Letters

to the

U Complication Film Cerebral From: David

Editor

Rates of DSA Angiography

and

simple comparison of complication rates with DSA and from studies of heterogeneous groups with conventional techniques is inaccurate and misleading.

Conventional

M. Pelz, MD, FRCPC

Department

of Diagnostic

Radiology,

University

Box 5339, 339 Windermere Canada N6A 5A5

Road,

London,

Ontario,

1.

Waugh JR. Sacharias N. Arteriographic era. Radiology 1992; 182:243-246.

2.

Hankey

3.

should

be congratulated

on

their

efforts

to lower

Leow ease:

cerebral

4.

angiography

is exemplary.

Attributing

collective

heterogeneous and in their The only rial

findings

in their definitions study they

DSA with

of these

studies

aims, in the types of complications.” found that directly

conventional

angiography

because

they

of patients

studied

compared

intraarte-

(4) actually

found

a

mean volume of contrast material used with DSA (88 mL) exceeded that used with conventional angiography (67 mL). Waugh and Sacharias have omitted a study by Dion et al (5),

conventional of permanent

technique. neurologic

Earnest deficit

JA.

Cerebral

risk

in dis-

5.

Earnest

F, Forbes

angiography:

C, Sankok

prospective

BA, et al.

Complications

assessment

of risk.

AJR

of cerebral 1984;

142:247-253.

.

Balloon

Angioplasty

From: Paul H. Gibson, Department

versus

Surgery

MD

of Cardiology,

10010 Kennerly

St Anthony’s

Road,

St Louis,

MO

Medical

Center

63128

Editor: As an active practitioner of peripheral interventional procedures), I would cle by Johnston (1) in the June issue

are

higher major complication rate with intraarterial DSA (7%) than with conventional angiography (4%). It has been postulated that use of lower volumes of contrast material with DSA may result in increased safety; however, in this study, the

who prospectively evaluated 1,002 dures and found a risk of permanent More than 95% of these procedures

RJ. Cerebral angiographic Stroke 1990; 21:209-222. angiography for cerebrovascular

disease.

this

recent and complete being the study by Hankey et al (2), which is a summary of eight prospective and seven retrospective Seties. Hankey et al caution that “it is important not to overestithe

K, Murie

in the DSA

Carotid digital subtraction angiography: the comparative roles of intraarterial and intravenous imaging. Surgery 1984; 96:909-917. Dion JE, Gates PC, Fox AJ, Barnett HJM, Blom RJ. Clinical events following neuroangiography: a prospective study. Stroke 1987; 18: 997-1004.

6.

the

low complication rate to digital imaging technology is, however, somewhat misleading. The authors cite stroke rates of 1 % (2) and 2.4% (3) with conventional film cerebral angiography from two recent studies. Both of these studies were reviews of the literature, the more

mate

CP, Sellar

complications

the risks. BrJ Surg 1988; 75:428-430. Reilly LM, Ehrenfeld WK, Stoney RJ.

risk of angiography through the use of DSA. Their low permanent neurologic deficit (stroke) rate (0.3%) in patients who underwent

CJ, Warlow

mild cerebrovascular

Editor: In the January 1992 issue of Radiology, Waugh and Sacharias (1) reported the prevalence of all types of complications associated with intraarterial digital subtraction angiography (DSA) in a major Australian teaching hospital and compared their complication rates with those from the literature. Drs Waugh and Sacharias

film

References

of Western

Ontario P0

those

cerebral angiography proceneurologic deficit of 0.4%. were performed with a

et al (6) reported a 0.33% rate in their review of 1,517 proce-

angioplasty (and other like to respond to the artiof Radiology, in which he analyzed the long-term outcome of femoral and popliteal angioplasty at his institution. He found a long-term patency rate at 5 years of only 53% for those procedures and concluded that a trial comparing the long-term outcome for popliteal bypass surgery and angioplasty is advisable. An implication of this conclusion is that if such a trial docu-

mented

that a higher

bypass lieve

surgery, this

necessary

is an

5-year

this

would

erroneous

for the

1. A peripheral

bypass

Most

occlusions

will become

within

the

first

femoral few

the

rate was achieved preferred

conclusion

following

the future.

patency be

and

that

I be-

such

a trial

is not

reasons.

