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Youwillunderstand bynow thatinsomecircumstancesalaparotomy
forSBOwillbealonganddifficultoperationduetomultipleadhesionsor
radiation enteritis for example. If you begin an operation expecting a
quick and easy procedure and are then confronted by a nightmare
abdomenthefirstthingyoumustdoisresetyourmentalclock.Failureto
do this maymean that youwill attempt to rush the procedure and this
inevitably leads to disaster with multiple inadvertent enterotomies,
peritoneal contamination and ultimately an even longer and more
dangerous procedure. When you enter such a disastrous abdomen
unexpectedly,telleveryoneimmediatelythattheprocedureisnow
goingtotakeafewhourswhileyouunravelalltheloopsnecessary
togetattheproblem and fix it. And then take your timeand fix it
carefullyandslowly.
Laparoscopicapproach( Figure21.2)
2
Laparoscopic management of small bowel obstruction is a very
attractiveoptionforseveralreasons:
•
The actual maneuver needed in many cases is one snip of the
scissors, and subjecting the patient to a major laparotomy to
releaseasingleadhesivebandisapity!
•
Muchofthepost-laparotomyrecoveryisrelatedtoileuscreatedby
handling the already distended loops of bowel. Saving this
manipulation results, in my experience, in very swift recovery —
almost as if the obstruction was relieved spontaneously. You can
actually see the bowel contents propagate after you release the
obstruction,andperistalsisresumesunderyourlaparoscopicvision.
NG output quickly reduces, allowing early removal, early diet
resumption,andearlydischarge—asearlyaspostoperativeday1
insomesatisfyingcases.
•
Aseverylaparotomyinducesnewadhesionsandaddstotheriskof
future obstructions, it makes sense to try and avoid such added
insult. Laparoscopy induces very little adhesions, although it still
needs to be proven whether laparoscopic adhesiolysis indeed
reducestheincidenceoffutureobstructionepisodes.
The above mentioned advantages should be carefully weighed
against the potential risks. This procedure requires advanced
laparoscopicskills! Therisk forbowelinjury, anduncontrolled spillage
of bowel contents from the obstructedbowel, canresult insevere, and
evenlethalsepsis.
Figure21.2.Assistant:“Sir,permissiontotrylaparoscopically?WhereshouldIinsertthe
firsttrocar?”Chief:“Idiot!ThisisaclassicalcaseforSILS!”
Shouldyouwishto attemptalaparoscopicapproachdoitselectively
ontheeasiercases:
•
FirstepisodeofSBO.
•
Abdomennotexcessivelydistended(e.g.moreproximalSBO).
•
Patient stable and able to endure a prolonged pneumoperitoneum
—superimposedonanalreadydistendedabdomen.
Afewtechnicaltips:
•
Thefirstportshouldbeplacedthroughanopenapproachandaway
fromtheoldincision.
•
Try to work on the collapsed distal bowel, and find your way
‘backwards’,untilyouidentifytheobstructionsite.
•
Try to handle the mesentery and not the bowel wall itself; a little
mesentericlacerationisbetterthanunintendedperforation.
•
Moveslowly,andusetabletiltingandgravitytohelpyouwithbowel
mobilization and retraction — especially of the heavy, fluid-filled
obstructedloops.
Mostimportantly—donotbeobstinate;knowwhento abort —
beforeyoucreatetoomanyholes.
Acommentaboutdealingwithinterloopadhesionslaparoscopically.Ihatetryingtodividethem
and have had missed enterotomies. So if required I just convert. Maybe I am not as good a
laparoscopistasothers.Jon
Specialcircumstances
Thevirginabdomen
Patients presenting with SBO, but without a previous history of
abdominal surgery need special attention: it is here that you have to
suspect non-adhesive causes of SBO, including rare ‘zebra-like’
conditions, for example, the one and only obstructing obturator hernia
you are likely to diagnose and treat duringyour entire glorious surgical
career.
Sothepatientpresentswithclinicalandradiologicalfeaturesof
SBObut withnoabdominalwallscarofprevioussurgery.Whatto
do?
First, ask again about all past procedures including that laparoscopic ovarian
cystectomyandatinyscarhiddenintheumbilicus;andwhileyou’reatit,whydon’tyou
re-examinethegroinforincarceratedhernias!
