Arteriovenous Malformation of the Cecum: Report of Six Cases* AMARJIT SINGH, M.D., SADASHIV SHENOY, M.D., AMARJIT KAUR, M . D . , SATISH SACHDANANt), M.D., J. E m v i i
ALFORB, M . D .
From the Departments o[ Colorectal Surgery, Angiology and Pathology of The Blzffalo General Hospital, and State University o[ New York, Buffalo, New York
Report
T o PINPOINT t h e d i a g n o s i s i n a case of a p a t i e n t w i t h c h r o n i c i n t e r m i t t e n t gastroi n t e s t i n a l b l e e d i n g is f r e q u e n t l y a r e a l p r o b l e m . C o n v e n t i o n a l studies m a y fail 50 p e r c e n t of t h e t i m e in f i n d i n g the source, especially w h e n b l e e d i n g is c h r o n i c , i n t e r m i t t e n t a n d a s s o c i a t e d w i t h m e l e n a . 14, 17 E x p l o r a t o r y l a p a r o t o m y has b e e n r e p o r t e d to be n e g a t i v e to a n e x t e n t of 70 p e r cent i n similar instances. 13 A h i s t o r y of fruitless gastric a n d i n t e s t i n a l r e s e c t i o n d o n e b l i n d l y in these p a t i e n t s is f a i r l y c o m m o n . 9 , 17 I t is i n the m a n a g e m e n t of this g r o u p of p a t i e n t s w i t h essentially n e g a t i v e c o n v e n t i o n a l i n v e s t i g a t i o n s t h a t a s u s p i c i o n of a r t e r i o v e n o u s m a l f o r m a t i o n of the cecal a r e a s h o u l d be k e p t i n m i n d a n d the h e l p of the a n g i o g r a p h e r s h o u l d be sought. Acc o r d i n g to Alfidi, t 30 to 70 p e r c e n t of such patients will show arteriovenous malformations. W e p r e s e n t o u r e x p e r i e n c e w i t h this cond i t i o n at T h e B u f f a l o G e n e r a l H o s p i t a l a n d a d d six cases to t h e r e p o r t e d l i t e r a t u r e of 80 cases.l-8, 10-12, 15, 16, 18-20
of Six Cases
Patient I: A 65-year-old man was admitted to the hospital on August 14, 1970, with a history of intermittent rectal bleeding associated with severe anemia since 1967. He had had two hospital admissions in the past with full detailed gastrointestinal work-ups reported as negative except for a non-bleeding duodenal ulcer treated medically since 1967. Gastroscopy during the present admission did not reveal any ulcer. On August 25, 1970, superior mesenteric arteriog-raphy was done. This revealed arteriovenous malformation in the cecal area, with a large vein draining this area. On August 26, 1970, right hemicolectomy was performed. The postoperative course was uneventful. The pathology report confirmed the diagnosis. The patient was discharged on September 4, 1970, and has not experienced any recurrence of rectal bleeding. Patient 2: A 69-year-old man was admitted to the hospital on October 13, 1971, with a history of massive rectal bleeding six months prior to admission, treated with nine units of blood. Exploratory laparotomy had been done at that time and a polyp removed from the sigmoid colon. Three weeks after that operation another episode of bleeding had occurred, which led to sigmoidal resection. He was presently admitted because of another episode of bleeding, 'although it was not as severe as before. Physical examination was unremarkable, with hemoglobin 9.4 g/100 ml and a normal coagulation profile. On October 15, superior mesenteric arteriogTaphy revealed an arteriovenous malformation of the cecum with an early draining large vein. On October 19 right hemicolectomy was performed. The postoperative course was uneventful. The pathology report confirmed the presence of multiple dilated vascular channels in all layers of the cecum. The patient has not experienced rectal bleeding since then.
