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Superiority of Balloon Occlusion Arteriography to Reactive Hyperemic Arteriography in Visualization of Distal Lower Limb Vessels
Superiority of Balloon Occlusion Arteriography to Reactive Hyperemic Arteriography in Visualization of Distal Lower Limb Vessels Harold J. Welch, MD, Michael Belkin, MD, Robert Kessler, MD, Victor G. Millan, MD, William C. Mackey, MD, and Thomas F. 0 'Donnell, Jr., MD, Boston, Massachusetts
Balloon occlusion arteriography was performed in 38 lower limbs; reactive hyperemic arteriography was also performed in 16 of these limbs. To assess the safety and utility of this technique the balloon occlusion arteriograms of all 38 patients were reviewed retrospectively by a vascular surgeon and vascular radiologist who were unaware of the patient's identity and ultimate treatment. After the arteriograms were reviewed and the outflow vessels identified, a decision was made regarding operability and optimal recipient vessel for distal bypass. Twenty-two of the 38 patients underwent balloon occlusion arteriography only, and 21/22 (95.5%) of these patients only had studies deemed adequate for surgical planning. Twelve of the 16 (75%) patients underwent both reactive hyperemic arteriography and balloon occlusion arteriography; potential distal outflow vessels not seen on reactive hyperemic arteriograms were observed on balloon occlusion arteriograms. In only 4/16 (25%) patients the balloon occlusion arteriograms did not yield additional information. No complications were associated with this technique. Approximately 8.5 g of iodine per run is used for balloon occlusion arteriography compared with approximately 37 g of iodine per run for reactive hyperemic arteriography. Balloon occlusion arteriography is a safe and accurate adjunctive technique that can be used when identification of lower limb vessels is critical. (Ann Vasc Surg 1993;7:83-87.)
As the limits of lower limb distal bypass have increased, the need for preoperative visualization of acceptable outflow vessels has become more important. Occasionally pathologic arterial a n a t o m y and limited distal perfusion m a y prevent adequate visualization of distal vessels by standard arteriographic techniques. Patients m a y often need a limited contrast load or only require study of a single limb. Some patients m a y be referred to the vascular surgeon for possible surgery after having had
From the Departments of Surgery and Radiology, New England Medical Center Hospital and Tufts University School of Medicine, Boston,Mass. Presentedat the Seventeenth Annual Meeting of the Peripheral Vascular Surgery Society, Chicago,Ill., June 7, 1992. Reprint requests: Michael Belkin, MD, Box 1015, Tufts-New England Medical Center, 750 Washington St., Boston, MA 02111.
suboptimal films from another institution. In these circumstances w e have utilized balloon occlusion arteriography (BOA) to identify the distal vasculature for possible bypass. BOA is performed by briefly arresting inflow to the Ieg with an occluding catheter in the inflow vessel (usually the external iliac artery) while the contrast is injected directly into the outflow tract b e y o n d the occlusive balloon. To investigate the relative benefits of this technique we retrospectively reviewed our experience with BOA in comparison to our standard technique of reactive hyperemic arteriograp h y (RHA). MATERIAL AND METHODS Patients Arteriograms of 38 consecutive patients w h o und e r w e n t BOA from July 1988 to September 1991 83
84
Annalsof VascularSurgery
Welch et al.
were reviewed. Twenty-two patients had BOA only, whereas 16 patients had both BOA and RHA. The 23 males and 15 females ranged in age from 7 to 91 years (mean age 59.1 years). Indications for balloon occlusion arteriography included chronic ischemia (31 limbs), acute ischemia (four limbs), t r a u m a (two limbs), and soft tissue mass (one limb). Of the I6 patients w h o had both BOA and RHA, 11 had severe ischemia (rest pain, tissue loss, and gangrene), four had intermittent claudication, and one had acute ischemia.
Reactive Hyperemic Arteriography A 5.5 F sheath is placed by percutaneous p u n c t u r e of a femoral vessel, t h r o u g h which a 5 F injection catheter is introduced. A blood pressure cuff is inflated on the thigh of the leg(s) to be studied and inflated above systemic pressure for 7 to 10 minutes. The cuff is rapidly deflated, and within 15 seconds the contrast material is injected at a rate of 4 ml/sec. With the use of the step table technique, films are taken at intervals determined by the k n o w n vascular a n a t o m y and the particular area of study in question. For bilateral runoff, approxi-
mately 90 to 100 ml of contrast is injected in the distal aorta per run. For unilateral studies, 45 to 60 ml of contrast is injected.
