Venous Angiography and the Surgical Management of Subcutaneous Hemodialysis Fistulas CHARLES B. ANDERSON, M.D., LOUIS A. GILULA, M.D., HERSCHEL R. HARTER, M.D., EDWARD E. ETHEREDGE, M.D.
Venous angiography of subcutaneous arteriovenous (A-V) hemodialysis fistulas involves venous injection of radiographic contrast material which spreads throughout the venous system and into the arteries via the A-V anastomosis when blood flow to the extremity is temporarily occluded. Direct arterial cannulation is avoided. Subsequent restoration of blood flow with rapid sequential roentgenograms differentiates arteries from veins and identifies direction of fistula blood flow. A 44 month experience with 125 consecutive studies in 82 patients was performed with a 0.8% complication rate. Indications for fistulography included insufficient blood flow during dialysis (67%), cardiac failure (10%), aneurysms (6%), sepsis of undetermined site (6%) and other (11%). Roentgenographic findings identified vascular stenoses or occlusions (45%), malpositioned dialysis needles (11%), aneurysms (9%), unsuitable veins for dialysis (6%), absence of septic origin (5%), abnormal flow rates or patterns (5%), technically unsuitable studies (2%) and normal or baseline studies (17%). Information useful in planning clinical management of the patient was obtained in 88% of studies and fistula operations were performed in 65 patients (52%). Venous fistulography can be an effective and safe method of evaluating and planning correction of A-V dialysis fistula complications. T HE
SUBCUTANEOUS
ARTERIOVENOUS
From the Departments of Surgery, Radiology (Mailinckrodt Institute of Radiology), and Medicine (Chromalloy American Kidney Center); Washington University School of Medicine, St. Louis, Missouri
proved to be a safe, reliable and effective method of radiographically demonstrating both the arterial and venous components of the AVF by injecting the venous limb, thus avoiding arterial catheterization. It is now an integral part of our investigation of the malfunctioning AVF to determine if an anatomical complication exists, whether it can be repaired, and if so, which operative approach would best serve to correct the problem. This report reviews an experience with 125 consecutive examinations, analyzes the usefulness of the technique in patient management and presents representative cases to emphasize important findings. Technique Fluid injected into a passive system of tubes will spread evenly throughout the entire system; thus, when the arteriovenous pressure differential has been eliminated, a venous injection near the orifice of a fistula will allow contrast material to pass from the vein into the artery. With the patient supine, a blood pressure cuff is placed around the upper arm. Preliminary radiographs are obtained in both anteroposterior and lateral projections. The x-ray tube is centered to include the fistula, which is identified by a thrill in the area of the cutaneous scar, and major feeding and draining vessels. The skin is prepared antiseptically, and a 19 gauge scalp-vein needle is inserted into the proximal or distal venous limb of the anastomosis, so that the tip lies one centimeter away from and points toward the fistula. The needle is attached to a connecting tube and flushed with heparinized saline to prevent clotting. A 20
FISTULA
(AVF) is the preferred method for maintaining vascular access for chronic hemodialysis. Since first described by Brescia et al.' in 1966, the technique has had many modifications including the use of autogenous veins, human umbilical veins, synthetic material and processed bovine carotid arteries. Numerous articles have analyzed a wide variety of AVF and their functional usefulness for repeated cannulation. With the increased use of AVF, the complications have become more common. Vascular surgeons are being required to evaluate and revise these malfunctioning AVF to permit immediate use of mature veins and to conserve vessels for later use. Venous fistulography,4 a diagnostic tool developed at our institution, has been helpful in managing AVF complications. Since 1973, this method has Submitted for publication: June 13, 1977.
0003-4932-78-0200-0194-0115 © J. B. Lippincott Company
194
Vol. 187 . No. 2
ANGIOGRAPHY AND FISTULA MANAGEMENT
195
DAJ :..
