Medical Imaging/Radiology: Small Bowel Obstructions Assessment Answer

Discuss about the Medical Imaging/Radiology for Small Bowel Obstructions.

Condition/Pathological Process/Medical Significance

The small bowel obstructions (SBO) are the category of intestinal or bowel obstruction that is functional or mechanical blocks in the intestine that leads to hindrance in normal intestinal. These SBOs can lead to hindrance in normal transmission or excretion of digestion products from intestine. The major causes of SBO are barbed sutures, volvulus, ischemic strictures, pseudo-obstruction, intestinal atresia, and artery syndrome. Further, occurring of adhesions due to surgeries (abdominal), Crohn’s disease also causes small bowel obstruction. The typical clinical indications of SBO formation are the crimpy abdominal pain, constipation, vomiting & nausea, abdominal distension (1, 4).

Path

ological Process and Medical Significance

The occurrence of SBO in the intestine leads to accumulation of GI secretions and gas in bowel proximal of the intestine that is basically the site of Small bowel obstructions. This action further enhances the cell secretory function leading to increasing in more bowel proximal accumulation. Hence, active peristalsis gets initiated above and below the obstruction (2).

At peak level of obstruction, there is the occurrence of vomiting that leads to enhancement of intraluminal pressures which in turn causes bowel wall lymphedema. The increased intraluminal pressure in capillary beds leads to accumulation of fluids and other materials in intestinal lumen enhancing increased mortality and morbidity.

The formation of adhesions occurs when the bowel twist on its mesenteric pedicle which if left untreated can also lead to death. Further, bacterial growth at the site of obstruction leads to microvascular changes that allow mesenteric lymph nodes translocation. The medical significance of SBO includes sepsis formation, wound dehiscence, abdominal abscess, short bowel syndrome, aspiration and even death due to delay in treatment (5).

Imaging Procedures Employed to Evaluate the Pathology

The plain radiography of flat and upright view is required in case SBO is suspected, however, this imaging process is applicable in the case of simple obstruction. Further, enteroclysis is required when plain radiography fails to detect SBO even in the presence of clinical symptoms. Enteroclysis confirms SBO in partial and complete blockages. Further, CT scan (computed tomography scanning) is employed when clinical conditions like pain, fever, tachycardia and leucocytosis occur in the patient (3).

Radiologic Features

The first and foremost identifyingthe  radiological feature of small bowel obstruction is an appearance of air-fluid small bowel that is visual in plain radiography (plain X-ray). Further, the appearance of colonic gas highlights incomplete obstruction rather than complete SBO. Plain radiographic also highlights the presence of foreign body like gallstones. However, in contrast, radiography, gastrografin bowel appears as an obstruction in the mid-small bowel. There is the appearance of third special fluid in the intestinal lumen. The simple SMO are normal in appearance whereas complex once are volvulus, ischemic bowel, closed-loop, and incarcerated hernias (3,5,6).

Treatment Options

There are both operative and non-operative treatment options as per the condition of SBO.

Non-Operative Treatments

Adhesions

A reduction in intraoperative trauma can minimise the adhesion formation in the peritoneal surfaces

Acute Postoperative Obstruction Intervention

These are basically postoperative conditions that arise after SBO surgeries including incisional pain and ileus formation. They require nursing management strategies for control

Malignant Tumour Treatment

Surgical resection is considered to be non-operative treatment for obstruction occurring due to tumour formation

Inflammatory Bowel Disease Management

The occurrence of inflammation is a sign of SBO formation, therefore, high-dose steroids, parenteral treatment, and bowel rest are non-operative processes to control inflammatory bowel disease. In case non-operative treatment is not functional than bowel resection, surgery, and stricturoplasty is employed for treatment (7)

Radiation Therapy

This involves as a non-operative treatment where acute radiation therapy is applied to SBO followed by steroids. If radiation therapy isn’t successful then surgical treatment is the only option.

Monitoring and Observation

The pulse rate, blood pressure, and turgor pressure, urine output measures regularly indicate the fluid status of the body. Therefore, proper measurement and observations help to monitor the severity of the disease.

Nasogastric Tube

This nasogastric tube is used for upper gastrointestinal decompression to avoid nausea, vomiting and bowel distension (8)

Analgesia

The medication is prescribed to relief the peritoneal irritation indications that are initial signs of bowel ischemia.

Fluid Replacement Therapy

There is a continuous loss of fluid due to vomiting and sequestration in initial stages of the disease. Therefore, fluid replacement therapy in for of isotonic fluid intake in litres is maintained to replace the fluid loss  (1, 2).

Operative Treatments

The laparoscopy is implemented as a safe and effective surgical option in case of severe conditions of small bowel obstruction. Surgery is an easy going process when only single adhesive band or a hernia is the cause of SBO but surgery is complex when dense adhesions produce SBO. The operative treatment is involved in the case of failure of non-operative management or treatment (9).

References

O’Connor DB, Winter DC. The role of laparoscopy in the management of acute small-bowel obstruction: a review of over 2,000 cases. Surgical endoscopy. 2012 Jan 1;26(1):12-7.

Maung AA, Johnson DC, Piper GL, Barbosa RR, Rowell SE, Bokhari F, Collins JN, Gordon JR, Ra JH, Kerwin AJ. Evaluation and management of small-bowel obstruction: an Eastern Association for the Surgery of Trauma practice management guideline. Journal of Trauma and Acute Care Surgery. 2012 Nov 1;73(5):S362-9.

Lee JM, Jung SE, Lee KY. Small-bowel obstruction caused by phytobezoar: MR imaging findings. American Journal of Roentgenology. 2012 Nov 23.

Bartels SA, Vlug MS, Hollmann MW, Dijkgraaf MG, Ubbink DT, Cense HA, van Wagensveld BA, Engel AF, Gerhards MF, Bemelman WA. Small bowel obstruction, incisional hernia and survival after laparoscopic and open colonic resection (LAFA study). British Journal of Surgery. 2014 Aug 1;101(9):1153-9.

Tierris I, Mavrantonis C, Stratoulias C, Panousis G, Mpetsou A, Kalochristianakis N. Laparoscopy for acute small bowel obstruction: indication or contraindication?. Surgical endoscopy. 2011 Feb 1;25(2):531-5.

Kirshtein B, Mizrahi S, Sinelnikov I, Lantsberg L. Abdominal cocoon as a rare cause of small bowel obstruction in an elderly man: report of a case and review of the literature. Indian Journal of Surgery. 2011 Jan 1;73(1):73-5.

Li, M. Z., Lian, L., Xiao, L. B., Wu, W. H., He, Y. L., & Song, X. M. (2012). Laparoscopic versus open adhesiolysis in patients with adhesive small bowel obstruction: a systematic review and meta-analysis. The American Journal of Surgery, 204(5), 779-786.

Maung, A. A., Johnson, D. C., Piper, G. L., Barbosa, R. R., Rowell, S. E., Bokhari, F., ... & Kerwin, A. J. (2012). Evaluation and management of small-bowel obstruction: an Eastern Association for the Surgery of Trauma practice management guideline. Journal of Trauma and Acute Care Surgery, 73(5), S362-S369.

Lee, J. M., Jung, S. E., & Lee, K. Y. (2012). Small-bowel obstruction caused by phytobezoar: MR imaging findings. American Journal of Roentgenology.