Surgical Management of the GI Tract Flashcards
LO:
- Intestinal disorders: Describe the clinical features and treatment options of small and large intestine disorders
Surgical Management of the GI Tract – Case 1
anorexic-loss of appetite
No evidence of ascites-as no evidence of free fluid
He is 84, so prostrate isn’t alarming
This scenario is typical of an acute intestinal obstruction.
Which would be more likely in this case, obstruction of the small or large bowel?
No evidence of previous op-mentioned before, commonest cause of small bowel obstruction was peritoneal adhesions caused by abdominal surgeries. Hernias are second commonest
No vomiting-If small bowel obstruction-all fluid coming from stomach, liver and pancreas will back up quickly, but in large bowel obstruction, fluid can go through small bowel and start to be absorbed and so vomiting is less common and presents late and tends to be faecal.
Grossly distended-large bowel can distend bigger than small bowel.
What does the ABX demonstrate & what is the likely diagnosis?
In any intestinal obstruction-first put down NGT
Usually only do supine xrays on the right here
Can see fluid level on erect abx, fluid goes down and air goes up, so that all points towards this being an obstruction
Coffee bean sign-specific for bowel obstruction
Small bowel-will see lines going across whole width of bowel, but here lines only go partly across.
What conservative management is effective in treating the majority of patients with a sigmoid volvulus?
here is diagram of sigmoid volvulus. Sigmoid colon twists on itself like an animal balloon. Closed loop causes massive distension-can see it looks like a coffee bean.
-soft rubber rectal tube=flatus tube
Rigid sigmoidocscope goes via rectum and can reach as far as sigmoid
Push to where volvulus is and then suddenly get a release of flatus and liquid faeces. Can be done on ward or in A and E.
What is the risk of leaving this untreated?
Left untreated, the closed loop of sigmoid, with its blood supply cut off by the torsion, would undergo necrosis.
With twist have twisted mesenetery too, so is real emergency.
What is the next step in managing this patient?
Black lines are mesenteric blood vessels so when twist these twist too and venous vessels are blocked first and this causes oedema in bowel and this then effects arterial vessels. Flatus tube gets through twist and is usually successful in 80% of patients.
Have to resect dead bowel, can’t leave it-sigmoid colectomy. If do sigmoid colectomy have a join but this is at a high risk of falling to pieces as people are weak and malnourished and so can end up with faeces inside them, so most people would just to and end colonoscopy (hartmann’s procedure shown in pic).
Commonest is sigmoid volvulus and second commonest is caecal volvulus but even small bowel can volve rarely.
Flatus tube, if doesnt work
Flexible sigmoidoscopy, if doesnt work
exploratory laparascopy and end colonectomy-by this point bowel might have died so have to resect it.
Surgical Management of the GI Tract – Case 2
BP-slightly down
Peri-around
Not unusual to go for laparascopic procedures and hernia is noted, which is a much lesser procedure, so always check hernia orifices.
Investigations:
Hb down and WCC is up, urea and creatinine are up confirming suspection of him being dehydrated
He has a lactic acidosis (form of metabolic acidosis)
plain abdominal x-ray
Clinical scenario is suspicious for acute mesenteric ischemia (AMI).
Why?
- Increased risk of CVD especially atherosclerosis, when flow becomes turbulent get risk of something clotting and that increases
- Quick onset
- central abdominal pain so pointing towards ischaemia
- assuming not small bowel obstruction as no abnormal scar or hernia and no bowel sounds (would have tinkling in sbo)
- serum lactate is late sign of ischaemia in bowel
What investigation would you order next & why?
dual phase CT scan-where you see arteries and veins
If expecting ischaemic bowel would do dual phase as want to see arteries and veins, so if have clear pics will be able to see if thrombus or embolus there.
If it is an embolus, it means something is firing this off so may see splenic infacts so this will help see infarcts f other organs.
Spine at back, black is air on outside, black of right is air in bowel. Can tell this is arterial phase as aorta is white so full of contrast. Can see normal flow in SMA as it is enhancing same as aorta where the blood is coming from.
next is further down slice of body as lower down slice of kidney. Again SMA normal flow as can see contrast in it
Even further down as looking at bottom slice of kidneys. Here SMA suddenly disappeared so suggests embolus (thrown off from something else) or thrombus (coagulation insitu)
Coronal view from head to toe. Middle colic goes to transverse colon, distal to this can see no contrast. Due to obstruction in SMA.
Here is same CT coming towards pelvis, abnormal bowel as we can see fluid line, but can also tell bowel is not enhancing. Here it looks slightly grey as contrast is getting to it, as white around it so arterial supply is getting there but on other it there isn’t so it is ischaemic.
How would you manage this patient?
-Remove dead bowel as will die if this is left in
Exploratory Laparotomy
Endovascular management Aims
- Relief of acute symptoms with restoration of venous patency
- prevention of clot propagation and subsequent pulmonary embolism,
clot lysis through the use of catheter-directed thrombolytic therapy
Mostly done via midline as gives access to all quadrants of abdomen. Need to examine all organs and bowels to check nothing else is dead. Often just staple bowels up and leave in discontinuity as often will be back 24 hours later to relook at bowel as more bits might be dead so don’t join up nicely straight away.
Try and restore blood flow to ischaemic tissue-embolectomy-blow balloon up and pull it out to get rid of thrombus and blood flow will be restored. Endovascular-rather than using a ballon to remove, use a catheter and inject thrombolytic to try and dissolve clot, this is done percutaneously through an artery to get into the SMA.
Extensive mesenteric ischaemia causing small bowel necrosis:
Left-very advanced-here has serosa, but sausage bit shows serosa has died here too.
right- Dead bowel smells ghastly so you can tell in open laparotomy. Here although dilated, it looks healthy as pink. In back bit can see patches which show it is threatened by iscahemia and so may not be healthy, this is why you check 24 hours later as more bowel may have died.
Acute Mesenteric Ischaemia (AMI)Case 2
Arterial:
Atrial fibrillation-can get little clots in left auricle and can clot in SMA. Thombus tends to affect larger vessels but emboli are broken off so are smaller and so tend to affect distal more smaller arteries.
Very rare is left atrial myxoma-cancer of heart, small bit can break off and lodge in arterial system.
Thrombosis is less common-but effects more catastrophic as blocking origin of SMA so causes ischaemia of full bowel as blocking trunk of tree not just branch like in emboli.
Rarely can get nonocclusive mesenteric ischaemia. Not uncommon when patients are put on cardiac bypass for cardiac surgery-often get ischaemic bowel.
Vasopressin supplements-cause constriction so can cause iscahemia
Venous
Portal hypertension-back flow pressure as slow flow through liver so more likely to become coagulated and cause a thrombus
Portal pyaemia-It may develop as a complication of intra-abdominal sepsis, such as diverticulitis or appendicitis. Bugs flow through portal system through liver and this can make blood coagulated
Sickle cell-increases occlusion clotting due to shape of
Hypercoagulable states: Obesity, pregnant, on oral contraceptive pill, certain cancers eg pancreatic cancer