IntheolddaysacompleteSBOinascarlessabdomenwasalwaysan
indicationforalaparotomy.Butnowdays,aCT(useGastrografin®!)isthe
way to go — mainly to rule out situations when an operation can be
avoided;forexample,SBOduetopreviouslyundiagnosedbutsuspected
Crohn’sdisease( Chapter26)orbolusobstructions(seebelow).
There is an endless list of potential causes of non-adhesive
mechnicalSBO, whichincludes abdominal wall hernias (the ones you
have missed on examination), malignancies (e.g. cecal tumors),
inflammatory masses (e.g. ‘lost’ gallstones), internal hernias (e.g.
foramenof Winslow hernia), bolus obstruction(e.g.gallstoneileus) and
so forth. There is no point pondering too much; just get the CT and
proceed with laparotomy/laparoscopy if indicated. In such cases there
isnoplaceforatrialofnon-operativemanagement.
Intussusception
Althoughcommoninpediatricpatients( Chapter36),intussusception
is a very rare cause of SBO in adults. In adults, the ‘leading point’ is
usually organic (e.g. neoplasm, inflammatory lesions), and seldom
idiopathic as in children. Patients with small bowel or ileocolic
intussusception present with non-specific features of SBO (in a virgin
abdomen) necessitating operative treatment. A specific pre-operative
diagnosis can be obtained with ultrasound or CT, showing the multiple
concentric ring sign (bowel within bowel), but won’t change what you
need to do — operate and resect the involved segment of bowel.
Althoughcontroversial,somewouldattemptreductionofintussusception
whentherearenoexternalsignsof ischemiaor malignancyand ifafter
reductionnoleadingpoint is found (i.e. idiopathic intussusception), one
could leave the bowel alone. Also, ‘partial’ reduction, if the
intussusceptionislong, maylimittheextentof resectiontothebowelin
thevicinityoftheleadingpoint,savingsomelengthofhealthybowel.
One more thing: you should differentiate between intussusception as a cause for obstruction
and that which is an incidental finding on a CT scan. The latter is harmless, intermittent,
physiological, and does not require intervention — despite the pressure to ‘fix it’. Just make
surethereisnoleadingpointseenbyagoodquality‘enterography’CT.Ifyousuccumbtothat
pressure (“laparoscopy is harmless, just have a look to make sure…”) you may find yourself
searching in vain, and then open (“just to make sure by palpation…”), and even resect an
innocentsegment.Danny
Theknowncancerpatient
ApatientisadmittedwithSBOayearortwofollowinganoperationfor
gastric or colonic or ovarian cancer. You should first attempt to obtain
information about the findings at the previous laparotomy. The more
advanced the cancer, the higher the probability that the current
obstruction is malignant. Clinically, cachexia, ascites or an abdominal
masssuggest diffusecarcinomatosis.These cases present a medical
and ethical dilemma. On the one hand, one wishes to relieve the
obstructionandofferthepatientafurtherspellofqualitylife.Ontheother
hand, one tries to spare a terminal patient an unnecessary operation.
Eachcaseshouldbe assessed on merit. In the absence of stigmata of
advanceddisease,surgeryforcompleteobstructionisjustifiable.Inmany
instances adhesions may be found; in others, a bowel segment
obstructed by local spread or metastases can be bypassed. When
diffuse carcinomatosis is suspected clinically or on CT scan, a
reasonable option would be to insert a palliative, venting
percutaneousgastrostomy,allowingthepatienttodrink,andtodie
peacefullyathomeorinahospiceenvironment.
A sincere, ongoing discussion with the patient, his family, and his
oncologist is crucial to finding the optimal balance between ‘cure’,
palliationandfutilecare.
Indoubtfulcases,itmaybebettertooperateandfindend-stagecarcinomatosisthanto
missanobstructionthatcanbereadilyfixed.
Radiationenteritis
SBO following radiation treatment of abdominal or pelvic
malignancyusuallydevelopsmonthsorevenyearsafterirradiation.
A relentless course of multiple episodes of partial SBO, initially
responding to conservative treatment but eventually culminating in a
complete obstruction, is characteristic. There is also the uncertainty
abouttheobstructionbeingmalignantoradhesiveinnature.Onealways
hopes that it is adhesive, because SBO due to radiation injury is ‘bad
news’indeed.
When forced to operate for complete obstruction, one finds
irradiated loops of bowel glued or welded together and onto
adjacent structures. The paper-thin bowel tears easily. Accidental
enterotomies are frequent, difficult to repair, and commonly result in
postoperative fistulas. Short involved segments of bowel are best
resected, but when longer segments are encountered, usually stuck in
the pelvis, it is safest to bail out with an entero-enteric or enterocolic
bypass,usingnon-irradiatedbowelforthispurpose.Postoperativeshortbowel syndrome is common whatever the procedure. Long-term
prognosis is poor — radiation enteritis is almost as bad as the
malignancytheradiationhadattemptedtocontrol.