Balloon Occlusion Arteriography Through a 5.5 F sheath, the 5 F catheter with a 0.75 cc balloon is inserted. If the leg contralateral to the sheath is to be studied, a guidewire is first passed over the aortic bifurcation into the contralateral iliac artery. The balloon catheter is t h e n positioned over the guidewire. Ipsilateral catheters have blunt tips and three side holes proximal to the balloon (Berman angiographic balloon catheter, Arrow International, Inc., Reading, Penn.) (Fig. 1, A). Contralateral catheters are longer and have a single end hole distal to the balloon (balloon wedge pressure catheter, Arrow International, Inc.) (Fig. 1, B). After the balloon is fluoroscopically placed in the inflow artery, occlusion is tested briefly with a small contrast injection. To perform the study the balloon is inflated just prior to contrast injection and deflated immediately after the injection is completed and as film runs are taken. Approximately 30 to 40 ml of contrast is injected
ul~rt6 li~~
Catheter-
A
B
Profunda Sup. Fem. a.
Fig. 1. Balloon occlusion catheters placed percutaneously in the ipsilateral (A) or contralateral (B) external iliac artery.
Vol. 7, No. 1 1993
Superiority of BOA to RHA in visualization of distal lower limb vessels
per run at a rate of 4 ml/sec. If bilateral studies are required, the aortic bifurcation is crossed and the side hole ipsilateral catheter is exchanged over a guidewire for the contralateral end hole catheter. All patients are sedated prior to arteriography. Both the cuff inflation with resulting ischemia used for RHA and the standing column of contrast used in BOA can induce pain. These effects can be alleviated with proper premedication. Film Review Arteriograms were presented with a very brief clinical history to a vascular radiologist and vascular surgeon w h o were u n a w a r e of the patient's identity and ultimate treatment. After they reviewed the films, they rendered their decision regarding operability and the best possible recipient outflow vessel. Of those patients w h o had both RHA and BOA, the RHA films were presented before the BOA films. The reviewers' decision was later compared to the actual treatment performed on each patient. RESULTS
Twenty-two patients had BOA alone. Twenty-one of the 22 patients (95.5%) with BOA alone had studies judged adequate for therapeutic planning. Twelve of those patients had a distal bypass performed to a vessel seen on the BOA, whereas the remaining nine patients were observed, refused r e c o m m e n d e d surgery, or had thrombolytic therapy. Only one study ( 1/22, 4.5 %) was d e e m e d to be inadequate for surgical planning by the reviewing team. Sixteen patients had both BOA and RHA. In 12/16 patients (75%) the BOA revealed a potential recipient distal vessel that was not seen on the RHA. An average of 1.63 outflow vessels per limb were visualized by BOA, whereas RHA identified an average of only 0.42 outflow vessels per limb in
T a b l e I. Comparison of RHA and BOA in 16 patients Potential distal outflow vessels identified Average No. of outflow vessels/limb No. of studies showing no outflow
RHA
BOA
4/16 patients
16/16 patients
0.43
1.63
8l 16
0
85
those same patients. Eight of the 16 RHA studies did not identify a n y outflow vessels. In only 4/16 (2 5 %) the BOA did not yield additional information as compared with the RHA (Table I). If the RHA was the only study available, in the reviewers' opinion, 10 of these 12 patients w o u l d have required an on-table arteriogram during a potential distal bypass. Alternatively, the patients w o u l d have required additional angiographic runs with an increased contrast load to visualize distal vessels. Based on BOA, 10 of those 12 patients underw e n t a successful distal bypass to an outflow vessel identified by BOA, whereas the remaining two patients were treated w i t h o u t surgery. There were no complications related to the use of the balloon occlusion technique. Notably, no arterial disruptions or thrombotic events occurred. DISCUSSION
