Malignant bowel obstruction is caused by luminal narrowing of the small or large bowel due to metastatic intra-abdominal cancer. The most common primary cancers are colorectal, ovarian, breast, and melanoma. Treatment aims to palliatively relieve symptoms like pain, nausea, and vomiting to improve quality of life, as cure is not possible. Both non-operative treatments like octreotide, opioids, antiemetics, and stenting as well as surgical options may be considered depending on the extent of malignancy and patient's condition. The goal is symptom control and allowing oral intake and return home if possible.

1. MALIGNANT BOWEL
OBSTRUCTION
BIN YUNUS
GENERAL SURGERY UNIT

2. DEFINITION
• Malignant bowel obstruction is defined as luminal narrowing of
small or large bowel with clinical evidence of bowel obstruction in
the setting of metastatic intra-abdominal cancer.

3. MOST COMMON CANCERS
• INTRA-ABDOMINAL
• Colorectal cancer
• Ovarian
• EXTRA-ABDOMINAL
• Breast cancer
• Melanoma

4. CLASSIFICATION
A. Mechanical
• Extrinsic
• Intrinsic
Adynamic (caused by tumour infiltrating bowel wall, nerve and
plexus)
B. Partial or complete
C. Proximal or distal

5. PATHOPHYSIOLOGIC MECHANISM
• Mechanical compression
• Motility disorder
• Gastrointestinal secretion accumulation
• Decrease intestinal absorption
• Peri-tumoral inflammation

6. PRESENTATION
• Gradual worsening of abdominal pain /distension
• Progressive worsening of nausea/vomiting
• Overflow diarrhea (bacteria overgrowth)

7. INVESTIGATIONS
1. PLAIN ABDOMINAL X-RAY;
• Multiple fluid level may be unremarkable because tumour
encasement of the bowel wall may prevent the classical sign of
bowel dilatation seen in non-maligant bowel obstruction.
2. Small bowel contrast
Using either barium or gastrograffin Opinions are divided on this. But
a failure of contrast to reach the caecum in 24 hours suggests high
grade or complete obstruction.
3. Ba Enema.
If this shows obstruction in addition with small bowel blockage this
suggests multiple levels of obstruction consistent with carcinomatosis

8. 4.Enteroclysis Studies.
• Duodenum is intubated directly under fluoroscopy and contrast
injected directly under pressure. Very reliable in showing sites and
degree of obstruction.
• This however needs an expert in this procedure
5.CT-Scan:
This is essential in all cases of MBO if surgical treatment is being
considered.
It is now the gold standard in diagnosing malignant bowel
obstruction

9. • Sensitivity of CT-Scan in the diagnosis of malignant bowel obstruction
= (78 –100%)
• Specificity = (> 90%)
• These will show the sites of obstruction, possible bowel strangulation
or ischaemia.

10. TREATMENT
• Realise this is end of life management, hence treatment is palliative to
improve the quality of life. No cure is expected, proper counseling of
patients and relatives. Increase in length of survival is bonus.
• About 15% of patients are terminally ill

11. PRIMARY GOAL OF TREATMENT
• Alleviate nausea, vomiting and pain
• Make patient to eat
• Return patient home or a nursing facility

12. NON-OPERATIVE TREATMENT
1. NASO-GASTRIC TUBE DRAINAGE ; Nasogastric tube This is very
uncomfortable. Used only on a time-limited basis for decompression.
2. IV FLUID; REHYDRATE.
3. NUTRITION; PARENTERAL
4. PHARMACOLOGICAL ; The goals are:
• Alleviate pain;
• Check nausea,
• Check vomoting,
• Intestinal inflammation and oedema

13. PHARMACOLOGICAL
1. OCTREOTIDE
• One of the most effective drugs for the relief of symptoms of MBO. It is a
synthetic analog of somatostantin. It reduces G. I. Secretions, increases small
bowel transit time, delays onset of oedema and ischaemia in anti-mesenteric
border of intestines. Effect can be dramatic. Within a few hours ! Response is
75 – 100%
• Dose: 0.3 – 0.6 mg/day sucut.
• Response is control of nausea and vomiting. Duration of treatment (Median
9.4 – 17.5 days).Relief period is for life of the patient

14. • 2. OPIODS
• A. Morphine and Hydromorphine
• Alleviate pain, produces adynamic ileus
• B. Methadone Very effective when used with metoclopramide
• C. Metoclopramide Some feel it is contraindicated in bowel
obstruction because it promotes gastric motility, but it is efficacious in
partial bowel obstruction.