RecurrentmultipleepisodesofSBO
The patient istypicallyreadmitted every secondmonth for SBO
and has undergone, in the past, multiple operations for this
condition.Howshouldhebemanaged?
We would treat him as any other patient presenting with adhesive
SBO. Fortunately, most such episodes are ‘partial’, and responsive to
conservativetreatment.Whencompleteobstructiondevelops,operative
managementisobviouslynecessary.Attemptsatpreventingsubsequent
episodeswithplicationofbowel or mesentery or long tube stenting are
recommended by some. The evidence in favor of such maneuvers is
anecdotal at best. We do not practice them. Occasionally a patient
developsobstruction earlyin theaftermath ofan operationfor adhesive
SBO: this is a case par excellence for prolonged non-operative
management,withthepatientmaintainedonTPNuntiladhesionsmature
andtheobstructionresolves(see Chapter45).
Inourexperience,mostsuch‘frequentSBOtravelers’knowhow
to treat their episodes of obstruction better than the resident (or
surgeon)on call. Listento whatthey havetosay. They knowthat
noteveryepisoderequiresaCT!
Commonly,oneisaskedbypatientsortheirphysiciansto performan
elective adhesiolysis in order to prevent further episodes of adhesive
SBO.Thissoundstemptingofcourse.Butanyonewhohastrieddoingso
knowsthatevenafteracompleteandmostsatisfyingadhesiolysisthese
patientscanreturnwiththesameproblem.Ouradvice:operateonlyfor
non-resolvingSBO—prophylacticsurgerydoesnotwork.
Gallstoneileus
Gallstoneileusdevelopstypicallyin elderlypatientswithlongstanding
cholelithiasis.It is caused by a large gallstoneerodingintoan adjacent
segmentofbowel—usuallytheduodenum—andthenmigratingdistally
until stuck in the narrow ileum. Presentation is usually vague as
initially the stone may disimpact spontaneously — causing
intermittentepisodesofpartialobstruction.
You will never miss the diagnosis once you habitually and
obsessivelysearchforair inthebile ductsonanyplainabdominal
X-ray you order (or on the CT). The air enters the bile duct via the
enterocholecysticfistulacreatedbytheerodinggallstone(stillremember
thedifferentialdiagnosisofpneumobilia?Ifnotgobackto Chapter5).
Treatmentisoperativeandshouldbetailoredtotheconditionof
thepatient. In frail andsick patientsdeal only with theSBO: place an
enterotomyproximaltothestoneandremoveitandsearchforadditional
stonesinthebowel above — you do not want to have to reoperate! In
patientswho are youngerand reasonably fitand well, youmaywant to
also deal with the cause of the problem — the gallbladder. Perform a
cholecystectomy and close the duodenal defect: place your suture line
transversely to avoid narrowing of the duodenum. But again: not
removing the gallbladder after dealing with the obstructing
gallstoneisaperfectlyreasonableoption.
And some of us think that this is by far the better option. Any large gallstones still in the
gallbladder can usually be removed easily by cholecystotomy and then simply close the
gallbladderagain—mucheasierandsaferthancholecystectomyinthissituation.Paul
You can also look at the situation as nature’s solution to the gallbladder disease. After
spontaneouslydrainingitselfintothebowelitislesslikelytocausefurtherproblems.Danny
Bezoars
Bezoarsaretightlypackedcollections,or‘balls’,ofpartiallydigestedor
undigested material forming inthe stomach and thenmigrating distally,
wherethey may obstruct theterminalileum. You mayencounterone of
thefollowingtypesofbezoars:
•
Phytobezoars: partially digested agglomerations of vegetables or
fruits forming in patients with altered gastric physiology (e.g.
followinggastricresection,vagotomyorbariatricoperationandeven
in patients with diabetic gastroparesis) or health food aficionados,
andelderly ‘forget-to-chewers’. Manysortsof fruits and vegetables
areimplicated,particularlywhenconsumedinlargequantity(Moshe
oncesufferedpartialSBOafterconsuming,withinanhour,awhole
bagof baby carrots;large quantitiesofpopcorn cando thesame),
butconsumptionofpersimmonsisespeciallynotoriousinthisregard
—withpatientsdevelopingmultipleepisodesofSBO.