procedure arteries after

limits with

obliterated

years

with

procedure.

a patient’s

stenotic

by a dense a successful

fibrotic

bypass

process

procedure.

that the statistically

for repeat angioplasty or bypass surgery. 2. Johnston reveals little about the mode of failure in these patients, that is, if a total occlusion once recanalized returns as an isolated stenosis 4 years later, it is still probably best treated with a repeat interventional procedure.

rologic

deficit

significant

after

cerebral

risk factors angiography

for permanent are

as follows:

neupreex-

isting cerebrovascular disease with symptoms, use of large volumes of contrast material, and operator experience. Other factors predisposing to complications indude older patient age, concomitant medical problems, increasing number of catheter exchanges, and

longer

procedure value than

be of more A prospective with conventional prove

908

that

the

times. Attention to these risk the choice of imaging technology.

randomized cerebral use

of DSA

trial

comparing

angiography alone

can

would reduce

factors

may

intraarterial DSA be necessary to

complications.

A

recanalization

of these

bypassed

in the future

It

is unlikely enable

technique

in

total

many of which were likely performed in the conventional film angiography era. Hankey et al cited these two prospective studies as being “superior in terms of methodology and analysis,” and the morbidity figures of these studies cornpare favorably with those of Waugh and Sacharias. The studies of Earnest et al (6) and Dion et al (5) have shown

dures,

that any interventional

options

or short

arteries,

thereby

will con-

signing the patient to repeat surgeries as the only mode of therapy when the artery graft is no longer patent. The converse is not true. Patients who undergo angioplasty and who have restenosis at 3 or 5 years are still almost always candidates

3. Long-term success rates for interventional procedures (ie, angioplasty or thrombolysis) performed in a failing graft are much lower than those for the same procedures performed in a native artery. 4. It may not be in the patient’s best interest to use saphenous

vein

as graft

material

because

it may

preclude

the patient

from dure

undergoing in the future.

5. Even

if surgery

patency,

term

a complete as a first

this

gain

documented

higher

with

procedures

surgical

coronary

bypass

procedure

provided

would

be substantially

morbidity

and mortality

(when

grafting

compared

greater

offset

diologist,

proce-

has limited

responsibilities

long-

by the

interventional

enhanced

procedures).

liability

and

responsibility

with the patient. Primary care

physicians,

cific obligations

to

to communicate

as defined

ogists.

plasty (or another bypass procedure

The primary

care physician,

therefore,

between

radiologist

the

and performing

a

1.

Johnston

KW.

of balloon 2. 3.

Femoral

and

angioplasty.

popliteal

Radiology;

arteries:

reanalysis

of results

1992; 183:767-771.

Wilson SE, Veith FJ, Hobson RW, Williams RA. Vascular surgery principles and practice. New York: McGraw Hill, 1987; 348, 366. Doubilet P, Abrams HL. The cost of underutilization. N EnglJ

Med 1984; 310:95-102.

Dr

Johnston

responds:

I agree with some of the points made in Dr Gibson’s letter. In particular, percutaneous transluminal angioplasty (PTA) is often performed at an earlier stage in the patient’s disease. In-

deed,

the patient

profile femoral

and the extent popliteal PTA

of disease

reported

in

my article about is in sharp contrast to those of patients that normally undergo arterial reconstructive procedures at my institution. In most cases, angioplasty and surgery are not competitive treatments but are complementary. The long-standing collaboration and cooperation between the interventional radiologists and vascular surgeons at my institution attest to the importance we attach to the selection of the treatment that is optimum for each patient. On the basis of my experience and the results published by others, I have concluded that good long-term results of femoral popliteal PTA are obtained only for PTA of stenoses with good runoff. I do not imply that PTA should not be considered in patients who have a low chance of long-term success, especially if the risks and benefits of alternative treatment tech-

niques

are also low. I suggest that PTA and surgery should be carefully in similar patients not to assess just the late patency also the relative safety and cost of the procedures.

Thus, compared rate but

a direct

the

relationship

patient.

with

They

have

the patient,

the patient

(2,3).