Materials and Methods Visceral a n g i o ~ a p h y was i n t r o d u c e d at T h e B u f f a l o G e n e r a l H o s p i t a l in 1968. Since t h e n we h a v e e n c o u n t e r e d six cases of a r t e r i o v e n o u s m a l f o r m a t i o n of the cecal area. F o l l o w i n g are the s u m m a r i e s of these cases:
Patient B: A 55-year-old woman was admitted to the hospital on May 8, 1973 with a history of anemia since 1958, along with a history of intermittent blood in the stools with repeatedly negative gastrointestinal work-ups at various area hospitals. On May 15, she underwent superior mesenteric arteriography, which revealed an arterio-
* Received for publication May 19, 1976. Address reprint requests to Dr. Singh: Suite 901, 50-High Street, Buffalo, New York 14203. 384 Dis. Col. & Reet. May-June, 1977
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PxG. 1, Superior mesenteric arteriography shows numerous dilated and tortuous arteries in the cecal area.
Fie, 2. Venous phase shows the dilated veins in the cecum joining to form a large draining vein,
3 ~5
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venous m a l f o r m a t i o n in the cecal area with early d r a i n i n g veins. She u n d e r w e n t right hemicolectomy on May 21. T h e pathology report confirmed the diag-nosis. T h e patient did well a n d was discharged on J u n e 1. She h a s not h a d a recurrence of rectal hleeding.
30 revealed a n a b n o r m a l cluster of vessels in the cecum a n d lower right colon, with s u b s e q u e n t extravasation of contrast m e d i u m into the l u m e n (Fig. 3). R i g h t hemicolectomy was carried o u t on December 30. T h e patient was discharged on Janu a r y 6 a n d has h a d no recurrence of bleeding.
P a t i e n t 4: A 78-year-old w o m a n was a d m i t t e d to the hospital on J u l y 17, 1973, with moderate rectal bleeding a n d increased fatigue. She h a d a past history of i n t e r m i t t e n t rectal bleeding since 1971, for which she h a d h a d a sigmoidal resection six m o n t h s previously. Physical e x a m i n a t i o n disclosed a systolic m u r m u r of aortic stenosis, which was t h o u g h t n o t to be significant clinically. H e m o globin on admission was 7.7 g/100 ml. On July 30, superior mesenterie a r t e r i o g r a p h y revealed a large arteriovenous m a l f o r m a t i o n in the cecal area (Figs. 1 a n d 2). R i g h t hemicolectomy was p e r f o r m e d on August 3. T h e pathology report confirmed arteriovenous m a l f o r m a t i o n of the cecum and ileum. T h e patient was discharged on A u g u s t 11 and has not experienced rectal bleeding since.
P a t i e n t 6: A 65-year-old w o m a n was a d m i t t e d to the hospital on September 9, 1975, with a history of i n t e r m i t t e n t black to tarry stools for the preceding ten years. She felt discomfort a n d tenderness in the right lower q u a d r a n t before t h e beginn i n g of each episode. Seven years previously she h a d u n d e r g o n e l a p a r o t o m y a n d b l i n d subtotal gastrectomy for this p r o b l e m at a n o t h e r hospital. Pathologic e x a m i n a t i o n of the s t o m a c h h a d disclosed no abnormality, a n d the pat"_ent c o n t i n u e d to have rectal bleeding. She h a d been treated with hemetinics u n t i l the present m o d e r a t e l y severe episode, w h i c h had m a d e h e r seek a n o t h e r opinion. Superior mesenteric a t e r i o g r a p h y on S e p t e m b e r 19, 1975, revealed an arteriovenous m a l f o r m a t i o n in the cecal area with an early d r a i n i n g vein (Fig. 4). O n September 24 the p a t i e n t u n d e r w e n t right hemicolectomy. T h e postoperative course was u n e v e n t f u l , a n d the p a t i e n t was discharged September 30. She has h a d no recurrence of rectal bleeding.
P a t i e n t 5: A 28-year-old m a n (physician) was admitted to the hospital on December 29, 1974, for a second episode of rectal bleeding. No source of bleeding h a d been f o u n d on a previous admission. Superior mesenteric arteriography on December
FIG. 3. Superior mesenteric a r t e r i o g r a p h y shows extravasation of contrast m e d i u m into the l u m e n of the cecum. A large d r a i n i n g vein is also visible.
