Extrahepatic Portal Obstruction

Additional Article

Extrahepatic Portal Obstruction J. NORMAN YOUNG, M.D.* SAMUEL J. FOGELSON, M.D. F.A.C.S. **

AT THE Cook County Hospital, gastrointestinal bleeding is a frequent and serious problem. A considerable number of these. cases fall into the category of "undetermined etiology," and it is a portion of this group upon which we focus our attention. Exploratory laparotomy becomes mandatory in certain cases when laboratory tests fail to aid in making a conclusive diagnosis. The purpose of this paper is to stress the importance at operation of examining closely the entire area of the opened abdomen, searching particularly for lesions involving the extrahepatic portal circulation. This discussion concerns only portal obstructions occurring from without the substance of the liver. A basic classification of extrahepatic portal obstructions is given in Table 1.1 , 2 , 3 Either the block is located within the structure of the vein or veins per se, or involves them from without by virtue of contiguity. Any structure or organ in proximity to the portal vein and its tributaries, anywhere from the hepatic veins to the terminal branches of the portal radicles, may be the underlying cause of the obstruction. Involvement of the splenic vein alone has been known to cause portal obstruction. Numerous accounts of local portal obstructions have appeared in the literature.v " A great majority of these cases are described at autopsy. We are introducing chronic pancreatitis as another cause of local portal

* Senior Resident Surgeon,

Cook County Hospital, Chicago, Illinois.

** Attending Surgeon, Cook County and Wesley Memorial Hospitals, Chicago Illinois. 54-1

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obstruction and believe it to be the first case reported as such. This lesion was encountered at explorative surgery and is an example of the problem which confronts the surgeon at the operating table. CASE REPORT

K.M., a 39 year old white man, first entered Cook County Hospital on May 15, 1953. His chief complaints were weakness and pallor for 6 months, ankle edema and exertional dyspnea for 1 month. Four years prior to admission he had one episode of severe abdominal pain and vomiting which lasted several days. His alcoholic intake had been moderate with practically none for the past year. Physical Examination. The patient was an extremely pale, anxious male. His pulse was 116, respiration 28 per minute, and blood pressure 122/66. The liver edge was palpable at the costal margin and was soft. The spleen was palpable 4 cm. below the left costal margin. The only other finding was nystagmus which had been present since birth. The stool benzidine test was negative on admission. Table 1 ETIOLOGY OF EXTRAHEPATIC PORTAL OBSTRUCTION

Intrinsic Obstructions A. Thrombosis 1. Inflammation 2. Trauma B. Structural 1. Congenital valves 2. Congenital stenosis Extrinsic Obstructions A. Inflammation 1. Cicatrix 2. Trauma B. Tumors

Laboratory Data. HEMOGRAM: Hematocrit 13 per cent, hemoglobin 11 per cent, red blood cells 1.22 million, white blood cells 9850, differential count showed polymorphonuclears 90 per cent, neutrophil bands 2 per cent, eosinophils absent, basophils 1 per cent, lymphocytes 5 per cent, monocytes 2 per cent. Bone marrow studies were "consistent with severe blood loss." URINE: Negative. HEPATOGRAM: Total protein 5.6. gm./100 cc., serum albumin 4.1 gm./100 cc, serum globulin 1.5 gm./100 cc. Cephalin flocculation 3 plus, thymol turbidity 2.6 units, gamma globulin 0.99 gm./100 cc. Icteric index 8 units, and alkaline phosphatase 3.6 Bodansky units. Gastrointestinal study, including gastroscopy and proctoscopy, were negative. One barium meal demonstrated a possible pressure defect on the inferior margin of the first and second portion of the duodenum, but repeat films did not corroborate this. A thorough hematologic series of tests were negative. Blood replacement was given and the patient was discharged after six weeks with a diagnosis of "bleeding from gastrointestinal tract of undetermined origin." Preoperative Course. K.M. was followed in the anemia clinic for 6 months when again his symptoms of weakness and pallor suddenly occurred. He was readmit-

