CLINICALSCIENCES CASE REPORTS Local ColloidTrapping in the Liverin the InferiorVena Cava Syndrome Max S. Lin, James W. Fletcher, and Robert M. Donati Veterans Administration Medical Center and St. Louis University, St. Louis, Missouri Local radioactiveareas In the liver were observedas a resultof superficialca voportal shunting of radiocolloids in two patients with the inferIor vena cava syn drome.in one patienta paraumbllicaland/or a recanalizedumbilicalveinwas ap parently involvedin the hepatopetalshunting.In the other patient a superficial anastomosisother than the paraumbilicalvein shuntedcolloidto the liver. Rela tivelydiscreteareasof IncreasedradioactivIty,singleor multiple,were seeninthe left lobe. Virtuallyall reportedinstancesof hepatopetalshuntingof radloparticles in a superioror an inferiorvena cava syndromehave demonstratedsimilarfind ings.Varioushepatopetalcollateral pathwaysIn Infrarenalcaval obstructionare considered,and factorsthat couldaffect liver scan findingsIn the infrarenalob structionare discussed. J NucI Med 22: 344—346,1981 In the superior vena cava (SVC) syndrome, radiocolloid liver showed extensive pelvic collaterals with nonfilling of the right scansmay showan areaof increasedactivity in the left lobeof the common ilica vein and retrograde filling of the left external iliac organ. At least 26 casesof focal colloid liver concentration have vein. He was treated conservatively with anticoagulants. been reported in the literature through 1979 (1—14).The accu One month later, he wasreadmitted becauseof a grosshema mulated data suggestthat the area is produced by collaterally tuna. Cystoscopy showed blood coming from the right ureter. An shuntedcolloids. A paraumbilical vein or a dilated umbilical vein intravenouspyelogramand an abdominal sonogramwerenormal, has been mentioned as a last leg in the hepatopetal collateral although the latter failed to visualize the IVC. A Tc-99m sulfur journey following administration of radioparticles to an upper colloid study was obtained following a deliberate administration extremity. Analogous areasof increaseduptake should occur in in the right leg. The colloid arrived in the left lobe through what an inferior vena cava (IVC) syndrome if the colloid is given appeared to be a paraumbilical vein and produced multiple focal through a legvein. In this communication,wereport two suchcases increased concentrations in the lobe (Fig. 1). The hematuria was and review related observationsin the literature. ascribed to the anticoagulant and did not recur after the drug was discontinued. Case 2. A 58-year-old man was admitted for evaluation of lower CASE REPORTS abdominal pain. Pasthistory included resectionofa colonic ade CaseI. A 47-year-old man presentedwith edemaofboth lower nocarcinoma 2 yr before admission, and a briefepisode of severe extremities and a long history of right-leg swelling and right-groin edemaof both lowerextremitiesandgroins I .5yr beforeadmission. varicosity. Two weeksbefore admission,he noted aggravation of Physical examination on admission showed a scaphoid abdomen the legswelling and for the first time developedswelling in the left with prominent veins and surgical scars, but with no palpable mass. leg. Inspection of the abdomenshowedprominent veinsover the Edemawasabsentin all extremities.Urinalysis wasnormal. Figure 2 shows a Tc-99m SC study obtained after admission. With no epigastrium and both lower quadrants, with a midline scar from suitable veins in the arms, the colloid was administered through a prior umbilical herniorrhaphy. Urinalysis, SMA-12, and chest a leg vein. A hepatopetal shunting occurred, producing an area of radiographs were all normal. A right-leg contrast venogram increased uptake in the quadrate area of the left lobe. The obser vation indicated an IVC syndrome, which had escaped recognition Received Sept. I 8, 1980; revision accepted Dec. 5, 1980. until then. Subsequentlywe learned that he had had a sulfur-col For reprints contact: Max S. Lin, MD, PhD, Nuclear Medicine bid scintigram I I mo before the admission; difficulty was en Service( I ISiC), VA Medical Center,St. Louis, MO 63I25. countered with intravenous administration, and the colloid had 344 THE JOURNAL OF NUCLEAR MEDICINE CLINICALSCIENCES CASEREPORTS FIG.1. Superficialhepatopetalcollaterals andfocal areasof activfty in liver(Case 1). Tc-99m sulfur colloid (3 mCi) was admin Isteredthrougha right leg vein. Shownare @ eight consecutive dynamic frames (8 A t: +@#1/)@)e sec/frame, beginning 17th second after injection) and anterior and right lateral static images.Notecephaladflow in visu alized right inferior epigastric vein, sub I I sequentvisualizationof paaumbllical vein, nonuniform uptake in left lobe, and non visualizationof Inferior vena