BOWEL OBSTRUCTIONBy,

DR.SRINIVASAN RAMAN

Tbilisi state medical university.

BOWEL OBSTRUCTION OVERVIEW

CLASSIFICATION COMMON CAUSES OF OBSTRUCTION CLINICAL FEATURES INVESTIGATION TREATMENT

INTRODUCTION

Accounts for 5% of all acute surgical admissions Patients are often extremely ill requiring prompt assessment,

resuscitation and intensive monitoring Types: Obstruction: A mechanical blockage arising from a structural abnormality that

presents a physical barrier to the progression of gut contents.

Ileus: is a paralytic or functional variety of obstruction Obstruction is: Partial or complete Simple or strangulated

CLASSIFICATION

Result from atony of the intestine with loss of normal peristalsis, in the absence of a mechanical cause.

or it may be present in a non-propulsive form (e.g. mesenteric vascular occlusion or pseudo-obstruction)

ADYNAMIC(FUNCTIONAL)

Result from atony of the intestine with loss of normal peristalsis, in the absence of a mechanical cause.

or it may be present in a non-propulsive form (e.g. mesenteric vascular occlusion or pseudo-obstruction)

ADYNAMIC(FUNCTIONAL)

TYPES OF BOWEL OBSTRUCTION

TYPES AND CAUSES OF DYNAMIC OBSTRUCTION

Intraluminal• Impaction• Foreign bodies• Bezoars• Gallstone

Intramural• Congenital atresia• Stricture• Malignancy(15%)

Extramural• Bands/

adhesion(40%)• Hernia (12%)• Volvulus• Intussusception• Tumor-benign/

malignant

Peritoneal irritation local fibrin production produces adhesions between apposed surfaces

As early as 4 weeks post laparotomy. The majority of patients present between 1-5 years

Colorectal Surgery 25%Gynaecological 20%Appendectomy 14%

Prevention: good surgical technique, washing of the peritoneal cavity with saline to remove clots, etc, minimizing contact w/ gauze, covering anastomosis & raw peritoneal surfaces

TREATMENT OF ADHESIVE OBSTRUCTION

Initially treat conservatively provided there is no signs of strangulation; should rarely continue conservative treatment for longer than 72 hours

At operation, divide only the causative adhesion and limit dissection

Laparoscopic adhesiolysis in cases of chronic subacute obstruction

Hernia Accounts for 20% of SBO

Commonest 1. Femoral hernia

2. ID inguinal

3. Umbilical

4. Others: incisional

The site of obstruction is the neck of hernia

The compromised viscus is with in the sac.

Ischaemia occurs initially by venous occlusion, followed by oedema and arterial compromise.

Attempt to distinguish the difference between: Incarceration

Sliding

Obstruction

Strangulation is noted by: Persistent pain

Discolouration

Tenderness

Constitutional symptoms

Volvulus

A twisting or axial rotation of a portion of bowel about its mesentery. When complete it forms a closed loop obstruction ischemia

Commonest spontaneous type in adult is sigmoid, can be relieved by decompression per anum

Surgery is required to prevent or relieve ischaemia

Features: palpable tympanic lump (sausage shape) in the midline or left side of abdomen. Constipation, abdominal distension (early & progressive)

ACUTE INTUSSUSEPTIONOccurs when one portion of the gut becomes invaginated within an immediately adjacent segment.

Common in 1st year of life

Common after viral illness enlargement of Peyer’s patches

Ileocolic is the commonest variety in child.

Colocolic intussusception commonest in adult

An intussusception is composed of three parts : the entering or inner tube; the returning or middle tube; the sheath or outer tube (intussuscipiens).

Classically, a previously healthy infant presents with colicky pain and vomiting (milk then bile).

Between episodes the child initially appears well.

Later, they may pass a ‘redcurrant jelly’ stool.

LARGE BOWEL OBSTRUCTION

Distinguishing ileus from mechanical obstruction is challenging

Caecum is at the greatest risk of perforation

Perforation results in the release of formed feaces with heavy bacterial contamination

Aetiology:

1. Carcinoma:

The commonest cause, 18% of colonic ca. present with obstruction

2. Benign stricture:

Due to Diverticular disease, Ischemia, Inflammatory bowel disease.

3. Volvulus:

-Sigmoid Volvulus/ Caecal Volvulus

4. Hernia.

5. Congenital : HirschPrung, anal stenosis and agenesis

CLINICAL FEATURES

Large bowel obstructiondistension is early and pronounced.

Pain is mild and vomiting and dehydration are late.

The proximal colon and caecum are distended on abdominal radiography

CARDINAL FEATURES: Colicky painVomitingAbd distentionConstipation

OTHER FEATURES: DehydrationHypokalaemiaPyrexiaAbd tenderness

PHYSICAL EXAMINATION

INSPECTION

Abdominal distention, scars, visible peristalsis.