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Fie. 4. S u p e r i o r mesenteric a r t e r i o g r a m shows tortuous a r t e r i a l a r c h i t e c t u r e in the m e d i a l wall of the cecum w i t h an early d r a i n i n g vein.
Discussion T h e exact etiology of this condition is obscure. This problem is not associated with hereditary telangiectasia or Rendu-OslerWeber syndrome. T h e r e are many reports relating arteriovenous malformations to aortic stenosis. In one series, t9 aortic stenosis was present in 25 per cent of patients who h a d gastrointestinal bleeding of obscure origin, compared with a 5 per cent incidence in the average population. Baum et al. 4 consider this problem to be the end result of chronic mucosal ischemia due to intermittent increased intraluminal pressure leading to chronic arteriovenous shunting in the submucosa. This was refuted by Baer and Ryan 3 in their detailed study of cecal vasculature. Arteriovenous malformations have been found in the appendeceal stump following appendectomy t~ but, as appendectomy is a common operation and arteriovenous malformation is very rare, the two could not be related.
Clinical Features: These patients are middle-aged to elderly, although one patient in our series was 28 years old. T h e r e is usually a female preponderance. The duration of bleeding is usually very long; a period of 36 years has been reported. 1 Usually there is a history of negative gastrointestinal work-ups, negative laparotomies, and even blind gastric or intestinal resections with no relief. Occasionally a patient may complain of discomfort in the right lower quadrant prior to bleeding. T h e amounts of blood lost vary, usually being small to moderate. Occasionally, massive colonic hemorrhage occurs. Physical examination is usually not contributory except for anemia and guaiac-positive stools. Sigmoidoscopic and barium-enema examinations are always negative. Colonoscopy may occasionally reveal minute ulcerations in the cecal area. Angiographic Features: Selective superior mesenteric arteriography is the investiga-
~38
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Dis. CoL & Rect. May-June, 1977
FIc. 5. Photomicrog-raph of the m u c o u s m e m b r a n e of the cecum, showing a p o r t i o n of a colonic g l a n d (tipper left corner). Mucosal infiltrate with h e m o r r h a g e and a thin-walled superficial blood vessel r u n n i n g horizontally (hematoxylin a n d eosin; X 65, reduced from X 75).
tion of choice in confirming the diagnosis of arteriovenous malformation. Rarely, a calcified phlebolith in the right lower quadrant may be helpful in suggesting the diagnosis. Aortography frequently fails to localize these lesions because of the marked dilution of the contrast medium. Selective arteriography is done via the percutaneous femoral route by the Seldinger technique. Selective superior mesenteric arteriography shows a characteristic appearance consisting of collections of dilated irregular small vessels that fill rapidly during the arterial phase. A diffuse stain may sometimes be seen during the parenchymat phase. T h e hallmark of this lesion is, however, the early" draining veins. If selective arteriography is carried out during active bleeding, extravasation of the contrast medium into the colon may be observed (as in Patient 5). In order to rule out other malformations, selec-
tive celiac and inferior mesenteric arteriography should be done. In the differential diagnosis one has to consider the possibility of carcinoma and o/her malignancies. However, these entities usually show a mass effect on barium studies.' Pathologic Features: Since the majority of vascular malformations in the right colon are not grossly visible, few have been studied morphologically except when there were clinical indications to do so. In a few cases careful examination with either a hand lens or a dissecting microscope may disclose superficial hemorrhages a n d / o r erosions. T h e most satisfactory method for demonstrating these lesions is to inject the vascular tree with dye, gelatin and contrast material, individually or in combination. Microscopically, the mucosa is usually intact, and dilated thin-walled blood vessels are identified in the submucosa .(Fig. 5).
