were female and 49.5% of patients were male. The mean ASA score was 2 in both groups (Table 1). The majority of operations were performed laparoscopically with 80% of the resections performed laparoscopically for NN compared to 84.5% of the resections performed for DD. The conversion to open surgery rate in was 2.9% in NN group and 2.4% in DD group. There was no statistically significant difference in conversion rate between two groups (p-value=1.0).

The incidence of anastomotic leak for the NN and DD groups was 4.7% (n=16) and 7.2% (n=14), respectively (p-value=0.244). Two patients in each group had a Grade B leak. They were treated with antibiotics only. The rest were classified as a Grade C leak and were managed operatively in theatre. Overall incidence of anastomotic leak was 5.6% (n=30). Median length of stay in hospital was 5 days in the NN group and 6 days in the DD group (p-value=0.304). In-hospital mortality was 0.03% (n=1) and 1.0% (n=2) in the NN and DD groups, respectively (p-value=0.300) (Table 2).

n=number

Table 1: Patient characteristics.

n=number

Table 2: Post-operative outcomes.

4. Discussion

The current guidelines for elective resection for diverticular disease are varied. The American Society of Colon and Rectal Surgeons (ASCRS) previously recommended elective sigmoid colectomy after one to two episodes of acute uncomplicated diverticulitis [12]. This recommendation has now changed to a more individualised approach. However, an RCT comparing surgery versus conservative management for recurrent and ongoing left sided diverticulitis showed that patients who had undergone elective sigmoidectomy had better quality of life scores than patients managed conservatively. The overall anastomotic leak rate for the study was 12% [13]. In juxtaposition, the various guidelines for resection of neoplasia show considerable equipoise [14, 15]. The comparison between NN and DD groups show that they were well matched in ASA score, laparoscopic approach and conversion rate. In our study, we found that patients undergoing anterior resection for DD were younger than patients in the NN group. This could either be related to the disease process or could be due to younger patients being offered and more agreeable to a resection for a benign condition.

Laparoscopic anterior resection for diverticular disease has previously been demonstrated to have acceptable morbidity and mortality [9, 16, 17]. Anastomotic leak post anterior resection is one of the most feared complications. The anastomotic leak rate in our study was acceptably low with 4.7% in the NN group and 7.2 % in the DD group. Comparison of the two groups did not reach statistical significance suggesting that anterior resection for DD is equally as safe as for NN within the limitations of this study. The laparoscopic conversion to open rate for NN and DD resections in our study was 2.9% and 2.4%, respectively. These rates are similar to those reported by previous studies [18, 19]. The major consequence of conversion is purported to be the increased morbidity and mortality rates as reported by some studies [20]. However, Shwandner et al. [21] illustrated that this was not the case in their series of 300 laparoscopic colorectal procedures. Other studies have also sub-analysed the conversion rates based on the complexity of diverticular disease to show that complicated diverticular disease had higher conversion rates than uncomplicated diverticular disease [22, 23].

The 30-day mortality rate in our series was 0.03% in the NN group and 1% in the DD group and (p-value=0.3). These rates are comparable to previous similar studies [18, 24]. The median length of stay was similar between the two groups, with 5 days in the NN group and 6 days in the DD group. A slightly higher length of stay in the DD group could be related to more technically difficult surgical dissection due to inflammation, fibrosis and adhesions from the disease process. These results were similar to those reported by Van Arendonk et al.[25] who looked at patients undergoing colectomy for diverticular disease, cancer or inflammatory bowel disease. A large study [26] using propensity score matching compared the post-operative outcomes following sigmoidectomy for DD and NN. This study concluded that elective sigmoidectomy for DD had a higher risk of infective complications whereas sigmoidectomy for NN had a higher risk for anastomotic leak. The weakness of this study lies in the variation of pre-operative work-up of patients and the operative techniques employed in performing sigmoidectomy. However, the strength of the study lies in the very large numbers analysed and therefore the conclusions of the study must be considered.

Our study had only moderate numbers over a 10-year period but the patients analysed were from a prospective database. Furthermore, all resections were performed by a single Colorectal unit thereby controlling for variation in techniques. All surgeons performed a high inferior mesenteric vessel ligation and splenic flexure was mobilised routinely with an end-end endo-luminal stapled anastomosis performed. The weaknesses of our study include the lack of secondary outcomes being recorded such as unplanned admission to intensive care unit, surgical site infections and deep vein thromboses. Additionally, moderate numbers may have prevented establishing a statistically significant difference in outcomes measured in our study.

5. Conclusion

Within the limitations of the retrospective review, we conclude that anterior resection for diverticular disease is safe and can be performed with acceptable morbidity and mortality.

Conflict of Interest

None.