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ted to the hospital where his pulse was 108 per minute, blood pressure 125/60, and hemoglobin was 10 per cent. On this occasion gastric aspiration gave flecks of blood and stool benzidine tests were markedly positive. Occult stool blood was demonstrated for 2 weeks. Repeated study was again negative and the patient was discharged to the clinic. His third admission was six months later to a surgical service. He entered this time with hematemesis and massive melena. His pulse was 120 per minute, blood pressure 120/80 and hematocrit 8 per cent. Whole blood transfusions were given and laparotomy performed 72 hours later. Operation. A right paramedian incision was made revealing huge varices in the omentum, along the left and right gastric veins, the splenic vein, the peripancreatic veins, and the mesenteric veins. The liver was grossly normal with a sharp inferior margin. The spleen was enlarged to approximately 850 grams. The stomach and duodenum were examined closely and found to be normal. However the entire pancreas was enlarged, especially the head which measured approximately 7 cm. in diameter. This pancreatic mass obstructed the portal vein at the site of entry of its radicles. Above this point the portal vein was of normal size and consistency. Varices were quite evident in the stomach and intestine. Gross blood was seen in the large and small bowel. The duodenum was mobilized for exposure, and from the head of the pancreas a wedge biopsy was taken. Paraffin sections revealed chronic pancreatitis. Postoperative Course. Three weeks after discharge the patient was readmitted with another exsanguination which required 17 transfusions, making a total of 63 units or 31,500 cc. of whole blood received during his illness. He was reoperated upon on August 27, 1954, with the intention of constructing a splenorenal shunt. However, this procedure was not technically possible due to peripancreatic inflammatory cicatrix and the extreme varicose nature of the splenic vein. A splenectomy was done, however. The patient has been free of hemorrhage and is asymptomatic at this time. Corrrmerrt

When pancreatitis is discovered at laparotomy for gastrointestinal hemorrhage, care must be exercised to rule out a cause other than bleeding varices. Solovay and Solovay" reported massive bleeding secondary to a pancreatic abscess rupturing into the duodenum, and another case with a pancreatic stone eroding into the duodenum with bleeding. These might have been mistaken for local portal obstructions if varices had been present. When the anatomic relationships are considered, 7, 8 it is difficult to understand why more portal vein obstructions do not occur: especially due to the pancreas per see A number of cases of pancreatic carcinoma and one of a cyst of the tail of the pancreas causing splenic vein obstruction have been reported (Hurwitt"). However, the portal vein is equally as vulnerable. Its tributaries enter within a circumscribed area of 15 to 20 mm. in diameter dorsal and superior to the neck of the pancreas (Fig. 155). Yet obstruction in this location is a rarity in inflammatory pancreatic diseases. The case presented, however, demonstrates this as the site of the local portal obstruction. Cattell and Warren 1 described a similar case in which the veins about the stomach and spleen were

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enormous and no other gastrointestinal lesion was found. Yet hemorrhage had been massive and responded well to splenectomy. DIAGNOSIS

Splenoportography has been carried out recently in some institutions with great success. This has consisted of portal venography at operation and splenic portography percutaneously. Rousselot, Ruzicka and Doehner studied 50 fresh cadavers by means of injecting barium sulfate into the portal system and x-ray pictures were taken. They described the anatomical variations of the portosplenic angle as "tripod," "T," or "Y"; and measured the diameter of the tributaries in millimeters to determine a standard size. The value of this is to give the surgeon an

Fig. 155. Note the proximity (shaded area) of the tributaries as they join to enter the portal vein and their relationship to the pancreas." 4

objective index from which to determine the abnormal size of veins and to indicate an offending obstruction. However the most important finding in portal venography is demonstration of an existing mechanical "local" portal block. This alone dictates which procedure, a portacaval or splenorenal shunt, should be done. If portograms are not available, pressure studies taken from one of the radicles is sufficient to prove that portal hypertension exists. These can be made easily at the operating table. A spinal manometer with a three way stopcock attachment is filled with isotonic saline. A No. 19 gauge needle is inserted into an accessible portal radicle or the portal vein itself. The stopcock is turned to allow the saline to enter the venous circulation and the pressure can be measured directly. A heparinized

