Upper embolization

In general, arterial thrombi are platelet-rich ( white clots ) and form at ruptured atherosclerotic plaques, leading to intraluminal occlusion of arteries that can result in end-organ injury (e.g., myocardial infarction, stroke). In contrast, venous thrombi consist mainly of fibrin and red blood cells ( red clots ), and usually form in low-flow veins of the limbs, producing deep vein thrombosis (DVT) the major threat to life results when lower extremity (and, occasionally, upper extremity) venous thrombi embolize via the right heart chambers into the pulmonary arteries, i.e., pulmonary embolism (PE). 

Instruct the patient regarding nonpharmacologic strategies including elevation of the affected extremity and anti-embolic exercises such as flexion/extension of the ankle (for lower extremity VTE) or hand squeezing/relaxation (for upper extremity VTE). 

These potential benefits are balanced by a slightly increased risk of gallbladder disease, hypertension, myocardial infarction, cerebral infarction, and pulmonary embolism. The increased risk of stroke and heart attack associated with the pill is accentuated when compounded by other risk factors, including smoking, migraine headaches, and advancing age. Indeed, convincing data support an upper age limit of 35 years for oral contraceptive use by women who smoke. 

Fig. 4.14. Maps of the apparent diffusion coefficient (ADC) measured before and after embolic occlusion of the right middle cerebral artery in an animal without therapy (upper row) and in two animals with thrombolytic treatment initiated 1.5 h (middle row) and 4.5 h (lower row) after onset of ischemia. In the untreated animal, a decline of ADC was observed immediately after MCA occlusion that increased in size over time. Thrombolysis with recombinant tissue-type plasminogen activator (tPA) lead to the partial reversal of the ADC lesion over the first 5 h of therapy if started early. Late-onset thrombolysis at 4.5 h post occlusion did not reverse lesion growth, but was followed by a further lesion enlargement of the ischemic lesion. [Reproduced with permission from Hoehn et al. (2001)]...

Fig. 4.15. Perfusion images (PI) and spectroscopic imaging maps of lactate and N-acetyl-aspartate (NAA) before and after embolic occlusion of the middle cerebral artery. Thrombolysis was applied 1.5 h after embolism and lead to a partial reperfusion of the affected territory (upper row). There was a clear increase in lactate that was partially reversed upon thrombolytic reperfusion. NAA maps showed a decreased signal in the ischemic hemisphere that did not recover. [Reproduced with permission from Franke et al. (2000)]...

Embolism from thrombus within the cavity of an aneurysm is rare and is difficult to prove in cases where there maybe other potential sources of embolization. Intracranial aneurysms more commonly present with rupture and subarachnoid hemorrhage, whereas internal carotid artery aneurysms tend to cause pressure symptoms including a pulsatile and sometimes painful mass in the neck or pharynx, ipsilateral Horner s syndrome or compression of the lower cranial nerves. Extracranial vertebral artery aneurysms may cause pain in the neck and arm, a mass, spinal cord compression and upper limb ischemia (Catala et al. 1993). 

Figure 15. Uniform layer of platelets and fibrin (lower half of picture) on a2-macroglobulin-coated Silastic after 5 min of blood contact. Thrombi (upper center) are in the process of embolization. Embolization probably has occurred in upper center of the micrograph.

Supraduodenal artery - This vessel provides blood supply to the upper portion of the duodenum and pylorus [2]. The origin of this vessel is also variable, and it communicates with the pancreaticoduodenal arcade as well as right gastric branches [7]. If identified, this vessel should be prophylactically embolized. 

Therapeutic vasopressin infusion into the main arterial trunks induces visceral vasospasm, enhancing the physiological vasoconstrictive reaction against bleeding. Initial enthusiasm about vasopressin infusion ebbed away because of less favorable results compared to embolization [79-81], and the systemic side effects [82]. Vasopressin infusion has been shown more effective in lower than in upper GIH. 

Table 5.2. Contrast extravasation/aneurysm in upper GIH technique of embolization according to vascular anatomy...

Table 5.3. Embolic agents, mechanism of occlusive action and applicability in upper GIH ...

Embolic agents/ embolisation technique Mechanical proximal occlusion Mechanical distal occlusion Flow dependent distal occlusion Endo- saccular occlusion Applicability in upper GIH... 

Table 5.4. Cookbook Properties of catheters and guidewires used in upper GIH embolization...

The mortality rate after embolization for refractory upper GIH varies between 25%-35% [7, 8, 10, 51]. Mortality is associated with underlying disease, multi-organ failure and rebleeding after embolization. ScHENKER et al. [8] calculated that patients with a clinically successful embolization were 13.3 times more likely to survive, independently of their clinical condition. 

Transcatheter embolization has the potential to further reduce mortality in acute non-variceal upper GIH, provided we continue our efforts to optimize the occlusive technique and enhance the haemostatic effect. Furthermore, increasing angiographic sensitivity, which in our opinion depends much on the alertness of the involved endoscopist, will reduce the need for non-targeted blind embolization. Whether transcatheter techniques can replace surgical salvage in upper GIH remains to be established by prospective randomized studies. 

Katzen BT, McSweeney J (1975) Therapeutic transluminal arterial embolization for bleeding in the upper part of the gastrointestinal tract. Surg Gynecol Obstet 141 523-527... 

Reuter SR, Chuang VP, Bree RL (1975) Selective arterial embolization for control of massive upper gastrointestinal bleeding. Am J Roentgenol Radium Ther Nucl Med 125 119-126... 

Goldman ML, Land WC, Bradley EL, et al. (1976) Transcatheter therapeutic embolization in the management of massive upper gastrointestinal bleeding. Radiology 120 513-521... 

Castaneda-Zuniga WR, Jauregui H, Rysavy J, et al. (1978) Selective transcatheter embolization of the upper gastrointestinal tract an experimental study. Radiology 127 81-83... 

Lang EV, Picus D, Marx MV, et al. (1992) Massive upper gastrointestinal hemorrhage with normal findings on arteriography value of prophylactic embolization of the... 

Fig. 7.3a,b. Hepatic arteriogram in a 26-year-old man with a small inoperable neuroendocrine tumour in the head of his pancreas. The papilla of Vater could not be accessed at ERCP and he underwent a percutaneous stenting procedure at which two self-expanding stents were inserted (lower arrowheads) apparently side by side (a). 12 hours later repeat ERCP revealed a significant haemorrhage from the papilla. The angiogram revealed a segment 4 arterial pseudoaneurysm (upper arrowheads) which was embolized successfully with coils (b)... 

Fig. 17.15. a CT performed 6 months after embolization of a complex PAVM of the right upper lobe shows recanalization of the feeding artery (arrow) due to insufficient packing. The draining vein is still opacified (V). b Selective injection of the feeding artery confirms recanalization (arrow). Additional embolization has been performed to obtain complete cross-sectional occlusion... 

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