High-quality arteriograms that provide complete visualization of the distal vessels are essential for optimal surgical planning. Conversely, nonvisualization of patent distal vessels on arteriography m a y result in a negative o u t c o m e for the patient. The patient m a y be advised that reconstructive surgery is not possible and thus be forced to choose b e t w e e n continued pain or a primary amputation. Alternatively, the surgeon m a y opt for blind exploration of the distal vessels and an on-table arteriogram, w h i c h m a y or m a y not identify an outflow vessel and could result in added morbidity. Several m e t h o d s are in current use to identify distal outflow vessels. The c o m m o n l y used step table technique requires accurate timing, b u t differential flow rate b e t w e e n the limbs or angiographer inexperience m a y result in a high contrast load in an attempt to optimize arterial visualization (Figs. 2 and 3). Reactive hyperemia, initiated with either a tourniquet or pharmacologically, is also used to increase flow to distal vessels b u t m a y be painful to the patient. Digital subtraction angiography is c o m m o n l y used and m a y be helpful to identify vessels that overlap bones on plain cut films. This technique has also b e e n s h o w n to provide excellent distal vessel visualization.' It is o u r opinion, however, that digital subtraction angiography is generally inferior to cut films because the images are less sharp and there is less spatial resolution. Magnetic resonance arteriography has b e e n reported to have superior results to standard arteriography, 2 b u t the sophisticated software required to achieve these results are not yet widely available. BOA offers certain advantages w h e n used in the
86
Annals of Vascular Surgery
Welch et al.
A
Fig. 2. A, RHA of tibial vessels. B, BOA of same patient showing anterior tibial artery.
B
A
f
)
Fig. 3. A, RHA of tibial vessels. B, BOA of same patient showing better visualization of tibial vessels.
Fig. 4. Note the excellent visualization of distal vessels with BOA.
p r o p e r circumstances. The m a j o r a d v a n t a g e in o u r e x p e r i e n c e as well as that of o t h e r s 34 is the excellent visualization of distal arteries in those patients w i t h severe p r o x i m a l disease (Fig. 4). Fig. 5 d e m o n s t r a t e s the e x c e l l e n t visualization possible t h r o u g h a plaster cast using BOA. These vessels can be s e e n o n BOA using a d e c r e a s e d contrast load, w h i c h is the s e c o n d m a j o r a d v a n t a g e of BOA. B e c a u s e t h e r e is n o b l o o d to dilute the standing c o l u m n of contrast w i t h BOA, a less c o n c e n t r a t e d m e d i u m (e.g., R e n o g r a f i n - 6 0 ) can be used. With a n a v e r a g e i n j e c t i o n of 30 to 40 ml per limb, the p a t i e n t receives a p p r o x i m a t e l y 8.5 g of iodine per r u n using BOA. This c o m p a r e s to a p p r o x i m a t e l y 37 g of iodine per r u n r e c e i v e d d u r i n g a standard aortic injection w i t h a h i g h e r v o l u m e (50 to 100 ml) of a m o r e c o n c e n t r a t e d m e d i u m (e.g., Ren o g r a f i n - 7 6 ) . This is o b v i o u s l y i m p o r t a n t in patients w i t h d e c r e a s e d renal f u n c t i o n or in those w h o h a v e h a d h y p e r s e n s i t i v i t y reactions to contrast. Patients w h o r e q u i r e r e p e a t studies, such as t h o s e in w h o m s u b o p t i m a l films w e r e t a k e n earlier, b e n e f i t f r o m a d e c r e a s e d contrast load. The third a d v a n t a g e is the simplicity of the t e c h n i q u e . BOA r e q u i r e s o n l y the c o m m e r c i a l l y available ball o o n c a t h e t e r s a n d can be p e r f o r m e d w i t h standard a r t e r i o g r a p h i c e q u i p m e n t . This t e c h n i q u e
Vol. 7, 1993
No. 1
Superiority of BOA to RHA in visualization of distaI lower limb vessels
87
Fig. 5. Visualization of distal vessels through a piaster cast with BOA.