.-
FIG. lb. Release of the prescuff clears contrast material first from the proximal radial artery, thus distinguishing it from the veins (V) which increasingly fills with contrast material. sure
FIG. la. With the arm blood pressure cuff inflated above arterial systolic pressure, contrast material injected into the cephalic vein spreads into communicating veins as well as the radial artery proximal (PAL) and distal (DAL) to the fistulous communication (arrow). A normal end cephalic vein (CV) to side of radial artery anastomosis is demonstrated. A = radial artery, V = cephalic vein.
ml syringe filled with 20% methyglucamine diatrizoate (60% methyglucamine diatrizoate diluted with sterile saline to 20%) is attached to the connecting tube. A cuff pressure of approximately 250 mmHg is applied to occlude all blood flow in the arm. When the cuff is properly inflated, the fistula thrill and arterial pulse disappear. A 20 ml bolus of contrast material is injected manually in four seconds while an assistant controls the bulb of the blood pressure cuff. Filming is begun 0.5 seconds before the end of injection, and pressure in the cuff is released one second later. Rapid serial radiography at two per second for four seconds demonstrates both the arterial and venous components with contrast material flowing distally in the artery, while the venous components fill proximally, thus allowing differentiation between arteries and veins (Figs. 1, a and b). The fistula is examined in at least two projections, one at right angles to the first. The basic method can be altered to clarify overlapping vessels, fill only the
main draining vein, and demonstrate saphenous veinpopliteal artery fistulas.2 The contrast material is diluted to 20% to prevent the severe burning sensation produced in the hand when concentrated 60% methylglucamine diatrizoate is injected into an artery. Unpleasant side effects should be avoided because these patients may have recurrent problems requiring reexamination.
Clinical Material Between January 10, 1973 and September 23, 1976, 125 consecutive fistulograms of arteriovenous dialysis TABLE 1. Indications for Performing Venous Fistulographv
Technical problems Decreased arterial flow Increased venous resistance Maturation failure Difficult needle cannulation Absent pulsations Clots withdrawn during dialysis
Aneurysmal enlargement Cardiac failure Sepsis of uncertain etiology Pulmonary embolus
84
53 13 5
5
6 2 7
13 7 1
Baseline
6
Edema of extremity
3
Other
Total
4 125
196
Ann. Surg.
ANDERSON AND OTHERS
TABLE 2. Types of Arteriovenous Dialysis Fistulas Studied
54 29 16
Other
8
Anticubital fossa Side vein-side artery
Superficialized basilic vein
Saphenous Vein-Popliteal Artery
2
Bovine heterograft Forearm Arm Thigh Total
7
5
fistulas were performed in 82 patients. Patients ranged in age from six to 72 years with a mean age of 47 + 13 years. There were 36 males and 46 females. Fifty-five patients were studied once; 15 patients, twice; nine patients, three times; two patients, four times; and one Fistulography 33
23 7 3 10 7
2 1
13 8 3 2 3 4 11
Aneurysm Artery Vein Deep vein Extensive venous collaterals
6
No etiology for sepsis
7
Excessive flow rate Post banding of fistula Steal phenomena
4 3
Technical complication-extravasated contrast material Normal Baseline study Unexpected finding High flow ruled out Total
7
Deep vein identified for fistula construction
3
5
4 2
2 6
use
of 9 125
patient five times. Seven examinations were performed in 1973; 47 in 1974; 43 in 1975; and 27 in the first nine months of 1976. Criteria involved in selecting patients to undergo venous fistulography varied according to the preference of the attending vascular surgeon and his degree of experience with this technique. Anatomic configuration of the fistula was ascertained from the operative note and/or the fistulogram results. Fistulograms were interpreted prior to making a decision as to the clinical management of the patient and prior to any operation. The practical application of fistulography to clinical management of the patient was analyzed retroTABLE 5. Operations Following Fistulography
2 4 5
2
21 3 9 9
34
Revision of fistula Convert to end-to-end Anastomosis revision Segmental venous resection Superficialize deep vein Endarterectomy Thrombectomy Resect aneurysm Construct new vascular Arm fistula Bovine graft External shunt
2
125
Normal study-operation avoided, continued fistula Total
32 2 20 17 4 11
Technical complication-no information Normal baseline study (three post banding)
125
on
Complication Identified-operative correction Identified-died or transplanted before correction Not significant-continued use of fistula Not correctable-new vascular access site Maturation failure-new vascular access site
