Study of Etiology, Fatal Outcome and Different Surgical Techniques in the Management of Small Bowel Obstruction.

Prem Prakash, Nadeem Ahmad, Kanchan Sone Lal Baitha, Seema Rani Sinha, Anand Deoraj, Abhishek chaudhary Associate Professor, Department Of General Surgery, Indira Gandhi Institute Of Medical Sciences, Patna, India, Assistant Professor, Department of General Surgery, Indira Gandhi Institute of Medical Sciences, Patna, India, Junior Resident, Department of Biochemistry, Indira Gandhi Institute Of Medical Sciences, Patna, Senior Resident, Department of General Surgery, Indira Gandhi Institute Of Medical Sciences, Patna.


Introduction
Bowel obstruction occurs when normal propulsion and passage of intestinal contents cannot occur for whatever reason. [1] It represents a substantial burden on the national health care system of any country. In a study in United States it has been estimated that 1% of all hospitalisations, 3% of emergency surgical admissions to general hospitals and 4% of major celiotomies are done for bowel obstruction or procedures that require adhesiolysis. [2] Bowel obstruction can be dynamic (mechanical) where peristalsis is working against a mechanical obstruction or adynamic (functional) which results from atony of the intestine in absence of any mechanical cause. The obstruction can be simple where the blood supply is intact, strangulated where the blood supply is interrupted and closed loop where a segment of the bowel is obstructed at both proximal and distal ends. About 80% of bowel obstructions occur in small intestine; the other 10-20% occur in colon. [3] Acute mechanical obstruction is a surgical emergency. Emergency operation being defined as those types of surgeries that should be performed by necessity within 24 h of a patient's admission, or within 24 h of the development of a specific complication. [4] One of the key components in the management is early diagnosis as delay may result in bowel ischemia ,necrosis and perforation. Most of the common causes of small bowel obstruction are adhesions, intestinal tuberculosis, obstructed hernias etc.

Subjects and Methods
All consecutive patients admitted with a provisional diagnosis of small bowel obstruction from April 2016 to March 2018 were included in the study.
Exclusion criteria: Individuals <14years of age and terminally ill patients were excluded from the study. Conservatively treated patients were also excluded from the study.

Inclusion criteria:
All patients >14years and surgically treated were included in the study. Patients were followed up only up to their hospital stay which was 10 to 14 days.
All patients were subjected to thorough clinical examination, routine blood investigations (e.g. Complete blood count, random blood sugar) and radiological investigations (e.g. Plain x-ray abdomen supine and erect, ultrasound of whole abdomen and pelvis, computerised tomography scan of whole abdomen) wherever necessary. According to the etiology definitive surgical treatment was done.

Discussion
It was a retrospective study of the 95 patients admitted in a tertiary care hospital in eastern India. Analysis of different causes of obstruction showed that adhesion (31 out of 33 had a history of previous abdominal operation) was the commonest cause of small bowel obstruction (34.8%) followed by intestinal tuberculosis (26.31%) and obstructed/strangulated hernia (23.15%). A study conducted in Western Sudan, showed obstructed/strangulated hernia to be more prevalent than adhesion, while small bowel volvulus was found to be the least prevalent by far. [5] Intestinal tuberculosis with an incidence of 26.31% was found to be an important cause of intestinal obstruction in our present study correlating with the other studies done in a developing country like India e.g. Adhikari et al -14.17%. [6] Most common pathology was simple adhesion while stricture was found in 4 out of 16 patients. Terminal ileum and ileocecal region were predominantly involved. Hernias (obstructed/strangulated) as a cause of small bowel obstruction in the present series was about 23.15. In a different study done by other workers like Haridimos et al, and Ihedioha its incidence was 18.5% , and 18% respectively. [7,8] A study in Saudi Arabia, incidence was found to be 18.5%. [9] High incidence of strangulation in our study can be explained by the fact that most of the patients presents late for surgery when hernia becomes obstructed or strangulated. Incidence of small bowel volvulus was 4.2%. Gurleyik et al (1998) found the incidence to be 13%. [10] In miscellaneous group rare cases were included which comprised of 2 (2.1%) cases each of round worm impaction, meckel's diverticulum, intra-abdominal abscess and mesenteric cyst. One case (1.05%) was that of gall stone ileus. Incidence of malignancy was low 2.1% which was lower than studies done in western countries like Haridimos et al (13.4%) as they took large bowel tumors also into account and also incidence of malignancy here is lower than in western countries. [7] Resection and primary end to end anatomises was done in case of gangrenous segment of bowel due to any cause using 3.0 polyglactin suture. Where the rest of the gut was found unhealthy resection and ileostomy was done. In obstructed hernias with signs of healthy gut, simple reduction with open herniorrhaphy with 1 no. prolene suture was done. In some cases of intestinal tuberculosis where stricture was the culprit, stricturoplasty was done. In malignancy, resection and anastomosis was the operation of choice. In round worm impaction and gall stone ileus, simple enterotomy and removal of the causative agent was done. In mesenteric cyst (chylolymphatic cyst), enucleation was the operation of choice while in meckel's diverticulum, resection anastomosis was done. In intraabdominal abscess exploratory laparotomy and drainage of the abscess was done. Depending on the clinical settings and presence of related or unrelated comorbidities, mortality rates range from up to 3% for simple obstructions to as great as 30% when there is vascular compromise or perforation of the obstructed bowel. [11] The mortality rate in the present study was 10.52%. There was no intraoperative mortality. In a study in Tenwek hospital by Philip et al mortality was 4.5%. [12] It was important to note that in most of the patients there was more than one fatal complication like pulmonary complications (9.4%), anastomotic leak, shock, burst abdomen, fluid and electrolyte imbalance each being (5.2%). The high mortality rate could be explained by the fact that most of the patients were malnourished and had comorbidities, and they presented late leading to delay in the diagnosis ultimately presenting with strangulated bowel.

Conclusion
The surgical management of postoperative adhesions form a major share in the management of small bowel obstruction. Laparotomy as soon as possible should be done. Obstruction due to intestinal tuberculosis is common and often presents very late and most of the time requires ileostomy creation. It is better to create an ileostomy than to go for primary anastomosis whenever there is doubt of viability of rest of the gut or suspicion of any pathology e.g tuberculosis. In cases where rest of the bowel is found healthy primary anastomosis can be done. One of the keys to management of intestinal obstruction is early diagnosis. Particularly, accurate early recognition of strangulation is crucial because if ignored it leads to bowel ischemia, necrosis and perforation which increases morbidity and mortality significantly. Limitation of this study was lack of long term follow up and individuals < 14 years of age were not included.