Welcome

Intestinal ObstructionBy Dr Praveen Choudhary

When there is pathological interference with the normal progression of the intestinal luminal contents distally, the condition is called intestinal obstruction.

Intestinal Obstruction

Etiology Intestinal obstruction may be classified

into two types:1.              Dynamic/Mechanical obstruction.2.              Adynamic obstruction. Dynamic/Mechanical Obstruction    I.Intraluminal (obstruction in the

human).  II.Intramural (lesion of bowel wall).III.Extramural (lesion extrinsic to the

bowel). Adynamic Obstruction      Peristalsis may be absent e.g. paralytic ileus. Peristalsis may be present in a non propulsive form.

Dynamic Obstruction        I.        Intraluminal Obstruction

a)   Meconium.b)  Bezoars: Ø   Trichobezoar. Ø   Phytobezoar.c)   Gall stones.d)  Polypoid Tumour of bowel.e)   Intussception.f)    Impaction of

barium/worms/foreign body.

Phytobezoar

Dynamic Obstruction I.      Intramural Obstruction

This can be classified into

(a)   Congenital

 (b)  Traumatic.

 (c)    Inflammatory

 (d)    Neoplastic

(e)   Miscellaneous

Meckel’s diverticulum

I.Extramural Obstruction:

(a) Adhesive band constriction

(b) External hernia

(c) Volvulus

(d)  Extrinsic masses

Dynamic Obstruction

Classification

Classification of Intestinal obstruction can be made as follow: -

1. Simple mechanical obstruction.

2. Strangulated obstruction.

3. Closed loop obstruction.

Clinical Classification

Clinically obstruction may be classified into two types:

1.      Small Bowel obstruction – high or low

2.      Large Bowel obstruction

Presentation

Presentation may be :-

1. Acute. 2. Chronic. 3. Acute on Chronic.4. Subacute.

Pathophysiology

Obstruction

Increased bowel motility

Relieve obstruction Does not relieve obstruction

Distension

Bacterial proliferation

Clinical Feature v  Pain.

 

v  Vomiting. 

v  Distension. 

v  Constipation.

Clinical Features Of Strangulation

v Shock

v Pain is never completely absent.

vThe presence and character of any local tenderness.

Distension

Late Manifestation

v Dehydration

v Oliguria

v Hypovolaemic shock

v Pyrexia

v Septicaemia

v Peritonism

v Respiratory embarrassment.

Examination

1. PHYSICAL EXAMINATION

(a) Inspection (b) Palpation(c) Percussion(d) Auscultation

2. Rectal Examination

Physical Examination Inspection

ØIn early stage ‘visible peristalsis is the only sign.Ø Abdominal distension is the late sign.ØHernial orfices, surgical scars must be inspected.

PalpationØDuring colic there may be muscle guarding. Slight tenderness may be present between attacks of pain. ØTenderness and rigidity at the sight of obstruction usually indicates strangulation.

PercussionOnly reveals resonant note of gaseous distension of bowel.

AuscultationØPresence of loud borborygmi, conciding with intestinal colic is very diagnostic.ØIn case of intestinal obstruction “Silent abdomen” suggests paralytic ileus.

Rectal Examination

Presence of mass on rectal examination within or outside the lumen will give a clue to diagnosis. Presence or absence of feaces in rectum should be noted. Absence means obstruction is higher up. If present it should be studied for presence of occult blood, which include mucosal lesion e.g. cancer, intussusception or infarction. Sigmoidoscopy should be done if colonic obstruction is suspected.

Special Investigation

(1)Blood Examination

(2) Radiological Examination

Management

There are three main measures: -1.           Gastrointestinal drainage.2.           Fluid and electrolyte replacement.3.           Relief of obstruction (surgical).

Supportive Management

Nasogastric Decompression Fluid And Electrolytic Replacement 

Antibiotics

Adhesions And BandsCause for Adhesions

1.Ischaemic areas2. Foreign material3. Infection & Inflammation 4. Radiation enteritis5. Drugs

Cause for BandsCongenitalA string band following previous bacterial peritonitis.A portion of greater omentum usually adherent to parictes.