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Areas of hemorrhage may be seen in the mucosa, but are more often found in the submucosa. Elastic tissue stains demop.strate either eccentric loss of the elastic lamellae and muscular components or total absence of one or both. This presumably results in vessel wall fragility and the tendency to bleed. We were unable to demonstrate arteriovenous anastomosis in any of our cases. Treatment: Once the diagnosis is made preoperatively, the logical treatment is right hemicolectomy with ileotransverse colostomy. These lesions usually cannot be visualized at operation. Occasionally a group of dilated veins may be seen. In our series no patient has had a recur: rence of rectal bleeding since operation. In Baum's s series two of 12 patients had recurrent bleeding. These were further investigated and found to have similar lesions in the colon and rectum. Summary Patients who have chronic lower gastrointestinal bleeding with negative conventional work-ups should undergo superior mesenteric arteriography to look for arteriovenous malformations. Once the diagnosis is made, treatment is immediate conventional right hemicolectomy. Six patients with arteriovenons malformations described in this report have had no recurrence of rectal bleeding in one to five years. Acknowledgment The authors thank Mr. Bruce F, Lucca for photographing the x-rays.
References f I. Alfidi RU: Angiography in identifying the source of imestinal bleeding (symposium). Dis Colon Rectum 17: 442, 1974 2. Arvanitakis C: Localization of bleeding vascular lesions in the gastrointestinal tract. Wis Med J 72: 139, 1973 3. Baer JW, Ryan S: Analysis of cecal vasculature in the search for vascular malformations. Am J Roentgenol Radium Ther Nucl Med 126: 394, 1976
339
4. Baum S, Athanasoutis CA, Waltman AC: Angiographic diagnosis and control of largebowel bleeding (symposium) . Dis Colon Rectum 17: 447, 1974 5. Baum S, Athanasoulis CA, Wahman AC, et al: Angiodysplasia of the right colon as a cause of chronic gastrointestinal bleeding (unpublished data) 6. Boijsen E, Hartel M: Kontrastmittelpassagezeiten im Versogungsgebeit der Arteria mesenterica superior. Fortschr Rontgenstr Nnklearmed 118: 491, 1973 7. Casarella WJ, Galloway SJ, Taxin RN, et a h "Lower" gastrointestinal tract hemorrhage: New concepts based on arteriography. Am J Roentgenol Radium Ther Nucl Med 121: 357, 1974 8. Cooperman AM, Kelly KA, Bernatz PE, et a h Arteriovenous malformation of the intestine. Arch Surg 104: 284, 1972 9. Farries HW: Uber die Htimangiome des Damles unter Anfiihrung eines eigenen Falles. Bruns Beitr Klin Chir 192: 224, 1956 10. Foster JH, Morgan CV, Therlkell JB, et a h Vascular malfol-mation of the appendiceal stump: A rare cause of massive hemorrhage. JAMA 215: 636, 1971 11. Galloway SJ, Casarella }vJ, Shimkin PM: Vascular malfo~-mations of the right colon as a cause of bleeding in patients with aortic stenosis. Radiology 113: 11, 1974 12. Margulis AR, Heinbecker P, Bernard HR: Operative mesenteric ateriog-raphy in the search for the site of bleeding in unexplained gastrointestinal hemorrhage: A preliminary report. Surgery 48: 534, 1960 13. Retzlaff JA, Hagedorn AB, Bartholomew LG: Abdominal exploration for gastrointestinal bleeding of obscure origin. JAMA 177: 104, 1961 14. Rives JD, Emmett RO: Massive melena: Survey of 129 cases seen at Charity Hospital from March 1950, to December 1952. J La Med Soc 105: 273, 1953 15. R6sch J, Gray RK, Grolhnan JH Jr, et a h Selective arterial drug infusions in the treatment of acute gastrointestinal bleeding: A preliminary report. Gastroenterology 59: 341, 1970 16. Shawalter B, Johnson DO, Wise RE: Arteriovenous malformation of the intestine diagnosed by angiography. Lahey Clin Found Bull 19: 22, 1970 17. Shepherd JA: Angiomatous conditions of the gastro-intestinal tract. Br J Surg 40: 409, 1953 18. Van der Ghinst M, Dernier P, Ponikelsky V: Diagnostic prdop6ratoir d'un angiome caecal hdmorragique par angiographie selective. Indications de cet examen. Chirurgie 97: 493, 1971 19. Wholey MH, Bron KM, Haller JD: Selective angiography of the colon. Surg Clin North Am 45:1283 (Oct) 1965 20. Williams RC Jr: Aortic stenosis and unexplained gastrointestinal bleeding. Arch Intern Med 108: 859, 1961
ALFORB, M . D .
