The aim of this study was to evaluate the potential for intravenous vasopressin to reduce the risk of nontarget gastrointestinal embolization during transcatheter liver-directed cancer therapies in a porcine model.

An angiographic catheter was used to select the celiac or common hepatic artery under fluoroscopic guidance in six anesthetized pigs. After angiography of the hepatic and splanchnic territories was performed, technetium-99m macroaggregated albumin ((99m)Tc-MAA) was injected through the catheter. Serial arteriograms were obtained before, every 5 minutes during, and after peripheral intravenous vasopressin infusion at 0.4 U/min for a minimum of 20 minutes. After 10 minutes of infusion, indium-111 ((111)In)-MAA was injected through the arterial catheter. Quantitative comparisons of liver and gastrointestinal activity using dual-isotope single-photon emission computed tomography (SPECT)/CT imaging were performed.

Catheter angiography demonstrated reduced blood flow to the splanchnic vasculature while maintaining blood flow through the hepatic arteries during vasopressin infusion. Angiographic findings correlated with the relative distribution of (99m)Tc-MAA (before the vasopressin infusion) and (111)In-MAA (after the vasopressin infusion) on SPECT/CT. The increased ratio of liver to gastrointestinal tract activity during the vasopressin infusion was statistically significant (6.2:11.4, respectively; P = .018).

Intravenous vasopressin reduces arterial blood flow to the splanchnic vasculature while preserving hepatic arterial blood flow in a healthy porcine model. Intraprocedural vasopressin administration has the potential to benefit liver-directed cancer therapies by enhancing tumor targeting as well as preventing the unintended delivery of bland embolic, chemoembolic, or radioembolic agents into the gastrointestinal vascular territories.

Variceal bleeding in cirrhosis can cause liver ischaemia and deteriorate the hyperdynamic state; thus, the effects of vasoconstrictor therapy on liver blood volume (LBV) and thorax blood volume (ThBV) are important.

To evaluate and compare the effects of terlipressin and somatostatin on LBV and ThBV in stable patients with cirrhosis and portal hypertension.

Twenty patients were studied (Child-Pugh class A/B/C: 5/8/7). The radioactivities in the liver region (LRR) and the thorax region (ThRR) by single-head gamma camera technique, as indicators of LBV and ThBV, respectively, and systemic haemodynamics were measured at baseline and after intravenous infusion of 2 mg of terlipressin (n=10) or somatostatin 250 mg/h after an initial bolus of 250 mg (n=10).

LRR and ThRR decreased significantly with increasing severity of cirrhosis. Thirty minutes after terlipressin infusion, LRR and ThRR increased by 7.8 ± 4.4% (NS) and 14 ± 5.3% (P=0.01) compared with baseline values; the increase in ThRR was significantly related to the increase in LRR (r=0.682, P=0.03). In contrast, somatostatin reduced LRR and ThRR by 13.3 ± 6.5% (P=0.07) and 1 ± 4% (NS) respectively. LRR and ThRR increased significantly in the terlipressin group compared with the somatostatin group (P=0.01 and P=0.02 respectively). Terlipressin reduced cardiac output and heart rate (both P=0.01) and increased the mean arterial pressure (MAP) and systemic vascular resistance (P=0.009 and P=0.002 respectively); MAP decreased after somatostatin infusion (P=0.03).

Terlipressin, but not somatostatin, maintains LBV, increases ThBV and improves the hyperdynamic state in cirrhosis. These effects can be beneficial in variceal bleeding, particularly in patients with advanced liver disease.

Diagnostic angiography still plays an essential role in the diagnosis of patients,particularly those with acute lower GI bleeding. Transcatheter therapy appears to be a viable treatment alternative in selected patients with GI bleeding. Many interventionists today believe embolotherapy to be more effective initially and to have better long-term results, specifically less rebleeding, than vasopressin infusion with at least equal complication rates. Unfortunately, direct comparison of the two techniques in a randomized, controlled fashion has not been performed. Small patient series, such as those summarized here, suggest that the results of the two techniques are essentially equal, and ischemic complications appear more prevalent with embolotherapy. The use of embolotherapy--either empirically based on endoscopic or surgical findings or directed against a site found to have contrast extravasation-represents the current intervention of choice in the case of upper GI bleeding refractory to endoscopic intervention. Head-to-head studies directly comparing the efficacy, morbidity, and mortality associated with endovascular or surgical correction of bleeding from the upper GI tract is needed. Although the current tide favors embolotherapy in the lower GI tract, infusion of vasoconstricting agents deserves more attention. To that end, there is a great need for scientific data regarding the safety and efficacy of transcatheter therapy for upper and lower GI bleeding.

Vasopressin administered as a bolus immediately before selective visceral angiography increased the information obtained in hepatic and pancreatic disease. The drug may be helpful in differentiating between inflammatory and malignant lesions in the intestines.

Visceral angiography was performed in 7 patients with normal portal pressure and in 10 with portal hypertension. Circulation times, size of vessels and portal pressure were determined. At celiac angiography a direct correlation was found between time for maximum filling of portal vein and portal pressure, provided no vascular abnormalities existed. At superior mesenteric angiography such a correlation was not found; loss of flow by shunts in portal hypertension being one explanation. Portocaval shunts are common in the celiac system, but uncommon in the superior mesenteric system.

Angiotensin in a dose of 0.5 to 1.0 microgran injected into the renal artery of healthy kidneys initially decreased renal blood flow and increased the appearance time and mean transit time of dye and contrast medium as examined by a dye dilution technique and angiography. The initial phase is followed by a reactive hyperemia. The increased vascular resistance is probably localized peripherally on the arterial side of the vascular tree. Optimum dose is 0.5 to 1.0 microgram angiotensin in diagnosis of renal tumours. Optimum interval between drug administration and angiography is 10 to 60 s.

Of 21 patients with cirrhosis of the liver 9 had collateral arterial flow to the liver from the superior mesenteric artery. The degree of collateral arterial flow in cirrhosis was related to the presence of centrifugal portal flow, the degree of bilirubinemia and the presence of a markedly enlarged spleen with increased splenic blood flow. Of 27 non-cirrhotic 6 had collateral arterial flow to the liver from the superior mesenteric artery. The greatest degree of collateral arterial flow was associated with celiac stenosis in 4/6 patients. One patient had pancreatitis and an explanation was not evident in one patient.