This document discusses the pathology and management of malignant bowel obstruction. It defines malignant bowel obstruction as luminal narrowing of the small or large bowel due to metastatic cancer. The most common primary cancers causing MBO are colorectal, ovarian, stomach, and pancreatic cancers. The document outlines the classification, signs and symptoms, diagnostic tests including CT scan, and various treatment options for MBO, including surgical resection, endoscopic stenting, non-operative management with medications like octreotide to relieve symptoms, and palliative care since MBO represents terminal cancer. The primary goals of treatment are palliation to improve quality of life by relieving nausea, vomiting and pain.

1. 60 year old male with malignant
bowel obstruction.
Discuss the pathology and
management of malignant bowel
obstruction.
By
Dr Olofin. K. E
Senior registrar
General surgery unit
National hospital

2. Outline
• Introduction
• Definition
• Epidemiology
• Etiology
• Classification
• Pathology
• Management
• History
• Physical examination
• Investigation
• Treatment
• Conclusion
• References

3. Introduction
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.

4. • According to Report of the Clinical Protocol
Committee: the following diagnostic criteria were
made
1. clinical evidence of bowel obstruction
2. obstruction distal to the Treitz ligament
3. the presence of primary intra-abdominal or extra-
abdominal cancer with peritoneal involvement
4. the absence of reasonable possibilities for a cure

5. Introduction
Epidemiology
• The global prevalence rate is estimated to range from 3% to 15%
of cancer patients
• Primary cancers of abdominal origin that most frequently
produce MBO are those of the
• colon 25%–40%
• ovary 16%–29%
• stomach 6%–19%
• pancreas 6%–13%
• bladder 3%–10%
• endometrium 3%–11%
• Those of extra-abdominal origin due to peritoneal infiltration are
those of the
• breast 2%–3%
• melanoma 3%
• The mean age at presentation is 61 years (from 58–65 years)

6. Introduction
Aetiology
• Intra-abdominal
• Colorectal cancer
• Ovarian
• Extra-abdominal
• Breast cancer
• Melanoma

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

8. Pathology
Factors directly related to intra-abdominal tumor
growth
• Extrinsic intestinal compression:
• Mesenteric and omental tumor involvement may
angulate the bowel and provoke extramural bowel
occlusion
• Endoluminal intestinal obstruction:
• Intraluminal tumors may occlude the bowel lumen or
provoke intussusception

9. • Intramural intestinal infiltration:
• Intramural infiltration through the mucosa may obstruct
the lumen or impair peristaltic movements.
• Infiltration of the mesenteries and plexus:
• Infiltration of the enteric or celiac plexus may cause
severe impairment in peristalsis and consequent
obstruction due to dysmotility

10. • Factors not directly related to intra-abdominal
tumor growth
• Paraneoplastic neuropathy
• Opioid-induced intestinal dysfunction: Chronic
constipation
• Adynamic ileum Inflammatory intestinal disease
• Renal insufficiency/dehydratation
• Mesenteric thrombosis
• Postsurgical adherences
• Radiogenic fibrosis

11. Management
History
• nausea 100%
• vomiting 87%–100%
• colic pain 72%–80%
• pain due to distension 56%–90%
• Absolute constipation in the previous 72 hours in
85%–93%
• Overflow diarrhea (bacteria overgrowth)

12. Management
Physical examination
Anthropometry, vitals, Pallor, Jaundice, hydration
status
Abdomen:
Size, tenderness, masses, ascites organomegaly,
bowel sounds
DRE: masses

13. Investigations
• Plain abdominal x-ray;
• Dilated loop of bowel
• Multiple air fluid level
• Gasless pelvis
• Ground glass appearance
• In some cases, Multiple air/fluid level may be unremarkable
because tumour encasement of the bowel wall may prevent
the classical sign of bowel dilatation seen in non-malignant
bowel obstruction.
• 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.

14. • Barium enema.
• If this shows obstruction in addition with small bowel
blockage this suggests multiple levels of obstruction
consistent with carcinomatosis
• 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

15. • 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.
• MRI

16. • FBC
• E/U
• LFT
• Clotting profile
•

17. Management
Treatment
• The decision making process in advanced oncologic
patients requires individualized evaluation based
on
• the extension of the neoplasm
• the global prognosis
• the possibility of specific cancer treatments
• associated comorbidities
• the general status
• the particular options available to the duly informed
patient

18. Management
Treatment
• Realize 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

19. Management
• Primary goal of treatment
• Alleviate nausea, vomiting and pain
• Make patient able to eat
• Return patient home or a nursing facility

20. • Possible treatments include
• Surgery
• endoscopic palliation
• digestive aspiration
• symptomatic palliative pharmacologic therapy

21. 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.

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

23. 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.

24. 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.

25. Endoscopic treatment
• Usually for a single site obstruction
• Patients NOT fit for operation
• Extensive disease
• Patients refusing operation

26. 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

27. • The procedure
• Canalize bowel using laser or balloon dilatation.
• insert a guide wire under fluoroscopy (seldinger's technique
to canalize the bowel. The neodymium-doped yttrium
aluminium garnet (nd:yag) laser can be used at the time of
stenting for initial canalization of bowel for tow rectal
carcinoma
• 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.

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

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

30. Non-operative treatment
• Naso-gastric tube drainage
• It is very discomforting.
• Used only on a time-limited basis for decompression.
• IV fluid; rehydrate.
• Nutrition; parenteral
• Pharmacological; the goals are:
• Alleviate pain
• Check nausea
• Check vomiting
• Intestinal inflammation and oedema

31. Pharmacological
• Octreotide
• One of the most effective drugs for the relief of symptoms of
MBO.
• It is a synthetic analog of somatostatin.
• 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 subcutaneous route.
• Response is control of nausea and vomiting.
• Duration of treatment (median 9.4-17.5 days).
• Relief period is for life of the patient

32. • Opioids
• Morphine and hydromorphine
• Alleviate pain, produces adynamic ileus
• Methadone very effective when used with
metoclopramide
• Metoclopramide
• some feel it is contraindicated in bowel obstruction because it
promotes gastric motility, but it is efficacious in partial bowel
obstruction.

33. • Antiemetics
• oral medications should be avoided because of
vomiting.
• Prochloperazine given rectally
• Promethazine given rectally
• Hydroxyzine given rectally
• Ondansetron given subcutaneously
• 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.

34. • Anticholinergics
• They decrease peristalsis, secretions, vomiting and
intestinal colic
• Scopolamine:
• might be more cost effective than octreotide.
• It is given subcutaneously or as a transdermal patch

35. Corticosteroids
• This reduces peri-tumoral 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.

36. Intra-peritoneum chemotherapy
• Can be used for recurrent Intra-abdominal carcinoma

37. Management
• 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.

38. 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.

39. References
• Albert Tuca, Ernest Guell, Emilio Martinez-Losada,
Nuria Codorniu. Malignant bowel obstruction in
advanced cancer patients: epidemiology, management,
and factors influencing spontaneous resolution: Cancer
Management and Research 2012:4 159–169
• Prof. O. G. Ajao, Dept of Surgery, U. C. H. Ibadan,
Nigeria. Update material. Wacs.
• Sarah FH et ael. Malignant bowel obstruction. Expert
analysis. 2015
• Eric R, Charles F V. Current concept in malignant bowel
obstruction management. Current Oncology. 2009;
11(4):293-303.

40. •Thank you