From the Departments o[ Colorectal Surgery, Angiology and Pathology of The Blzffalo General Hospital, and State University o[ New York, Buffalo, New York
Report
T o PINPOINT t h e d i a g n o s i s i n a case of a p a t i e n t w i t h c h r o n i c i n t e r m i t t e n t gastroi n t e s t i n a l b l e e d i n g is f r e q u e n t l y a r e a l p r o b l e m . C o n v e n t i o n a l studies m a y fail 50 p e r c e n t of t h e t i m e in f i n d i n g the source, especially w h e n b l e e d i n g is c h r o n i c , i n t e r m i t t e n t a n d a s s o c i a t e d w i t h m e l e n a . 14, 17 E x p l o r a t o r y l a p a r o t o m y has b e e n r e p o r t e d to be n e g a t i v e to a n e x t e n t of 70 p e r cent i n similar instances. 13 A h i s t o r y of fruitless gastric a n d i n t e s t i n a l r e s e c t i o n d o n e b l i n d l y in these p a t i e n t s is f a i r l y c o m m o n . 9 , 17 I t is i n the m a n a g e m e n t of this g r o u p of p a t i e n t s w i t h essentially n e g a t i v e c o n v e n t i o n a l i n v e s t i g a t i o n s t h a t a s u s p i c i o n of a r t e r i o v e n o u s m a l f o r m a t i o n of the cecal a r e a s h o u l d be k e p t i n m i n d a n d the h e l p of the a n g i o g r a p h e r s h o u l d be sought. Acc o r d i n g to Alfidi, t 30 to 70 p e r c e n t of such patients will show arteriovenous malformations. W e p r e s e n t o u r e x p e r i e n c e w i t h this cond i t i o n at T h e B u f f a l o G e n e r a l H o s p i t a l a n d a d d six cases to t h e r e p o r t e d l i t e r a t u r e of 80 cases.l-8, 10-12, 15, 16, 18-20
of Six Cases
Patient I: A 65-year-old man was admitted to the hospital on August 14, 1970, with a history of intermittent rectal bleeding associated with severe anemia since 1967. He had had two hospital admissions in the past with full detailed gastrointestinal work-ups reported as negative except for a non-bleeding duodenal ulcer treated medically since 1967. Gastroscopy during the present admission did not reveal any ulcer. On August 25, 1970, superior mesenteric arteriog-raphy was done. This revealed arteriovenous malformation in the cecal area, with a large vein draining this area. On August 26, 1970, right hemicolectomy was performed. The postoperative course was uneventful. The pathology report confirmed the diagnosis. The patient was discharged on September 4, 1970, and has not experienced any recurrence of rectal bleeding. Patient 2: A 69-year-old man was admitted to the hospital on October 13, 1971, with a history of massive rectal bleeding six months prior to admission, treated with nine units of blood. Exploratory laparotomy had been done at that time and a polyp removed from the sigmoid colon. Three weeks after that operation another episode of bleeding had occurred, which led to sigmoidal resection. He was presently admitted because of another episode of bleeding, 'although it was not as severe as before. Physical examination was unremarkable, with hemoglobin 9.4 g/100 ml and a normal coagulation profile. On October 15, superior mesenteric arteriogTaphy revealed an arteriovenous malformation of the cecum with an early draining large vein. On October 19 right hemicolectomy was performed. The postoperative course was uneventful. The pathology report confirmed the presence of multiple dilated vascular channels in all layers of the cecum. The patient has not experienced rectal bleeding since then.
Materials and Methods Visceral a n g i o ~ a p h y was i n t r o d u c e d at T h e B u f f a l o G e n e r a l H o s p i t a l in 1968. Since t h e n we h a v e e n c o u n t e r e d six cases of a r t e r i o v e n o u s m a l f o r m a t i o n of the cecal area. F o l l o w i n g are the s u m m a r i e s of these cases:
Patient B: A 55-year-old woman was admitted to the hospital on May 8, 1973 with a history of anemia since 1958, along with a history of intermittent blood in the stools with repeatedly negative gastrointestinal work-ups at various area hospitals. On May 15, she underwent superior mesenteric arteriography, which revealed an arterio-
* Received for publication May 19, 1976. Address reprint requests to Dr. Singh: Suite 901, 50-High Street, Buffalo, New York 14203. 384 Dis. Col. & Reet. May-June, 1977
Volume 20 Number 4
Volume 20 Number 4
A R T E R I O V E N O U S M A L F O R M A T I O N OF CECUM
PxG. 1, Superior mesenteric arteriography shows numerous dilated and tortuous arteries in the cecal area.
