International surgical boards

2022-03-13 00:17:15 Fogarty catheter

This is a very important instrument in vascular surgery used for embolectomy.

In acute limb ischaemia, through a groin incision the femoral artery is elevated by slings, and a longitudinal or transverse arteriotomy is made, for removal of clots distal or proximal to the arteriotomy site, a Fogarty catheter is inserted until it is deemed to have passed beyond the clot, whereby the balloon tip is inflated (see figure above) and the catheter is slowly withdrawn dragging the clot with it to enable extraction of the clot via the arteriotomy, bleeding from the arteriotomy site indicates clearance of the clot from the involved vessel.

Complications include vessel perforation with hematoma formation, False aneurysm, intimal tears with arterial dissection, uncommonly the balloon tip is disconnected. Open / Comment

2022-03-12 16:20:25 Fontaine classification and the ankle brachial pressure index

Fontaine classification is used to stratify the severity of an underlying lower limb arterial disease as follows:

Fontaine I = Asymptomatic.
Fontaine IIa = Intermittent claudication at a distance greater than 200 meters.
Fontaine IIb = Intermittent claudications at distance less than 200 meters.
Fontaine III = Rest pain.
Fontaine IV = Ulceration and gangrene.

Ankle brachial pressure index (ABPI) is used to detect and quantify degree of arterial insufficiency, it is the ratio of systolic pressure at the ankle (posterior tibial or dorsalis pedis which ever is higher) and at brachial artery, the normal ratio is 0.9 to 1.3, ratio less than 0.9 indicate diseased arteries, less than 0.3 indicate imminent necrosis.

Exercising the patient leads to dilatation of vascular spaces distal to an obstruction, if the feeding vessel is diseased it cannot keep pace with increased vascular space and thus ABPI will drop furthur. Open / Comment

2022-03-12 16:03:50 Answer

A1: Para-esophageal (Rolling) hiatus hernia, the chest x ray reveals the shadow of the stomach behind the heart, with disappearance of the gas bubble at its normal site.

A2: CT scan with oral contrast gives more accurate details than barium meal in trendelenburg position, as CT can also reveal the contents of the hernial sac such as small bowel or colon in addition to the stomach.

A3: Operative treatment is nearly always advised, as these herniae are dangerous and liable for strangulation, gangrene and perforation unlike the sliding variety. Open / Comment

2022-03-02 01:12:45 Cancer and inflammatory bowel disease

Both ulcerative colitis and Crohn's colitis seem to increase the risk of colorectal cancer, the risk for ulcerative colitis is about 20% in 30 years period, the risk seems lower for Crohn's colitis.

The most important factor increasing risk of cancer is longstanding extensive and uncontrolled disease.

Those that have UC with concomitant primary sclerosing cholangitis seem to have a greater risk for colorectal cancer, the cause is unknown.

After 10 years of diagnosis, follow up for development of dysplasia should be done, This was done by endoscopy, taking biopsies every 10 cm, but this means that lesion can be missed, so this is unacceptable, the new technique is pancolonic chromoendoscopy.

Pancolonic chromoendoscopy include targeted biopsies of abnormal areas detected by staining, this include methylene blue and indigo carmine, above fig shows the procedure, A is before stain, and B is after it, showing a lesion which was biopsied and showed dysplasia. Open / Comment

2022-03-02 01:12:45 For revision Open / Comment

2022-03-01 18:52:46 Colonic angiodysplasia

These are dilated, thin walled, tortous submucosal veins related to ageing, mostly in those over 60 years.

Histologically the vein has very thin muscle coat, it is weak and liable to bleed, in most cases this is chronic bleeding causing anemia, occasionally massive bleeding culminating in hypovolemic shock is seen.

This condition is strongly associated with aortic stenosis, this is called Heyde syndrome, it is also associated with vascular malformations in skin and oral mucosa in Hereditary hemorrhagic telangiectasia.

It can be diagnosed by colonoscopy (see above fig) and dealt with by colonoscopic diathermy or argon laser, if massive bleeding is present surgery is needed with on table colonoscopy to detect the site of bleeding, if this is not possible colectomy may be done.

Barium enema is avoided, it is unhelpful and can mask the lesions on subsequent colonoscopy, selective mesenteric angiography can at times detect these lesions. Open / Comment

2022-03-01 18:00:28 Open / Comment

2022-03-01 03:05:17 Chylolymphatic mesenteric cyst

This is the most common mesenteric cyst, and it is caused by lymphatic malformation in which part of the lymphatic tissue in the mesentery fails to connect with the lymphatic system, simply it has no efferent connections.

The cyst has thin wall lined by flat endothelium, almost always single and is usually unilocular and most commonly arise in the mesenetry of the ileum, it often contain clear lymph, but may contain chyle which can be watery, or thick like a cream.

Chylolymphatic cysts has their own independant blood supply, they DO NOT share the blood supply with the adjacent intestinal loop so they can be enucleated without resection of the associated loop of intestine.

Fig above shows a giant chylolymphatic cyst. Open / Comment

2022-03-01 01:37:15 Open / Comment

2022-03-01 00:07:50 Open / Comment