m a y be c o m b i n e d w i t h digital s u b t r a c t i o n arterio g r a p h y as well. T h e r e is m i n i m a l risk i n v o l v e d (i.e., b a l l o o n i n j u r y to the vessel) c o m p a r e d w i t h c o n v e n t i o n a l a r t e r i o g r a p h y a n d t h e cost is c o m petitive. Several p o t e n t i a l d i s a d v a n t a g e s of B O A in c o m parison to RHA exist. The cost of t h e b a l l o o n catheter a n d i n t r o d u c e r s h e a t h is u s u a l l y offset b y t h e f e w e r r u n s p e r f o r m e d a n d films t a k e n . The u n d i luted contrast m a y cause m o r e p a i n o n injection in s o m e patients, a l t h o u g h w e h a v e n o t f o u n d this to be a p r o b l e m . Finally; b a l l o o n i n j u r y to t h e vessel, while theoretically possible, has n o t b e e n o u r experience. O u r c u r r e n t indications for B O A i n c l u d e (1) unilateral l o w e r e x t r e m i t y studies, (2) the n e e d to identify p a r a - or i n f r a m a l l e o l a r vessels n o t visualized o n the initial s t a n d a r d r u n o f f film, a n d (3) patients w i t h p o o r renal f u n c t i o n w h o n e e d arteriography. A l t h o u g h o u r e x p e r i e n c e is limited, w e
h a v e f o u n d it a n excellent t e c h n i q u e in children. We h a v e f o u n d B O A to be a safe a n d h i g h l y accurate a d j u n c t i v e t e c h n i q u e to visualize distal l o w e r limb vessels a n d t h u s o p t i m i z e surgical p l a n n i n g in t h o s e p a t i e n t s w i t h leg ischemia. REFERENCES 1, Hol PK, Heldas J, Skiennald A. Demonstration of pedal arterial arcades in occlusivearteriosclerotic disease: Conventional and digital subtraction angiography compared. Acta Radiol 1989;30:61-63. 2. Carpenter JP, Owen RS, Baum RA, et al. Magnetic resonance angiography: A new gold standard. Presented at the Sixth Annual Meeting of the Eastern Vascular Society. New York: May 1, 1992. 3. Cardella JF, Smith TP, Darcy MD, et al. Balloon occlusion femoral angiography prior to in situ saphenous vein bypass. CardiovascIntervent Radiol 1987;10:181- 187. 4. Santilli SM, Payne WD, Hunter DW, et al. Preoperative comparison of standard angiography with balloon occlusion angiography of the lower extremity {abst.], J Invest Surg 1991;4:368.
Balloon occlusion arteriography was performed in 38 lower limbs; reactive hyperemic arteriography was also performed in 16 of these limbs. To assess the safety and utility of this technique the balloon occlusion arteriograms of all 38 patients were reviewed retrospectively by a vascular surgeon and vascular radiologist who were unaware of the patient's identity and ultimate treatment. After the arteriograms were reviewed and the outflow vessels identified, a decision was made regarding operability and optimal recipient vessel for distal bypass. Twenty-two of the 38 patients underwent balloon occlusion arteriography only, and 21/22 (95.5%) of these patients only had studies deemed adequate for surgical planning. Twelve of the 16 (75%) patients underwent both reactive hyperemic arteriography and balloon occlusion arteriography; potential distal outflow vessels not seen on reactive hyperemic arteriograms were observed on balloon occlusion arteriograms. In only 4/16 (25%) patients the balloon occlusion arteriograms did not yield additional information. No complications were associated with this technique. Approximately 8.5 g of iodine per run is used for balloon occlusion arteriography compared with approximately 37 g of iodine per run for reactive hyperemic arteriography. Balloon occlusion arteriography is a safe and accurate adjunctive technique that can be used when identification of lower limb vessels is critical. (Ann Vasc Surg 1993;7:83-87.)