cava. beeninjected into a femoral artery. Although initially interpreted syndrome (1—14).Only in a few colloid studies (4) doesthe left as normal, upon review the scintigram indicated an interruption lobe,asidefrom focal areasof uptake, look generally more active of the IVC at a high infrarenal level without visible collateral or than the right one.The presentCase2 is an example of such cx localized liver uptake. ceptions (Fig. 2). Hepatopetal shunting of Ic-99m albumin mi crospheres has been observed by others in two cases of IVC syn DISCUSSION drome (10,20). In both cases,a singleareaof mi@resphereuptake wasseenwithin but not over the entire region of the left lobe. In both cases,the IVC syndromeappearedto be due to an in Even if shuntedcolloid enters through the paraumbilical vein frarenal IVC obstruction. There was no nephrotic syndrome or into the left main branch of the portal vein in an SVC or IVC other renalfunctional impairment to suggestinvolvementof a renal syndrome,the left lobe would not becomeuniformly radioactive, vein. In Case 1, the chronicity of the course and the history of if it contains lesions such as metastases. However, disease in the asymmetric involvement of lower extremities indicated a benign left lobeasa possiblebasisfor the nonuniformityappearsto be thrombosis rather than malignant obstruction of the infrarenal exceptional(10,11). In virtually everyinstanceof SVC syndrome, IVC (15). Contrastvenographyin thiscaseshowedapparentbi the liver scanis normal except for visualized collaterals and the lateral iliac venousocclusion. Obstruction of the IVC itself was area of localized activity (1—14).In most instances,there is just not directly demonstrated, but could havebeenpresentsince no a singlewell-definedareaofactivity, which is mostcommonlyseen segmentof the IVC wasvisualized in the dynamic colloid study in the inferior (quadrate) area of the medial segment of the left (Fig. 1). Bilateral occlusionof the commoniliac veins,without an lobe (18). Many other patterns, however, such as that of the obstruction of the IVC, produces almost the same syndrome as that presentCaseI, havebeenobserved.The nonuniformity and varied of an infrarenal IVC obstruction (16). patterns of the abnormal left-lobe uptake in an SVC or IVC syn In Case2, the obstructive level appearedto behigh infrarenal. drome suggesta few possibilities. First, paraumbilically shunted Patencyof the IVC belowthis level,andofthe commoniliac veins, colloid that entersthe left main branch of the portal vein could be was left uncertain. The most common causeof infrarenal and subjectto a streamingeffect within the left main branch. Second, midcaval IVC obstructionsis an ascendingthrombophlebitis from there might be places other than the left main branch where one or both iliofemoral veins (16). Thrombosis can alsOoccur paraumbilically shuntedcolloid could enterthe left-branch system, primarily in the IVC, but may subsequently propagate distally. and theseentry sitescould vary from one patient to another. Thrombotic occlusion of one or both common iliac veins in addition Cavoportal pathways in infrarenal IVC obstruction also include to the IVC would encouragethe developmentof superficial ab visceral routesthrough the inferior and superior mesentericveins dominal collaterals and thus possibly the development of (2!). A liver-scan pattern resulting from shunting through these paraumbilical shunting to the liver aswell (17). mesentericpathways would dependin part on the extent of any A paraumbilical vein, and occasionallya persistent umbilical streaming in the portal vein (vide infra) and on the formation of vein, it is said,join the left main branchofthe portal vein (18,19). the portal vein from its major tributaries, namely,the splenicvein After entering the left main branch, shunted colloid would dis and the mesentericveins(18). Whether the venousbloodfrom the tribute itselfevenly in the left hepaticlobe,ifthere is nostreaming major tributaries completely mixes in the portal vein before of the colloid in the left main branch (18). Activity in the whole reaching the main branches is not clearly known (18). At the 1973 lobe, rather than in a focal area, would result. However,uniform annual meeting of the Radiological Society of North America, trapping in the entire left lobedid not occur in either of thesetwo Henkin and otherspresentedstudiesin a young woman with both cases of IVC syndrome or in any of 26 reported cases of SVC IVC andSVCocclusion.Technetium-99malbuminmicrospheres, FIG.2. SuperfIcialhepatopetalshunting producing increased concentration in quadrate area In Case 2. Tc-99m sulfur ‘4 @. collold (3 mCi)was given Intoleft legvein. Shown are eight consecutivedynamic frames (8 sec/frame, beginning 9th second I j •1•I after Injection)