Stents and Lasers fo r Co lo no sco pic Lesio ns
Douglas G. Adler, MD and Todd H. Baron, MD
Address
D epar tment of Medicine, D ivision of Gastroenterology and H epatology,
Mayo Medical Center, Eisenberg 8A, 200 First Street SW ,
Rochester, MN 55905, USA.
E-mail:baron.todd@ mayo.edu
Current Gastroenterology Reports 2000, 2:399–405
Current Science Inc. ISSN 1522–8037
Copyright © 2000 by Current Science Inc.
Introduction
Recent developments in endoscopic therapy have led to
several major advances in the treatment of colonic disease.
Some of the most exciting breakthroughs have been in the
realm of endoscopic stenting. Although the past 10 years
saw an explosion of interest in esophageal, biliary, and
pancreatic stenting, it seems that the nascent field of
colonic stenting is now gathering momentum. Colonic
stenting of benign and malignant strictures, once thought
impractical, is now proving itself to be a valid, and some-
times life-saving, technique. This review focuses primarily
on the use of expandable metal stents in the colon, includ-
ing their indications, uses, risks, and benefits. Attention is
also given to several new uses for laser therapy in the treat-
ment of colonic disease, both as an independent therapeu-
tic modality and as a tool to be used in certain situations
alongside colonic stenting. With this article, the authors
hope to give the reader an overview of the state of endo-
scopic stent and laser therapy for colonic disease.
Colonoscopic Stents and Colonic Obstruction
Colonic obstruction
More than 150,000 deaths occur worldwide each year from
colorectal cancer. Despite aggressive screening and surveil-
lance incentives in the United States and abroad, total or
near-total colonic obstruction is still a very common
scenario for the presentation of colorectal cancer. Various
studies have shown that between 8% and 29% of patients
will have colonic obstruction at the time of disease discov-
ery [1•]. It has been known for some time that colonic
obstruction caused by malignancy accounts for as much as
85% of surgical large bowel emergencies, making it the
number one cause of emergency large bowel surgery [2,3•].
Indeed, up to one half of all splenic flexure tumors and
one quarter of all left-sided tumors present as obstruction
[1•]. Fortunately, rectosigmoid cancers, the most common
subtype, present with obstruction in only 6% of cases,
largely due to the wider lumen in that region of the bowel
[1•]. Other, less common, causes of large bowel obstruc-
tion include diverticulitis, strictures from prior radiation
therapy, anastomotic strictures, or extrinsic compression
from adjacent tumors, both benign and malignant.
Patients with colonic obstruction are often severely
dehydrated, largely due to their inability to take fluids
orally. Those with malignancy are also frequently malnour-
ished, due to their underlying disease state [4•]. Patients
with primary colorectal cancer who present with obstruc-
tion frequently harbor advanced malignancies; nearly all
have Duke’s stage C or D disease [5]. These factors com-
bine to make this group of patients, who are o ften badly in
need of surgical decompression, poor candidates for an
emergency surgical procedure. In addition, these patients
almo st universally lack proper bowel preparation and have
friable bowel tissue due to the obstruction itself, making
them very poor candidates for surgery [4•]. Although
figures vary, typical rates for surgical mortality from acute
large bowel obstruction are in the range of 15% [1•].
Overview of surgical options for
large bowel obstruction
An appreciatio n o f the surgical o ptio ns available to patients
with acute or subacute colonic obstruction is critical to
understanding the potential impact that stents can have in
the management of these patients. Early surgical treatment
of colonic obstruction involved a “three-stage” operation.
In the first stage, a decompressing colostomy was
constructed. The second stage involved resection of the
primary lesion, and the final stage re-anastomosed the
remaining bowel and resulted in colostomy closure. Often,
the first two stages were do ne at the same ho spitalizatio n as
separate surgeries. This resulted in lo ng ho spital stays, o ften
greater than 30 days. Up to one quarter of patients treated
The use of self-expanding metal stents (SEMS) in the colon is
now becoming more commonplace. These devices can be
employed to decompress large bowel that has become
obstructed from either benign or malignant disease. Many
studies in the past year have validated the use of colonic
SEMS to allow preoperative bowel preparation in resectable
patients, or as an alternative to surgery in those requiring
palliative therapy alone. Laser therapy has also gained new
ground in recent months because it has been shown to help
in recanulation of obstructed bowel to aid in SEMS placement.
In addition, laser therapy alone can be used to treat some
colonic lesions that had formerly been treated surgically.