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manometer may be used as well. A pressure of 180 mm. is taken as the upper limits of normal. TREATMENT

Once the site of a local portal obstruction has been demonstrated, surgical intervention is directed toward establishing a normal portal tension and correcting any existing bleeding tendencies. There are three procedures of choice: (1) splenectomy; (2) a shunting procedure around the site of the local block; (3) primary removal of the block. A correlation between the visible lesion and the hematologic picture is important. It must be determined whether the bleeding is due to a local portal obstruction with bleeding varices alone, a hypersplenism with bleeding tendencies, or both. Splenectomy

Should a local block of the splenic vein alone be associated with a picture of hypersplenism, splenectomy should suffice for treatment. On the other hand, the local block may be proximal to the splenic vein, in the region of the mesenteric veins, or the region of the portal vein itself, with bleeding varices in addition to hypersplenism. In this case splenectomy with construction of a splenorenal shunt would be the treatment of choice. Splenectomy reduces the portal pressure 35 to 45 per cent but this may be only of temporary value when dealing with varices. Patients may have repeated episodes of gastrointestinal hemorrhage one to two years after splenectomy alone. A Shunting Procedure

A shunting operation is necessary when a mechanical block exists somewhere between the splenomesenteric venous junction and the liver. This must be done at a site distal to the block. Thus, should the local block be due to a mass in the head of the pancreas, a portacaval shunt would be of no value. A splenorenal shunt would be mandatory. On the other hand, a thrombosis or valve in the portal vein in close proximity to the liver would best be suited to a portacaval shunt just distal to the local block. A shunt using the mesenteric or omental vessels may be attempted on occasion if the size and consistency of the veins make the procedure feasible. Shunts of the portal radicles may be technically impossible owing to the extreme friability and tortuosity of the vessels. In addition, such veins are predisposed to early thrombosis. Removal of the Local Block

The last procedure to be mentioned is removal of the local block itself. This may be relatively simple or extremely dangerous depending upon the nature of the block. Should the pancreas be the cause, as in the case

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reported, we feel that pancreatectomy is too formidable a procedure and should be withheld until shunts and splenectomy have been given a trial.

SUMMARY 1. A case of extrahepatic portal obstruction secondary to chronic pancreatitis is reported. 2. A simplified classification of local portal obstruction is presented. 3. A correlation must be made between the hematologic picture and demonstrated pathologic findings for proper treatment. 4. A plan of treatment is set forth for dealing with all types of extrahepatic portal obstructions.

REFERENCES 1. Cattell, R. B. and Warren, K. W.: Surgery of the Pancreas. Philadelphia, W. B. Saunders Co., 1953. 2. Child, Charles III: The Portal Circulation. New England J. Med. 252: 837, 1955. 3. Rousselot, L. M.: Surgical Therapy for Gastrointestinal Hemorrhage in Portal Hypertension. Rev. Gastroenterology 18: 575, 1951. 4. Puestow, C. B.: Surgery of the Biliary Tract, Pancreas, and Spleen. Chicago, The Year Book Publishers, 1953. 5. Rousselot, L. M. and others: Portal Venography via the Portal and Percutaneous Splenic Routes. Surgery 34: 557, 1953. 6. Solovay, J. and Solovay, H. U.: Comparative Study of Cystic Fibrosis of Pancreas and Chronic Calcareous Pancreatitis: Three Case Reports of Calcareous Pancreatitis. Gastroenterology 14: 509, 1950. 7. Douglass, B. E., Baggenstross, A. H. and Hollinshead, W. H.: The Anatomy 0 f the Portal Vein and its Tributaries. Surg., Gynec. & Obst. 91: 562, 1950. 8. Falconer, C. W. A. and Griffiths, E.: The Anatomy of the Blood Vessels of the Panereas, British J. Surge 37: 334, 1950. . 9. Hurwitt, E. S. and others: Gastrointestinal Bleeding Due to Splenic Vein Obstruction. Arch. Surge 68: 7, 1954. 1800 W. Harrison Street Chicago, Illinois