As the limits of lower limb distal bypass have increased, the need for preoperative visualization of acceptable outflow vessels has become more important. Occasionally pathologic arterial a n a t o m y and limited distal perfusion m a y prevent adequate visualization of distal vessels by standard arteriographic techniques. Patients m a y often need a limited contrast load or only require study of a single limb. Some patients m a y be referred to the vascular surgeon for possible surgery after having had
From the Departments of Surgery and Radiology, New England Medical Center Hospital and Tufts University School of Medicine, Boston,Mass. Presentedat the Seventeenth Annual Meeting of the Peripheral Vascular Surgery Society, Chicago,Ill., June 7, 1992. Reprint requests: Michael Belkin, MD, Box 1015, Tufts-New England Medical Center, 750 Washington St., Boston, MA 02111.
suboptimal films from another institution. In these circumstances w e have utilized balloon occlusion arteriography (BOA) to identify the distal vasculature for possible bypass. BOA is performed by briefly arresting inflow to the Ieg with an occluding catheter in the inflow vessel (usually the external iliac artery) while the contrast is injected directly into the outflow tract b e y o n d the occlusive balloon. To investigate the relative benefits of this technique we retrospectively reviewed our experience with BOA in comparison to our standard technique of reactive hyperemic arteriograp h y (RHA). MATERIAL AND METHODS Patients Arteriograms of 38 consecutive patients w h o und e r w e n t BOA from July 1988 to September 1991 83
84
Annalsof VascularSurgery
Welch et al.
were reviewed. Twenty-two patients had BOA only, whereas 16 patients had both BOA and RHA. The 23 males and 15 females ranged in age from 7 to 91 years (mean age 59.1 years). Indications for balloon occlusion arteriography included chronic ischemia (31 limbs), acute ischemia (four limbs), t r a u m a (two limbs), and soft tissue mass (one limb). Of the I6 patients w h o had both BOA and RHA, 11 had severe ischemia (rest pain, tissue loss, and gangrene), four had intermittent claudication, and one had acute ischemia.
Reactive Hyperemic Arteriography A 5.5 F sheath is placed by percutaneous p u n c t u r e of a femoral vessel, t h r o u g h which a 5 F injection catheter is introduced. A blood pressure cuff is inflated on the thigh of the leg(s) to be studied and inflated above systemic pressure for 7 to 10 minutes. The cuff is rapidly deflated, and within 15 seconds the contrast material is injected at a rate of 4 ml/sec. With the use of the step table technique, films are taken at intervals determined by the k n o w n vascular a n a t o m y and the particular area of study in question. For bilateral runoff, approxi-
mately 90 to 100 ml of contrast is injected in the distal aorta per run. For unilateral studies, 45 to 60 ml of contrast is injected.
Balloon Occlusion Arteriography Through a 5.5 F sheath, the 5 F catheter with a 0.75 cc balloon is inserted. If the leg contralateral to the sheath is to be studied, a guidewire is first passed over the aortic bifurcation into the contralateral iliac artery. The balloon catheter is t h e n positioned over the guidewire. Ipsilateral catheters have blunt tips and three side holes proximal to the balloon (Berman angiographic balloon catheter, Arrow International, Inc., Reading, Penn.) (Fig. 1, A). Contralateral catheters are longer and have a single end hole distal to the balloon (balloon wedge pressure catheter, Arrow International, Inc.) (Fig. 1, B). After the balloon is fluoroscopically placed in the inflow artery, occlusion is tested briefly with a small contrast injection. To perform the study the balloon is inflated just prior to contrast injection and deflated immediately after the injection is completed and as film runs are taken. Approximately 30 to 40 ml of contrast is injected
ul~rt6 li~~
Catheter-
A
B
Profunda Sup. Fem. a.
Fig. 1. Balloon occlusion catheters placed percutaneously in the ipsilateral (A) or contralateral (B) external iliac artery.