PALPATION

Mass, tenderness, guarding

PERCUSSION

Tymphanic, dullness

AUSCULTATION

Bowel sound are high pitch and increase in frequency

INVESTIGATIONS:

Lab: FBC (leukocytosis, anaemia, hematocrit, platelets) Clotting profile Arterial blood gasses U& Crt, Na, K, Amylase, LFT and glucose, LDH Group and save (x-match if needed) Optional (ESR, CRP, Hepatitis profile)

RadiOlogical: Plain ABDOMINAL xrays USS ( free fluid, masses, mucosal folds, pattern of paristalsis,

Doppler of mesenteric vasulature, solid organs) Other advanced studies (CT, MRI, Contrast studieS)

Fluid levels with gas above; ‘stepladder pattern’. Ileal obstruction by adhesions; patient erect.

 Supine radiograph from a patient with complete small bowel obstruction shows distended small bowel loops in the central abdomen with prominent valvulae conniventes (small white arrow)

 Figure 3. Lateral decubitus view of the abdomen, showing air-fluid levels consistent with intestinal obstruction (arrows).

In small bowel

Central 3cm thick diameter

Vulvulae coniventae

Ileum may occur tubeless

In large bowel

Peripheral diameter 6cm

Presence of haustration

ROLE OF CT

Used with iv contrast, oral and rectal contrast (triple contrast).

Able to demonstrate abnormality in the bowel wall, mesentery, mesenteric vessels and peritoneum.

It can define:

the level of obstruction

The degree of obstruction

The cause: volvulus, hernia, luminal and mural causes

The degree of ischaemia

Free fluid and gas

Ensure: patient vitally stable with no renal failure and no previous alergy to iodine

• FIGURE: AXIAL COMPUTED TOMOGRAPHY SCAN SHOWING DILATED, CONTRAST-FILLED LOOPS OF BOWEL ON THE PATIENT’S LEFT (YELLOW ARROWS), WITH DECOMPRESSED DISTAL SMALL BOWEL ON THE PATIENT’S RIGHT (RED ARROWS). THE CAUSE OF OBSTRUCTION, AN INCARCERATED UMBILICAL HERNIA, CAN ALSO BE SEEN (GREEN ARROW), WITH PROXIMALLY DILATED BOWEL ENTERING THE HERNIA AND DECOMPRESSED BOWEL EXITING THE HERNIA.

CONTRAST STUDIES

Barium should not be used in a patient with peritonitis

As: follow through, enema

Limited use in the acute setting

Gastrografin is used in acute abdomen but is diluted

Useful in recurrent and chronic obstruction

May able to define the level and mural causes.

Can be used to distinguish adynamic and mechanical obstruction

TREATMENT OF INTESTINAL OBSTRUCTION Supportive

1. Resuscitation

2. Ryle tube free flow with 4 hourly aspiration

-Decompression of proximal to the obstruction, reduce subsequent aspiration during induction of anesthesia and post extubation.

3. IV drip normal saline / Hartmann (Sodium & water loss during IO)

4. Broad spectrum antibiotic (not mandatory but need in all patient undergoing surgery.

MANAGEMENT FOR LARGE BOWEL OBSTRUCTION

All patients require•Adequate resuscitation•Prophylactic antibiotics•Consenting and marking for potential stoma formation

•At operation•Full laparotomy should be performed•Liver should be palpated for metastases•Colon should be inspected for synchronous tumours

•Appropriate operations include:•Right sided lesions – right hemicolectomy•Transverse colonic lesion – extended right hemicolectomy•Left sided lesions – various options

INDICATIONS FOR SURGERY

Generalised peritonitis

Localised peritonitis

Visceral perforation

Irreducible hernia

Palpable mass lesion

Failure to improve

Advanced malignancy

Incomplete obstruction

Advanced malignancy

SURGERYThree-staged procedure Defunctioning colostomy Resection and anastomosis Closure of colostomy

Two-staged procedure Hartmann’s procedure: the

surgical resection of the rectosigmoid colon with closure of the rectal stump and formation of an end colostomy. It was used to treat colon cancer or diverticulitis

Closure of colostomy

Complications associated with intestinal obstruction repair

include excessive bleeding

infection

formation of abscesses (pockets of pus)

leakage of stool from an anastomosis

adhesion formation

paralytic ileus (temporary paralysis of the intestines)

reoccurrence of the obstruction.

PARALYTIC ILEUS

A state in which there is a failure of transmission of peristaltic waves 2° to neuromuscular failure ( in Auerbach’s and Meissner’s plexuses)

Stasis leads to accumulation of fluid and gas within bowel a/w distension, vomiting, absence of bowel sound and absolute constipation

Varieties factors: postoperative, infection, reflex ileus and metabolic

Radiological: gas filled loops of intestines with multiple fluid levels

Management:

Essence of treatment prevention with use of nasogastric suction and restriction of oral intake until bowel sound and passage of flatus return

Maintain electrolyte balance Specific treatment:

Removed primary cause

Decompressed GI distension

If prolong paralytic ileus , consider laparotomy exclude hidden cause and facilitate bowel decompression

REFERENCE

http://emedicine.medscape.com/article/930576-overview#aw2aab6b2b4

http://www.patient.co.uk/doctor/intestinal-obstruction-and-ileus

https://www.youtube.com

https://en.wikipedia.org/wiki/Bowel_obstruction

http://www.webmd.com/digestive-disorders/tc/bowel-obstruction-topic-overview

http://www.mayoclinic.org/diseases-conditions/intestinal-obstruction/basics/symptoms/con-20027567