•
Trichobezoars: most commonly occurring in youngerpatientswith
psychiatric disturbances who chew and swallow their own hair.
Trichobezoars form in the stomach and often reach a huge size;
they break into smaller pieces and migrate into the small bowel
wheretheycanobstructatseveralpoints.
•
Parasiticbezoars:consistingofconglomeratesofparasitessuchas
Ascaris lumbricoides which may obstruct the distal ileum. This is
obviouslycommoninendemicareas.
Patients present usually with features of partial or ‘smoldering’
SBOandavirginabdomen.History is suggestive, and CTimages —
showingtheactualintraluminalbezoars—arediagnostic.Asmentioned
above,aGastrografin®challengecandislodgetheobstructingparasites,
or other types ofbezoars, pushingthem into the cecum. Butwhen the
obstruction is complete, you have to operate and deal with the
obstructingbezoarlikeyoudowiththegallstone(seeabove).However,
some bezoars can sometimes be fragmented, and milked on,
withouttheneedforenterotomy.Itiscrucialtopalpatetheentiresmall
bowel, including the duodenum (and also the stomach) for additional
bezoars,andremove allofthem.Indeed,intra-operativegastroscopy
is recommended to remove the ‘mother bezoar’ before new
fragmentsarepassedon.Pre-operativeCTmaybehelpfulinmapping
suchadditionalbezoarsforyou.Youdon’twantthepatienttodevelop
earlypostoperativeSBO—causedbyamissedbezoar— needing
anotherlaparotomyforremoval,doyou?
Forbezoarsaftergastrectomy, we consider the use ofmeattenderizerspriortosurgery—to
breakitup.Jon
SBOaftergastrectomy
Withthedisappearanceofgastrectomyperformedforbenigndisease,
and the declining rate of gastric cancer, there are not too many postgastrectomypatientstopresentwithSBO,althoughsomedo.However,
with the mushrooming of bariatric gastric surgery, this entity has
becomerelevantagain.
According to our friends Professor David Dent (Cape Town, South
Africa) and Dr. Hernan Diaz (Santiago, Chile) — both of them ‘old
gastrectomists’—thereasonsforSBOinthesepatientsare:
•
Simpleadhesiveobstruction—what’scommoniscommon!(See
above.)
•
Recurrent gastric carcinoma, with loops of bowel ‘frozen’ by
peritonealcarcinomatosis(seeabove).
•
Bolusobstructionbybezoars(seeabove).
•
Internal herniation of small bowel through defects of the
mesocolonorbehindthejejunalloopformingtheBillrothII(orRouxen-Y)gastroenterostomy—beitantecolicorretrocolic.
•
Twistingorvolvulusofredundantafferentorefferentjejunalloops.
•
Another specific type of obstruction is the jejunogastric
intussusception.Boththeafferentorefferentloopscaninvaginate
into the gastric remnant but the retrograde efferent loop
intussusceptionismorecommon.Thiscanoccurfromafewdaysup
to many years after the gastrectomy. Sudden onset of epigastric
pain,vomitingandhematemesis,andapalpableepigastricmassin
apatientwithpreviousgastricsurgeryaretheclassictriad.
•
Obstruction of the afferent loop after Billroth II or Roux-en-Y
reconstruction—bywhicheveroftheabovementionedmechanisms
— produces a closed loop obstruction (between the obstructing
point and the duodenal stump). High intraluminal pressures are
commonly associated withelevation of serum pancreatic enzymes
(amylase)and,iftheobstructionisnotrelieved,withnecrosisofthe
involvedloop and theattached duodenum. Theclinicalpictureof
epigastric pain, upper abdominal mass and hyperamylasemia
mayconfuseyouintothinkingthatyouaredealingwith acute
pancreatitis.
Obviously, the more complex the original post-gastrectomy
reconstruction, the more potential peritoneal defects created, and the
‘looser’thevariousintestinalloops—thehighertheriskforboweltokink,
rotate,herniateandobstruct.(NowyouunderstandwhywepreferBillroth
Ireconstructionaftergastrectomy!)
The proximal location of the obstruction is suggested by the
frequent vomiting, lack of abdominal distension and paucity of
dilatedsmallbowelonplainabdominalX-ray.CTwithoralcontrastis
asuperb diagnosticaid,showing theexact anatomy ofobstruction, and
the ‘ring sign’ of small bowel within the stomach in the case of
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