High flow Diagnosed-confirmed at operation and corrected Diagnosed-not confirmed at operation Not diagnosed-operation avoided Not diagnosed -normal flow measured at operation
2
Thigh
Bovine Thrombus in patent vein Maturation failure Dialysis needle malpositioned
TABLE 4. Application of Fistulographv Results to Clinical Management
Malpositioned needles corrected Eliminate fistula as source of sepsis
7
Arm
Significant vessel stenosis Artery Vein Anastomosis Insignificant vessel stenosis Artery Vein Anastomosis Vascular occlusion Vein Anastomosis
February 1978
99
Wrist Cephalic vein-radial artery End vein-side artery Side vein-side artery End vein-end artery
TABLE 3. Primary Diagnosis
o
access
6 9 10 3
1 1 4 site
Banded high flow fistula Explored for high flow-normal fistula Explored for low flow-normal fistula Closed fistula-recovered ATN
None Total
21 7
6 8 3
4
1 2 60 125
Vol. 187oNo. 2
ANGIOGRAPHY AND FISTULA MANAGEMENT
197
spectively. Patients were followed for at least two months after fistulography. Results
Indications for Fistulography Primary indications for performing fistulography are listed in Table 1. Although in some instances multiple reasons existed, the most important was selected to simplify tabulation of data. In 84 instances, technical problems were encountered during dialysis. Difficulty maintaining blood flow during dialysis was the most frequent problem. In seven instances, aneurysmal enlargement in close proximity to the arteriovenous fistula was noted. Four of these cases were obvious aneurysms in which the site of origin was in question, and in three cases it was difficult to distinguish a true aneurysm from subcutaneous hemorrhage and hematoma formation. In 13 cases of suspected high output cardiac failure due to excessive fistula flow, fistulograms were performed in hopes of documenting a rapid clearance of contrast material. Seven fistulograms were undertaken to ascertain the presence of vegetations or mural thrombi in the fistulas of patients with sepsis of undetermined etiology. One pa-
DAL
DVL
V
_
PAL
PVL / /
RA
RA
FIG. 3. A side cephalic vein (CV) to side of radial artery (RA) fistula (arrow) has prominent stenoses (arrowheads) of all four component vascular limbs, but has a proximal unobstructed cephalic vein. Since direct repair of the anastomosis was not indicated, the fistula was converted to an end of vein to end of artery anastomosis. The matured proximal cephalic vein could be used immediately for hemodialysis.
CV/ ,#
CV
1VRA
I
FIG. 2. An end cephalic vein (CV) to end of radial artery (RA) fistula
(arrow) in the wrist has insignificant stenoses of the venous limb (arrowheads).
tient was studied for a source of pulmonary embolism. Baseline fistulograms were performed in three patients after AVF banding for high output filure, in two patients to determine the exact anatomical configuration of the fistula prior to closure, and in one patient with a saphenous vein-popliteal artery fistula in which the position of the vein and the configuration of the ) Ianastomosis were of interest. A cause of upper I // edema was searched for in three patients. extremity Hand claudication, pain at the needle site, delineation of deep subcutaneous veins prior to attempting new fistula formation and an unknown indication accounted for the remaining four studies. Types of Arteriovenous Fistulas The types of arteriovenous dialysis fistulas studied are listed in Table 2. The majority of fistulas were of
198
ANDERSON AND OTHERS
Ann. Surg.
o
February 1978
Although occlusion of the fistula was found in 13 cases, it was often possible to delineate additional veins suitable for reconstructing the arteriovenous fistula. Thrombi in patent functional veins and failure of fistula maturation was identified in three and four cases, respectively. Performance of the fistulogram through needles which had been placed for routine dialysis identified malpositioned needles in 11 cases. Of the six aneurysms identified, two originated from the arteries supplying the fistula and four from the venous components. Veins located too deep in the subcutaneous tissue for ready vascular access were demonstrated five times and extensive venous collaterals were illustrated in two cases. Seven patients
NAN
PA
.., _ 2 ,
' \ ~~~~~~\
I
DAL UA
FIG. 4. Accurate localization of a single stenotic venous segment of limited extent (arrow) permitted revision by minimal dissection, segmental resection, and primary end-to-end anastomosis of the vein. CV = cephalic vein, RA = radial artery, PAL = proximal arterial limb, DAL = distal arterial limb, AN = anasto-
AN
PAL
cv
mosis.
the cephalic vein to radial artery type in the wrist (99 cases), although other configurations in the wrist (8 cases) such as basilic vein to ulnar artery fistulas and end of artery to side of vein fistulas were studied.