15. • 3. ANTIEMETICS Oral medications should be avoided because of vomiting.
• A. Prochloperazine given rectally
• B. Promethazine given rectally
• C. Hydroxyzine given rectally
• D. Ondansetron given subcutaneously
• E,. Methotrimprazine given intramuscularly
• Haloperidol given subcutaneously.
• Haloperidol is believed to be the drug of choice, for it controls nausea, vomiting and
agitated delirium. With anti-emetics, complete relief of emesis is achieved in only
30% of patients.

16. • 4. ANTICHOLINERGICS
• They decrease peristalsis, secretions, vomiting and intestinal colic
• Scopolamine might be more cost effective than Octreotide. It is given subcut
or as a transdermal patch
• 5. CORTICOSTEROIDS
• This reduces peritumoral oedema,
• Activate central and peripheral anti-emetic effect
• It is co-analgesic in intestinal obstruction related pain.
Dexamethasone dose is 2 – 60mg per day. Usually prescribed for
terminal patients.

17. • 6.INTRA-PERITONEUM CHEMOTHERAPY can be used for recurrent
intra-abdominal carcinoma

18. SURGICAL TREATMENT
• Operative Mortality = ( 5 – 32%)
• Operative Morbidity = (42%)
• Re-obstruction = (10 – 50%)
• Therefore proper consideration must be given before performing
surgery. NO RUSH TO SURGERY.
• Obstruction usually partial
• Gangrenous bowel is rare

19. LESS LIKELY TO BENEFIT FROM SURGERY.
• Those with
• Ascites,
• Carcinomatosis,
• Abdominal mass that is palpable,
• Multiple obstruction,
• Very advanced carcinoma, and
• Those with very poor clinical status.

20. THE KREBS AND GOPLERUD PROGNOSTIC INDEX
• Palliation is regarded as successful if survival is at least 2 MONTHS
• This depends also on age, nutritional status, tumour status, ascites,
previous chemotherapy, and radiation treatment..

21. SURGICAL OPTIONS
The quickest and the safest is preferred
• RESECTION with or without anastomosis
• INTESTINAL BY-PASS especially for radiation-induced obstruction
• INTESTINAL STOMA, enterostomy, entero-colostomy,entero-
gastrostomy
• GASTROSTOMY is essentially for drainage to relieve nausea and
vomiting which are really very troublesome symptoms.

22. ENDOSCOPIC TREATMENT
• Usually for a single site obstruction
• Patients NOT fit for operation
• Extensive disease
• Patients refusing operation

23. • ENDOLUMINAL WALL STENTS
• Successful in 64 –100% in rectal carcinoma either complete or partial.
• In 70% of cases of upper intestinal obstruction, gastric outlet obstruction,duodenal
and jejunal obstructions.
• Expertise and necessary equipment are needed for this procedure
• The Procedure
• Canalise bowel using laser or ballon dilatation, insert a guide wire under fluoroscopy
(Seldinger’s technique to canalise the bowel. The neodymium-doped yttrium aluminium
garnet (Nd:YAG) laser can be used at the time of stenting for initial canalisation of bowel for
low rectal carcinoma, but not ideal for long term palliation
• Laser therapy requires repeated treatments to maintain luminal patency.
But balloon dilatation can be a short term measure at the time of stenting
or use of Nd:YAG laser. If stenting is possible it is probably the optimal
endoscopic technique.

24. • SEMS show success of about 90%. Show to maintain patency longer.
• Complications;
• Perforation
• Stent migration
• Stent obstruction

25. • PERCUTANEOUS ENDOSCOPIC GASTROSTOMY (PEG)
• Usually well tolerated
• Alleviate nausea and vomiting
• Allows intermittent oral intake.
• Patients with ascites are poor candidates for Percutaneous Endos
Gastrost. (PEG)

26. RADIOTHERAPY
• This is to produce local palliation to pelvis, duodenal area, and to
intestinal stoma blockages by tumor.
• Combination with 5-FU is beneficial
• Generally, complication of radiation will not occur before patient dies. This is
END OF LIFE (EOL) management/palliation.

27. CONCLUSION
• MBO is a common and difficult problem.
• Objectives are to relief pain, nausea,vomiting, early removal of N/G tube,
keep patient out of the hospital as much as possible and to restore ability to
eat.
• Non-surgical interventions should be considered in all patients.
• The decision to pursue surgical vs non-surgical treatment hinge on variety of
factors ; general patient condition and the extent of the malignancy.

28. REFERENCES
• 1. Prof. O. G. Ajao, Dept of Surgery, U. C. H. Ibadan, Nigeria. UPDATE
MATERIAL. WACS.
• 2. Sarah FH et ael. Malignant bowel obstruction. Expert analysis. 2015
• 3. Eric R, Charles F V. Current concept in malignant bowel obstruction
management. Curr Oncol. 2009; 11(4):293-303.