Treatment Initial management of Adhesions And Bands is based on I.V. rehydration and nasogastric decompression.When obstruction is caused by an area of multiple adhesions, they should be freed by sharp dissection. To prevent recurrence the bare area should be covered with omental grafts.Following release of band obstruction, the constriction sites that have suffered direct compression should be carefully assessed

Recurrent Obstruction Due To Adhesion

Procedures are:Ø   Repeat adhesiolysis

(enterolysis) alone.Ø   Noble’s plication operation.Ø   Charles – Phillips transmesentric

plication.Ø   Intestinal intubation.

Special Types Of Obstruction

1. Internal Hernia

2. Obstruction From Enteric Strictures

3. Bolus Obstruction

4. Acute Intussusception

5. Volvulus

Internal Hernia

Internal herniation occurs where a portion of the small intestine becomes entrapped in one of the retroperitoneal fossae or into a congenital mesenteric defect.

Treatment : The standard treatment for a hernia is to release the constricting agent by division.

Enteric Strictures

Small bowel strictures usually occur secondary to tuberculosis or Crohn’s disease presentation is usually subacute or chronic.

Treatment : Standard surgical management consist of resection and anastomosis.

Bolus Obstruction Bolus obstruction in small bowel may be

caused by food, gallstone, Bezoars, stercolith and worms.

Treatment : In case of stone or food, after milking the stone proximally, crush the stone if possible. If not, the intestine is opened and the gallstone disimpacted, milked back and removed. In case of Bezoars or stercolith, Lesion may be kneaded, if possible otherwise open removal is required.

Acute Intussusception

When one portion of the gut invaginates into immediately adjacent loop, the condition is called intussusception

Types:(i)Primary(ii)Secondary

Intussusception

Treatment Preopertive Management

Nasogastric decompression.Intravenous rehydration.

Hydrostatic Reduction : Barium enema can be used for hydrostatic reduction of intussusception. Operative TreatmentAfter preoperative rescescitation a midline incision is used for proper exposure.Reduction is achieved by squeezing the most distal part. Cope,s method is used in difficult cases

V olvulus A volvulus is a twisting or axial rotation of a portion of bowel about its mesentry. When complete it forms a closed loop of obstruction with resultant ischemia secondary to vascular occlusionTwoTypes:1. Primary VolvulusCauses

1. Congential malrotationof gut.2. Abnormal mesentric attachments.3. Congential bands.

Example : Volvulus neonatorum, caecal & sigmoid volvulus. 2.Secondary VolvulusCause:Actual rotation of a piece of bowel around an acquired adhesion or stoma.

V olvulus

V olvulus Volvulus NeonatorumIt is predisposed to by arrested gut rotation with a resultant narrow mesentry of small bowel and caecum. Surgical TreatmentOperation consist of reduction by untwisting and division of any secondary obstructive lesions such as transduodenal band of ladd.

Volvulus of small intestineThis may be primary or secondary & usually occurs in lower ileum. Treatment: Treatment consist of reduction of the twist and is than directed to underlying cause.

V olvulus Caecal VolvulusMay occur as a part of volvulus neonatorum or denavo. Surgical TreatmentAt operation the volvulus should be reduced. Further management consist of either fixation of caecum to right iliac fossa(caecopaxy) or a caecostomy.

Sigmoid VolvulusIt occurs mainly due to band of adhesions. TreatmentFlexible sigmoidoscopy or rigid sigmoidoscopy and insertion of a flatus tube should be carried out to allow deflation of gut.

V olvulus Compound volvulusAlso known as ileosigmoid knotting. The long pelvic mesocolon allow the ileum to twist around the sigmoid colon resulting in gangrene of either or both segments of bowel. Surgery At operation decompression, resection and anastomosis are required.

Adynamic Obstruction Paralytic Ileus

It may be defined as a state in which there is failure of transmission of peristaltic waves secondary to neuromuscular failure.VarietesFollowing varieties are recognised :1.  Postoperative2.  Infection: Intra-abdominal sepsis

Ø   Localised ileus.Ø   Generalised ileus.

3.  Reflex ileus4.Matabolic: Uraemia & Hypokalaemia are commonest contributory factor.

ManagementThe essence of treatment is prevention with the use of nasogastric suction and restriction of the oral intake untill bowel sounds and passage of flatus return.Treatment is according to cause but following general principle apply:-1. Primary cause must be removed.2. Gastrointestinal distension must be relieved.3. Close attention to fluid and electrolyte balance is essential.4. Use of peristalsis stimulant is recommended only in ressistant cases.5. If paralytic ileus is prolonged, a laparotomy should be considered to exclude a hidden cause and facilitate bowel decompression.