Vol. 7, No. 1 1993
Superiority of BOA to RHA in visualization of distal lower limb vessels
per run at a rate of 4 ml/sec. If bilateral studies are required, the aortic bifurcation is crossed and the side hole ipsilateral catheter is exchanged over a guidewire for the contralateral end hole catheter. All patients are sedated prior to arteriography. Both the cuff inflation with resulting ischemia used for RHA and the standing column of contrast used in BOA can induce pain. These effects can be alleviated with proper premedication. Film Review Arteriograms were presented with a very brief clinical history to a vascular radiologist and vascular surgeon w h o were u n a w a r e of the patient's identity and ultimate treatment. After they reviewed the films, they rendered their decision regarding operability and the best possible recipient outflow vessel. Of those patients w h o had both RHA and BOA, the RHA films were presented before the BOA films. The reviewers' decision was later compared to the actual treatment performed on each patient. RESULTS
Twenty-two patients had BOA alone. Twenty-one of the 22 patients (95.5%) with BOA alone had studies judged adequate for therapeutic planning. Twelve of those patients had a distal bypass performed to a vessel seen on the BOA, whereas the remaining nine patients were observed, refused r e c o m m e n d e d surgery, or had thrombolytic therapy. Only one study ( 1/22, 4.5 %) was d e e m e d to be inadequate for surgical planning by the reviewing team. Sixteen patients had both BOA and RHA. In 12/16 patients (75%) the BOA revealed a potential recipient distal vessel that was not seen on the RHA. An average of 1.63 outflow vessels per limb were visualized by BOA, whereas RHA identified an average of only 0.42 outflow vessels per limb in
T a b l e I. Comparison of RHA and BOA in 16 patients Potential distal outflow vessels identified Average No. of outflow vessels/limb No. of studies showing no outflow
RHA
BOA
4/16 patients
16/16 patients
0.43
1.63
8l 16
0
85
those same patients. Eight of the 16 RHA studies did not identify a n y outflow vessels. In only 4/16 (2 5 %) the BOA did not yield additional information as compared with the RHA (Table I). If the RHA was the only study available, in the reviewers' opinion, 10 of these 12 patients w o u l d have required an on-table arteriogram during a potential distal bypass. Alternatively, the patients w o u l d have required additional angiographic runs with an increased contrast load to visualize distal vessels. Based on BOA, 10 of those 12 patients underw e n t a successful distal bypass to an outflow vessel identified by BOA, whereas the remaining two patients were treated w i t h o u t surgery. There were no complications related to the use of the balloon occlusion technique. Notably, no arterial disruptions or thrombotic events occurred. DISCUSSION
High-quality arteriograms that provide complete visualization of the distal vessels are essential for optimal surgical planning. Conversely, nonvisualization of patent distal vessels on arteriography m a y result in a negative o u t c o m e for the patient. The patient m a y be advised that reconstructive surgery is not possible and thus be forced to choose b e t w e e n continued pain or a primary amputation. Alternatively, the surgeon m a y opt for blind exploration of the distal vessels and an on-table arteriogram, w h i c h m a y or m a y not identify an outflow vessel and could result in added morbidity. Several m e t h o d s are in current use to identify distal outflow vessels. The c o m m o n l y used step table technique requires accurate timing, b u t differential flow rate b e t w e e n the limbs or angiographer inexperience m a y result in a high contrast load in an attempt to optimize arterial visualization (Figs. 2 and 3). Reactive hyperemia, initiated with either a tourniquet or pharmacologically, is also used to increase flow to distal vessels b u t m a y be painful to the patient. Digital subtraction angiography is c o m m o n l y used and m a y be helpful to identify vessels that overlap bones on plain cut films. This technique has also b e e n s h o w n to provide excellent distal vessel visualization.' It is o u r opinion, however, that digital subtraction angiography is generally inferior to cut films because the images are less sharp and there is less spatial resolution. Magnetic resonance arteriography has b e e n reported to have superior results to standard arteriography, 2 b u t the sophisticated software required to achieve these results are not yet widely available. BOA offers certain advantages w h e n used in the
86
Annals of Vascular Surgery
Welch et al.
A
Fig. 2. A, RHA of tibial vessels. B, BOA of same patient showing anterior tibial artery.
B
A
f
)
Fig. 3. A, RHA of tibial vessels. B, BOA of same patient showing better visualization of tibial vessels.
Fig. 4. Note the excellent visualization of distal vessels with BOA.