Fie, 2. Venous phase shows the dilated veins in the cecum joining to form a large draining vein,
3 ~5
336
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venous m a l f o r m a t i o n in the cecal area with early d r a i n i n g veins. She u n d e r w e n t right hemicolectomy on May 21. T h e pathology report confirmed the diag-nosis. T h e patient did well a n d was discharged on J u n e 1. She h a s not h a d a recurrence of rectal hleeding.
30 revealed a n a b n o r m a l cluster of vessels in the cecum a n d lower right colon, with s u b s e q u e n t extravasation of contrast m e d i u m into the l u m e n (Fig. 3). R i g h t hemicolectomy was carried o u t on December 30. T h e patient was discharged on Janu a r y 6 a n d has h a d no recurrence of bleeding.
P a t i e n t 4: A 78-year-old w o m a n was a d m i t t e d to the hospital on J u l y 17, 1973, with moderate rectal bleeding a n d increased fatigue. She h a d a past history of i n t e r m i t t e n t rectal bleeding since 1971, for which she h a d h a d a sigmoidal resection six m o n t h s previously. Physical e x a m i n a t i o n disclosed a systolic m u r m u r of aortic stenosis, which was t h o u g h t n o t to be significant clinically. H e m o globin on admission was 7.7 g/100 ml. On July 30, superior mesenterie a r t e r i o g r a p h y revealed a large arteriovenous m a l f o r m a t i o n in the cecal area (Figs. 1 a n d 2). R i g h t hemicolectomy was p e r f o r m e d on August 3. T h e pathology report confirmed arteriovenous m a l f o r m a t i o n of the cecum and ileum. T h e patient was discharged on A u g u s t 11 and has not experienced rectal bleeding since.
P a t i e n t 6: A 65-year-old w o m a n was a d m i t t e d to the hospital on September 9, 1975, with a history of i n t e r m i t t e n t black to tarry stools for the preceding ten years. She felt discomfort a n d tenderness in the right lower q u a d r a n t before t h e beginn i n g of each episode. Seven years previously she h a d u n d e r g o n e l a p a r o t o m y a n d b l i n d subtotal gastrectomy for this p r o b l e m at a n o t h e r hospital. Pathologic e x a m i n a t i o n of the s t o m a c h h a d disclosed no abnormality, a n d the pat"_ent c o n t i n u e d to have rectal bleeding. She h a d been treated with hemetinics u n t i l the present m o d e r a t e l y severe episode, w h i c h had m a d e h e r seek a n o t h e r opinion. Superior mesenteric a t e r i o g r a p h y on S e p t e m b e r 19, 1975, revealed an arteriovenous m a l f o r m a t i o n in the cecal area with an early d r a i n i n g vein (Fig. 4). O n September 24 the p a t i e n t u n d e r w e n t right hemicolectomy. T h e postoperative course was u n e v e n t f u l , a n d the p a t i e n t was discharged September 30. She has h a d no recurrence of rectal bleeding.
P a t i e n t 5: A 28-year-old m a n (physician) was admitted to the hospital on December 29, 1974, for a second episode of rectal bleeding. No source of bleeding h a d been f o u n d on a previous admission. Superior mesenteric arteriography on December
FIG. 3. Superior mesenteric a r t e r i o g r a p h y shows extravasation of contrast m e d i u m into the l u m e n of the cecum. A large d r a i n i n g vein is also visible.
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Fie. 4. S u p e r i o r mesenteric a r t e r i o g r a m shows tortuous a r t e r i a l a r c h i t e c t u r e in the m e d i a l wall of the cecum w i t h an early d r a i n i n g vein.