Primary Fistulogram Diagnosis The fistulography results are tabulated in Table 3. Interpretations of contrast studies were coordinated with clinical information from dialysis personnel. Simultaneous viewing of contrast studies by the radiologist and vascular surgeon proved beneficial in obtaining maximum information. To simplify presentation, only the main primary diagnosis is listed, realizing that secondary diagnoses were frequently made, and that recognition of all potential abnormalities is important for proper management. Significant vascular stenosis (>75% vascular lumen narrowing) was encountered in 33 patients. Insignificant vascular stenosis (
Venous angiography of subcutaneous arteriovenous (A-V) hemodialysis fistulas involves venous injection of radiographic contrast material which spreads throughout the venous system and into the arteries via the A-V anastomosis when blood flow to the extremity is temporarily occluded. Direct arterial cannulation is avoided. Subsequent restoration of blood flow with rapid sequential roentgenograms differentiates arteries from veins and identifies direction of fistula blood flow. A 44 month experience with 125 consecutive studies in 82 patients was performed with a 0.8% complication rate. Indications for fistulography included insufficient blood flow during dialysis (67%), cardiac failure (10%), aneurysms (6%), sepsis of undetermined site (6%) and other (11%). Roentgenographic findings identified vascular stenoses or occlusions (45%), malpositioned dialysis needles (11%), aneurysms (9%), unsuitable veins for dialysis (6%), absence of septic origin (5%), abnormal flow rates or patterns (5%), technically unsuitable studies (2%) and normal or baseline studies (17%). Information useful in planning clinical management of the patient was obtained in 88% of studies and fistula operations were performed in 65 patients (52%). Venous fistulography can be an effective and safe method of evaluating and planning correction of A-V dialysis fistula complications. T HE
SUBCUTANEOUS
ARTERIOVENOUS
From the Departments of Surgery, Radiology (Mailinckrodt Institute of Radiology), and Medicine (Chromalloy American Kidney Center); Washington University School of Medicine, St. Louis, Missouri
proved to be a safe, reliable and effective method of radiographically demonstrating both the arterial and venous components of the AVF by injecting the venous limb, thus avoiding arterial catheterization. It is now an integral part of our investigation of the malfunctioning AVF to determine if an anatomical complication exists, whether it can be repaired, and if so, which operative approach would best serve to correct the problem. This report reviews an experience with 125 consecutive examinations, analyzes the usefulness of the technique in patient management and presents representative cases to emphasize important findings. Technique Fluid injected into a passive system of tubes will spread evenly throughout the entire system; thus, when the arteriovenous pressure differential has been eliminated, a venous injection near the orifice of a fistula will allow contrast material to pass from the vein into the artery. With the patient supine, a blood pressure cuff is placed around the upper arm. Preliminary radiographs are obtained in both anteroposterior and lateral projections. The x-ray tube is centered to include the fistula, which is identified by a thrill in the area of the cutaneous scar, and major feeding and draining vessels. The skin is prepared antiseptically, and a 19 gauge scalp-vein needle is inserted into the proximal or distal venous limb of the anastomosis, so that the tip lies one centimeter away from and points toward the fistula. The needle is attached to a connecting tube and flushed with heparinized saline to prevent clotting. A 20
FISTULA
(AVF) is the preferred method for maintaining vascular access for chronic hemodialysis. Since first described by Brescia et al.' in 1966, the technique has had many modifications including the use of autogenous veins, human umbilical veins, synthetic material and processed bovine carotid arteries. Numerous articles have analyzed a wide variety of AVF and their functional usefulness for repeated cannulation. With the increased use of AVF, the complications have become more common. Vascular surgeons are being required to evaluate and revise these malfunctioning AVF to permit immediate use of mature veins and to conserve vessels for later use. Venous fistulography,4 a diagnostic tool developed at our institution, has been helpful in managing AVF complications. Since 1973, this method has Submitted for publication: June 13, 1977.
0003-4932-78-0200-0194-0115 © J. B. Lippincott Company
194
Vol. 187 . No. 2
ANGIOGRAPHY AND FISTULA MANAGEMENT
195
DAJ :..
.-
FIG. lb. Release of the prescuff clears contrast material first from the proximal radial artery, thus distinguishing it from the veins (V) which increasingly fills with contrast material. sure
FIG. la. With the arm blood pressure cuff inflated above arterial systolic pressure, contrast material injected into the cephalic vein spreads into communicating veins as well as the radial artery proximal (PAL) and distal (DAL) to the fistulous communication (arrow). A normal end cephalic vein (CV) to side of radial artery anastomosis is demonstrated. A = radial artery, V = cephalic vein.