References

1. Shaheen NJ, Hansen RA, Morgan DR, et al. The burden of gastrointestinal and liver diseases, 2006. Am J Gastroenterol 101 (2006): 2128-2138.
2. Everhart JE, Ruhl CE. Burden of digestive diseases in the United States part II: lower gastrointestinal diseases. Gastroenterology 136 (2009): 741-754.
3. Peery AF, Barrett PR, Park D, et al. A high-fiber diet does not protect against asymptomatic diverticulosis. Gastroenterology 142 (2012): 266-272.
4. Chapman J, Davies M, Wolff B, et al. Complicated diverticulitis: is it time to rethink the rules? Ann Surg 242 (2005): 576-583.
5. Stollman NH, Raskin JB. Diagnosis and management of diverticular disease of the colon in adults: Ad Hoc Practice Parameters Committee of the American College of Gastroenterology. Am J Gastroenterol 94 (1999): 3110-3121.
6. Janes S, Meagher A, Frizelle FA. Elective surgery after acute diverticulitis. Br J Surg 92 (2005): 133-142.
7. Eckmann C, Kujath P, Schiedeck TH, et al. Anastomotic leakage following low anterior resection: results of a standardized diagnostic and therapeutic approach. Int J Colorectal Dis 19 (2004): 128-133.
8. Khan AA, Wheeler JM, Cunningham C, et al. The management and outcome of anastomotic leaks in colorectal surgery. Colorectal Dis 10 (2008): 587-592.
9. Buchs NC, Gervaz P, Secic M, et al. Incidence, consequences, and risk factors for anastomotic dehiscence after colorectal surgery: a prospective monocentric study. Int J Colorectal Dis 23 (2008): 265-270.
10. Matthiessen P, Hallbook O, Andersson M, et al. Risk factors for anastomotic leakage after anterior resection of the rectum. Colorectal Dis 6 (2004): 462-469.
11. Rahbari NH, Weitz J, Hohenberger W, et al. Definition and grading of anastomotic leakage following anterior resection of the rectum: A proposal by the international study group of rectal cancer. Surgery 147 (2010): 339-351.
12. Wong WD, Wexner SD, Lowry A, et al. Practice parameters for the treatment of sigmoid diverticulitis-supporting documentation. The Standards Task Force. The American Society of Colon and Rectal Surgeons. Dis Colon Rectum 43 (2000): 290-297.
13. Van de Wall BJM, Stam MAW, Draaisma WA, et al. Surgery versus conservative management for recurrent and ongoing left-sided diverticulitis (DIRECT trial): an open-label, multicentre, randomised control trial. Lancet Gastroenterol Hepatol 2 (2017): 13-22.
14. Vogel JD, Eskicioglu C, Weiser MR, et al. The American Society of Colon and Rectal Surgeons clinical practice guidelines for the treatment of colon cancer. Dis Colon Rectum 60 (2017): 999-1017.
15. Costas-Chavarri A, Nandakumar G, Temin S, et al. Treatment of patients with early stage colorectal cancer: ASCO resource-stratified guideline. J Glob Oncol 5 (2019): 1-19.
16. Raue W, Paolucci V, Asperger W, et al. Laparoscopic sigmoid resection for diverticular disease has no advantages over open approach: midterm results of a randomized controlled trial. Langenbecks Arch Surg 396 (2011): 973-980.
17. Rossio F, Grillone G, Frattini P, et al. Effectiveness of elective treatment for colonic diverticulitis. J Soc Laparoendoscopic Surgeons 19 (2015): 2014.
18. Schwandner O, Farke S, Bruch H-P. Laparoscopic colectomy for diverticulitis is not associated with increased morbidity when compared with non-diverticular disease. Int J Colorectal Dis 20 (2005): 165-172.
19. Jones O, Stevenson ARL, Clark D, et al. Laparoscopic resection for diverticular disease. Follow-up of 500 consecutive patients. Ann of Surg 248 (2008): 1092-1097.
20. Marusch F, Gastinger I, Schneider C, et al. Importance of conversion for results obtained with laparoscopic colorectal surgery. Dis Colon Rectum 44 (2001): 207-214.
21. Schwandner O, Schiedeck THK, Bruch HP. The role of conversion in laparoscopic colorectal surgery: do predictive factors exist? Surg Endosc 13 (1999): 151-156.
22. Sher ME, Agachan F, Bortul M, et al. Laparoscopic surgery for diverticulitis. Surg Endosc 11 (1997): 264-267.
23. Vargas HD, Ramirez RT, Hoffman GC, et al. Defining the role of laparoscopic-assisted sigmoid colectomy for diverticulitis. Dis Colon Rectum 43 (2000): 1726-1731.
24. Elgazwi KEZ, Baca I, Grzybowski L, et al. Laparoscopic sigmoidectomy for diverticulitis : a prospective study. J Soc of Laparoendoscopic surgeons 14 (2010): 469-475.
25. Van Arendonk KJ, Tymitz KM, Gearhart SL, et al. Outcomes and costs of elective surgery for diverticular disease. A Comparison with other diseases requiring colectomy. JAMA 148 (2013): 316-321.
26. Ilyas MIM, Zangbar B, Nfonsam N, et al. Are there differences in outcome after elective sigmoidectomy for diverticular disease and for cancer? A nationwide inpatient study. Colorectal Dis 19 (2017): 260-265.