Discussion T h e exact etiology of this condition is obscure. This problem is not associated with hereditary telangiectasia or Rendu-OslerWeber syndrome. T h e r e are many reports relating arteriovenous malformations to aortic stenosis. In one series, t9 aortic stenosis was present in 25 per cent of patients who h a d gastrointestinal bleeding of obscure origin, compared with a 5 per cent incidence in the average population. Baum et al. 4 consider this problem to be the end result of chronic mucosal ischemia due to intermittent increased intraluminal pressure leading to chronic arteriovenous shunting in the submucosa. This was refuted by Baer and Ryan 3 in their detailed study of cecal vasculature. Arteriovenous malformations have been found in the appendeceal stump following appendectomy t~ but, as appendectomy is a common operation and arteriovenous malformation is very rare, the two could not be related.
Clinical Features: These patients are middle-aged to elderly, although one patient in our series was 28 years old. T h e r e is usually a female preponderance. The duration of bleeding is usually very long; a period of 36 years has been reported. 1 Usually there is a history of negative gastrointestinal work-ups, negative laparotomies, and even blind gastric or intestinal resections with no relief. Occasionally a patient may complain of discomfort in the right lower quadrant prior to bleeding. T h e amounts of blood lost vary, usually being small to moderate. Occasionally, massive colonic hemorrhage occurs. Physical examination is usually not contributory except for anemia and guaiac-positive stools. Sigmoidoscopic and barium-enema examinations are always negative. Colonoscopy may occasionally reveal minute ulcerations in the cecal area. Angiographic Features: Selective superior mesenteric arteriography is the investiga-
~38
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Dis. CoL & Rect. May-June, 1977
FIc. 5. Photomicrog-raph of the m u c o u s m e m b r a n e of the cecum, showing a p o r t i o n of a colonic g l a n d (tipper left corner). Mucosal infiltrate with h e m o r r h a g e and a thin-walled superficial blood vessel r u n n i n g horizontally (hematoxylin a n d eosin; X 65, reduced from X 75).
tion of choice in confirming the diagnosis of arteriovenous malformation. Rarely, a calcified phlebolith in the right lower quadrant may be helpful in suggesting the diagnosis. Aortography frequently fails to localize these lesions because of the marked dilution of the contrast medium. Selective arteriography is done via the percutaneous femoral route by the Seldinger technique. Selective superior mesenteric arteriography shows a characteristic appearance consisting of collections of dilated irregular small vessels that fill rapidly during the arterial phase. A diffuse stain may sometimes be seen during the parenchymat phase. T h e hallmark of this lesion is, however, the early" draining veins. If selective arteriography is carried out during active bleeding, extravasation of the contrast medium into the colon may be observed (as in Patient 5). In order to rule out other malformations, selec-
tive celiac and inferior mesenteric arteriography should be done. In the differential diagnosis one has to consider the possibility of carcinoma and o/her malignancies. However, these entities usually show a mass effect on barium studies.' Pathologic Features: Since the majority of vascular malformations in the right colon are not grossly visible, few have been studied morphologically except when there were clinical indications to do so. In a few cases careful examination with either a hand lens or a dissecting microscope may disclose superficial hemorrhages a n d / o r erosions. T h e most satisfactory method for demonstrating these lesions is to inject the vascular tree with dye, gelatin and contrast material, individually or in combination. Microscopically, the mucosa is usually intact, and dilated thin-walled blood vessels are identified in the submucosa .(Fig. 5).
Volume 20 Number 4
ARTERIOVENOUS MALFORMATION OF CECUM
Areas of hemorrhage may be seen in the mucosa, but are more often found in the submucosa. Elastic tissue stains demop.strate either eccentric loss of the elastic lamellae and muscular components or total absence of one or both. This presumably results in vessel wall fragility and the tendency to bleed. We were unable to demonstrate arteriovenous anastomosis in any of our cases. Treatment: Once the diagnosis is made preoperatively, the logical treatment is right hemicolectomy with ileotransverse colostomy. These lesions usually cannot be visualized at operation. Occasionally a group of dilated veins may be seen. In our series no patient has had a recur: rence of rectal bleeding since operation. In Baum's s series two of 12 patients had recurrent bleeding. These were further investigated and found to have similar lesions in the colon and rectum. Summary Patients who have chronic lower gastrointestinal bleeding with negative conventional work-ups should undergo superior mesenteric arteriography to look for arteriovenous malformations. Once the diagnosis is made, treatment is immediate conventional right hemicolectomy. Six patients with arteriovenons malformations described in this report have had no recurrence of rectal bleeding in one to five years. Acknowledgment The authors thank Mr. Bruce F, Lucca for photographing the x-rays.