ml syringe filled with 20% methyglucamine diatrizoate (60% methyglucamine diatrizoate diluted with sterile saline to 20%) is attached to the connecting tube. A cuff pressure of approximately 250 mmHg is applied to occlude all blood flow in the arm. When the cuff is properly inflated, the fistula thrill and arterial pulse disappear. A 20 ml bolus of contrast material is injected manually in four seconds while an assistant controls the bulb of the blood pressure cuff. Filming is begun 0.5 seconds before the end of injection, and pressure in the cuff is released one second later. Rapid serial radiography at two per second for four seconds demonstrates both the arterial and venous components with contrast material flowing distally in the artery, while the venous components fill proximally, thus allowing differentiation between arteries and veins (Figs. 1, a and b). The fistula is examined in at least two projections, one at right angles to the first. The basic method can be altered to clarify overlapping vessels, fill only the
main draining vein, and demonstrate saphenous veinpopliteal artery fistulas.2 The contrast material is diluted to 20% to prevent the severe burning sensation produced in the hand when concentrated 60% methylglucamine diatrizoate is injected into an artery. Unpleasant side effects should be avoided because these patients may have recurrent problems requiring reexamination.
Clinical Material Between January 10, 1973 and September 23, 1976, 125 consecutive fistulograms of arteriovenous dialysis TABLE 1. Indications for Performing Venous Fistulographv
Technical problems Decreased arterial flow Increased venous resistance Maturation failure Difficult needle cannulation Absent pulsations Clots withdrawn during dialysis
Aneurysmal enlargement Cardiac failure Sepsis of uncertain etiology Pulmonary embolus
84
53 13 5
5
6 2 7
13 7 1
Baseline
6
Edema of extremity
3
Other
Total
4 125
196
Ann. Surg.
ANDERSON AND OTHERS
TABLE 2. Types of Arteriovenous Dialysis Fistulas Studied
54 29 16
Other
8
Anticubital fossa Side vein-side artery
Superficialized basilic vein
Saphenous Vein-Popliteal Artery
2
Bovine heterograft Forearm Arm Thigh Total
7
5
fistulas were performed in 82 patients. Patients ranged in age from six to 72 years with a mean age of 47 + 13 years. There were 36 males and 46 females. Fifty-five patients were studied once; 15 patients, twice; nine patients, three times; two patients, four times; and one Fistulography 33
23 7 3 10 7
2 1
13 8 3 2 3 4 11
Aneurysm Artery Vein Deep vein Extensive venous collaterals
6
No etiology for sepsis
7
Excessive flow rate Post banding of fistula Steal phenomena
4 3
Technical complication-extravasated contrast material Normal Baseline study Unexpected finding High flow ruled out Total
7
Deep vein identified for fistula construction
3
5
4 2
2 6
use
of 9 125
patient five times. Seven examinations were performed in 1973; 47 in 1974; 43 in 1975; and 27 in the first nine months of 1976. Criteria involved in selecting patients to undergo venous fistulography varied according to the preference of the attending vascular surgeon and his degree of experience with this technique. Anatomic configuration of the fistula was ascertained from the operative note and/or the fistulogram results. Fistulograms were interpreted prior to making a decision as to the clinical management of the patient and prior to any operation. The practical application of fistulography to clinical management of the patient was analyzed retroTABLE 5. Operations Following Fistulography
2 4 5
2
21 3 9 9
34
Revision of fistula Convert to end-to-end Anastomosis revision Segmental venous resection Superficialize deep vein Endarterectomy Thrombectomy Resect aneurysm Construct new vascular Arm fistula Bovine graft External shunt
2
125
Normal study-operation avoided, continued fistula Total
32 2 20 17 4 11
Technical complication-no information Normal baseline study (three post banding)
125
on
Complication Identified-operative correction Identified-died or transplanted before correction Not significant-continued use of fistula Not correctable-new vascular access site Maturation failure-new vascular access site
High flow Diagnosed-confirmed at operation and corrected Diagnosed-not confirmed at operation Not diagnosed-operation avoided Not diagnosed -normal flow measured at operation
2
Thigh
Bovine Thrombus in patent vein Maturation failure Dialysis needle malpositioned
TABLE 4. Application of Fistulographv Results to Clinical Management
Malpositioned needles corrected Eliminate fistula as source of sepsis
7
Arm
Significant vessel stenosis Artery Vein Anastomosis Insignificant vessel stenosis Artery Vein Anastomosis Vascular occlusion Vein Anastomosis
February 1978
99
Wrist Cephalic vein-radial artery End vein-side artery Side vein-side artery End vein-end artery