p r o p e r circumstances. The m a j o r a d v a n t a g e in o u r e x p e r i e n c e as well as that of o t h e r s 34 is the excellent visualization of distal arteries in those patients w i t h severe p r o x i m a l disease (Fig. 4). Fig. 5 d e m o n s t r a t e s the e x c e l l e n t visualization possible t h r o u g h a plaster cast using BOA. These vessels can be s e e n o n BOA using a d e c r e a s e d contrast load, w h i c h is the s e c o n d m a j o r a d v a n t a g e of BOA. B e c a u s e t h e r e is n o b l o o d to dilute the standing c o l u m n of contrast w i t h BOA, a less c o n c e n t r a t e d m e d i u m (e.g., R e n o g r a f i n - 6 0 ) can be used. With a n a v e r a g e i n j e c t i o n of 30 to 40 ml per limb, the p a t i e n t receives a p p r o x i m a t e l y 8.5 g of iodine per r u n using BOA. This c o m p a r e s to a p p r o x i m a t e l y 37 g of iodine per r u n r e c e i v e d d u r i n g a standard aortic injection w i t h a h i g h e r v o l u m e (50 to 100 ml) of a m o r e c o n c e n t r a t e d m e d i u m (e.g., Ren o g r a f i n - 7 6 ) . This is o b v i o u s l y i m p o r t a n t in patients w i t h d e c r e a s e d renal f u n c t i o n or in those w h o h a v e h a d h y p e r s e n s i t i v i t y reactions to contrast. Patients w h o r e q u i r e r e p e a t studies, such as t h o s e in w h o m s u b o p t i m a l films w e r e t a k e n earlier, b e n e f i t f r o m a d e c r e a s e d contrast load. The third a d v a n t a g e is the simplicity of the t e c h n i q u e . BOA r e q u i r e s o n l y the c o m m e r c i a l l y available ball o o n c a t h e t e r s a n d can be p e r f o r m e d w i t h standard a r t e r i o g r a p h i c e q u i p m e n t . This t e c h n i q u e
Vol. 7, 1993
No. 1
Superiority of BOA to RHA in visualization of distaI lower limb vessels
87
Fig. 5. Visualization of distal vessels through a piaster cast with BOA.
m a y be c o m b i n e d w i t h digital s u b t r a c t i o n arterio g r a p h y as well. T h e r e is m i n i m a l risk i n v o l v e d (i.e., b a l l o o n i n j u r y to the vessel) c o m p a r e d w i t h c o n v e n t i o n a l a r t e r i o g r a p h y a n d t h e cost is c o m petitive. Several p o t e n t i a l d i s a d v a n t a g e s of B O A in c o m parison to RHA exist. The cost of t h e b a l l o o n catheter a n d i n t r o d u c e r s h e a t h is u s u a l l y offset b y t h e f e w e r r u n s p e r f o r m e d a n d films t a k e n . The u n d i luted contrast m a y cause m o r e p a i n o n injection in s o m e patients, a l t h o u g h w e h a v e n o t f o u n d this to be a p r o b l e m . Finally; b a l l o o n i n j u r y to t h e vessel, while theoretically possible, has n o t b e e n o u r experience. O u r c u r r e n t indications for B O A i n c l u d e (1) unilateral l o w e r e x t r e m i t y studies, (2) the n e e d to identify p a r a - or i n f r a m a l l e o l a r vessels n o t visualized o n the initial s t a n d a r d r u n o f f film, a n d (3) patients w i t h p o o r renal f u n c t i o n w h o n e e d arteriography. A l t h o u g h o u r e x p e r i e n c e is limited, w e
h a v e f o u n d it a n excellent t e c h n i q u e in children. We h a v e f o u n d B O A to be a safe a n d h i g h l y accurate a d j u n c t i v e t e c h n i q u e to visualize distal l o w e r limb vessels a n d t h u s o p t i m i z e surgical p l a n n i n g in t h o s e p a t i e n t s w i t h leg ischemia. REFERENCES 1, Hol PK, Heldas J, Skiennald A. Demonstration of pedal arterial arcades in occlusivearteriosclerotic disease: Conventional and digital subtraction angiography compared. Acta Radiol 1989;30:61-63. 2. Carpenter JP, Owen RS, Baum RA, et al. Magnetic resonance angiography: A new gold standard. Presented at the Sixth Annual Meeting of the Eastern Vascular Society. New York: May 1, 1992. 3. Cardella JF, Smith TP, Darcy MD, et al. Balloon occlusion femoral angiography prior to in situ saphenous vein bypass. CardiovascIntervent Radiol 1987;10:181- 187. 4. Santilli SM, Payne WD, Hunter DW, et al. Preoperative comparison of standard angiography with balloon occlusion angiography of the lower extremity {abst.], J Invest Surg 1991;4:368.