References f I. Alfidi RU: Angiography in identifying the source of imestinal bleeding (symposium). Dis Colon Rectum 17: 442, 1974 2. Arvanitakis C: Localization of bleeding vascular lesions in the gastrointestinal tract. Wis Med J 72: 139, 1973 3. Baer JW, Ryan S: Analysis of cecal vasculature in the search for vascular malformations. Am J Roentgenol Radium Ther Nucl Med 126: 394, 1976
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4. Baum S, Athanasoutis CA, Waltman AC: Angiographic diagnosis and control of largebowel bleeding (symposium) . Dis Colon Rectum 17: 447, 1974 5. Baum S, Athanasoulis CA, Wahman AC, et al: Angiodysplasia of the right colon as a cause of chronic gastrointestinal bleeding (unpublished data) 6. Boijsen E, Hartel M: Kontrastmittelpassagezeiten im Versogungsgebeit der Arteria mesenterica superior. Fortschr Rontgenstr Nnklearmed 118: 491, 1973 7. Casarella WJ, Galloway SJ, Taxin RN, et a h "Lower" gastrointestinal tract hemorrhage: New concepts based on arteriography. Am J Roentgenol Radium Ther Nucl Med 121: 357, 1974 8. Cooperman AM, Kelly KA, Bernatz PE, et a h Arteriovenous malformation of the intestine. Arch Surg 104: 284, 1972 9. Farries HW: Uber die Htimangiome des Damles unter Anfiihrung eines eigenen Falles. Bruns Beitr Klin Chir 192: 224, 1956 10. Foster JH, Morgan CV, Therlkell JB, et a h Vascular malfol-mation of the appendiceal stump: A rare cause of massive hemorrhage. JAMA 215: 636, 1971 11. Galloway SJ, Casarella }vJ, Shimkin PM: Vascular malfo~-mations of the right colon as a cause of bleeding in patients with aortic stenosis. Radiology 113: 11, 1974 12. Margulis AR, Heinbecker P, Bernard HR: Operative mesenteric ateriog-raphy in the search for the site of bleeding in unexplained gastrointestinal hemorrhage: A preliminary report. Surgery 48: 534, 1960 13. Retzlaff JA, Hagedorn AB, Bartholomew LG: Abdominal exploration for gastrointestinal bleeding of obscure origin. JAMA 177: 104, 1961 14. Rives JD, Emmett RO: Massive melena: Survey of 129 cases seen at Charity Hospital from March 1950, to December 1952. J La Med Soc 105: 273, 1953 15. R6sch J, Gray RK, Grolhnan JH Jr, et a h Selective arterial drug infusions in the treatment of acute gastrointestinal bleeding: A preliminary report. Gastroenterology 59: 341, 1970 16. Shawalter B, Johnson DO, Wise RE: Arteriovenous malformation of the intestine diagnosed by angiography. Lahey Clin Found Bull 19: 22, 1970 17. Shepherd JA: Angiomatous conditions of the gastro-intestinal tract. Br J Surg 40: 409, 1953 18. Van der Ghinst M, Dernier P, Ponikelsky V: Diagnostic prdop6ratoir d'un angiome caecal hdmorragique par angiographie selective. Indications de cet examen. Chirurgie 97: 493, 1971 19. Wholey MH, Bron KM, Haller JD: Selective angiography of the colon. Surg Clin North Am 45:1283 (Oct) 1965 20. Williams RC Jr: Aortic stenosis and unexplained gastrointestinal bleeding. Arch Intern Med 108: 859, 1961