TABLE 3. Primary Diagnosis
o
access
6 9 10 3
1 1 4 site
Banded high flow fistula Explored for high flow-normal fistula Explored for low flow-normal fistula Closed fistula-recovered ATN
None Total
21 7
6 8 3
4
1 2 60 125
Vol. 187oNo. 2
ANGIOGRAPHY AND FISTULA MANAGEMENT
197
spectively. Patients were followed for at least two months after fistulography. Results
Indications for Fistulography Primary indications for performing fistulography are listed in Table 1. Although in some instances multiple reasons existed, the most important was selected to simplify tabulation of data. In 84 instances, technical problems were encountered during dialysis. Difficulty maintaining blood flow during dialysis was the most frequent problem. In seven instances, aneurysmal enlargement in close proximity to the arteriovenous fistula was noted. Four of these cases were obvious aneurysms in which the site of origin was in question, and in three cases it was difficult to distinguish a true aneurysm from subcutaneous hemorrhage and hematoma formation. In 13 cases of suspected high output cardiac failure due to excessive fistula flow, fistulograms were performed in hopes of documenting a rapid clearance of contrast material. Seven fistulograms were undertaken to ascertain the presence of vegetations or mural thrombi in the fistulas of patients with sepsis of undetermined etiology. One pa-
DAL
DVL
V
_
PAL
PVL / /
RA
RA
FIG. 3. A side cephalic vein (CV) to side of radial artery (RA) fistula (arrow) has prominent stenoses (arrowheads) of all four component vascular limbs, but has a proximal unobstructed cephalic vein. Since direct repair of the anastomosis was not indicated, the fistula was converted to an end of vein to end of artery anastomosis. The matured proximal cephalic vein could be used immediately for hemodialysis.
CV/ ,#
CV
1VRA
I
FIG. 2. An end cephalic vein (CV) to end of radial artery (RA) fistula
(arrow) in the wrist has insignificant stenoses of the venous limb (arrowheads).
tient was studied for a source of pulmonary embolism. Baseline fistulograms were performed in three patients after AVF banding for high output filure, in two patients to determine the exact anatomical configuration of the fistula prior to closure, and in one patient with a saphenous vein-popliteal artery fistula in which the position of the vein and the configuration of the ) Ianastomosis were of interest. A cause of upper I // edema was searched for in three patients. extremity Hand claudication, pain at the needle site, delineation of deep subcutaneous veins prior to attempting new fistula formation and an unknown indication accounted for the remaining four studies. Types of Arteriovenous Fistulas The types of arteriovenous dialysis fistulas studied are listed in Table 2. The majority of fistulas were of
198
ANDERSON AND OTHERS
Ann. Surg.
o
February 1978
Although occlusion of the fistula was found in 13 cases, it was often possible to delineate additional veins suitable for reconstructing the arteriovenous fistula. Thrombi in patent functional veins and failure of fistula maturation was identified in three and four cases, respectively. Performance of the fistulogram through needles which had been placed for routine dialysis identified malpositioned needles in 11 cases. Of the six aneurysms identified, two originated from the arteries supplying the fistula and four from the venous components. Veins located too deep in the subcutaneous tissue for ready vascular access were demonstrated five times and extensive venous collaterals were illustrated in two cases. Seven patients
NAN
PA
.., _ 2 ,
' \ ~~~~~~\
I
DAL UA
FIG. 4. Accurate localization of a single stenotic venous segment of limited extent (arrow) permitted revision by minimal dissection, segmental resection, and primary end-to-end anastomosis of the vein. CV = cephalic vein, RA = radial artery, PAL = proximal arterial limb, DAL = distal arterial limb, AN = anasto-
AN
PAL
cv
mosis.
the cephalic vein to radial artery type in the wrist (99 cases), although other configurations in the wrist (8 cases) such as basilic vein to ulnar artery fistulas and end of artery to side of vein fistulas were studied.
Primary Fistulogram Diagnosis The fistulography results are tabulated in Table 3. Interpretations of contrast studies were coordinated with clinical information from dialysis personnel. Simultaneous viewing of contrast studies by the radiologist and vascular surgeon proved beneficial in obtaining maximum information. To simplify presentation, only the main primary diagnosis is listed, realizing that secondary diagnoses were frequently made, and that recognition of all potential abnormalities is important for proper management. Significant vascular stenosis (>75% vascular lumen narrowing) was encountered in 33 patients. Insignificant vascular stenosis (