Conversely,

the

view

spe-

to maintain

decisions regarding

all relevant

courts

have

duty

to make disclosure

management, to provide reasonable formed consent, and to communicate

about in-

diagnoses

to

the responsibility

of

the consultant as limited to communication with and advice the clinicians (4). In fact, courts have held that augmentation the consultant’s role may interfere with the relationship between

the

These

primary

court

care

physician

and

no longer

may act to safeguard

decisions

Many

women

the

“consultant” rectly with

References

re-

directly

by the courts,

6. Angioplasty and other nonsurgical interventional procedures can legitimately be performed at an earlier stage in the patient’s disease because of the substantially lower morbidity and mortality associated with these procedures. In conclusion, angioplasty and/or other current interventional techniques should be used in a complementary fashion with surgical bypass in the treatment of patients with peripheral vascular disease. Regarding these procedures as competitors does patients with this disease a disservice. If a patient is a candidate for either procedure and the angioplasty procedure can be performed at a lower risk for the patient, then data exist to support treating that patient in all cases first with angio-

interventional technique) at a later date if necessary.

with

to patient care (2). Now, however, a number of radioloare involved in freestanding mammography centers and, additionally, may perform biopsy of nonpalpable lesions. Consequently, and under these circumstances, the radiologist has

(2,3) associated with

as a consultant,

gard gists

now

the

patient

are self-referred and

to of

(5,6).

radiol-

for mammography.

will not act as a shield

patient.

Consequently,

the

radiologist must be prepared to communicate the patient to enable her to make an informed

sion. This may an appropriate

entail explanation of the findings specialist for further evaluation. increasing numbers of cases relating

and

di-

deci-

referral

to

Despite to information disclosed relative to informed consent, the courts have not yet applied these arguments to the radiologist (5). Future courts, however, will likely find this theory persuasive as the distinction between the duties of the consultant and the clinician becomes nebulous. Thus, the radiologist must be prepared to accept primary care responsibilities for the patient to avoid potential liability in a malpractice situation. References 1. 2.

Kline TJ, Kline TS. Radiologists, communication, and resolution a medicolegal issue. Radiology 1992; 184:131-134. Townsend v Turk, 266 Cal Rptr 821, 218 Cal App 3d 280 (Cal App

5: 4

Dist 1990). 3.

Mahannah

237 Cal Rptr

v Hirsh,

140,

191 Cal App

3d 1523

(Cal

School

of

App

Dist 1987). 4. 6.

Townsend Townsend Mahannah

U

US

5.

v Turk, v Turk,

266 Cal Rptr 821,824. 266 Cal Rptr 821,826. v Hirsh, 237 Cal Rptr 140, 145.

Evaluation

of Renal

Colic

From: F. Graham Department Medicine 300 Pasteur

Sommer, MD of Radiology, Drive,

Stanford

Stanford,

University

CA 94305-5105

Editor:

I am writing

K. Wayne

Johnston,

Division of Vascular 200 Elizabeth Street,

U

Hospital

in regard to the recent article by Haddad et al in the July 1992 issue of Radiology (1), which compared the effectiveness of ultrasound (US) combined with kidney, ureter, bladder (KUB) radiography with that of intravenous urography (IVU) in the initial evaluation of renal colic. I wish to emphasize an important technical point with respect to the US evaluation of renal colic. Although Haddad et al confirm the effectiveness of KUB radiography and US indicated in some prior studies (2,3), results of some trials have indicated a substantial problem with false-negative results (4,5). I evaluated these studies in an attempt to analyze this van-

PA 19096

ability

MD

Radiologists,

Surgery, Toronto,

Toronto Ontario,

General Canada

Communication,

and

Hospital M5G 2C4

Resolution

5

From: Tess

J.

Kline,

Department

JD,

and

Tilde

S. Kline,

of Pathology,

100 Lancaster

Avenue,

Lankenau

Wynnewood,

MD

Editor: In our article in the July 1992 issue of Radiology (I) we stated that “[T]he radiologist should be cautious of direct communication with the patient except in emergency. . . . [Cjonsultant specialists rarely enter into a relationship similar to that of the primary care physician and the patient.” Traditionally, the ra-

Volume

185

Number

#{149}

3

and

have

noticed

that

the

importance

of patient

hydra-

tion before performing sonography my colleagues and I described this

has not been stressed since technique in 1984 (2). Patients with renal colic are often dehydrated, and I think it is important to make the point that before performing sonography for diagnosis of renal colic-primarily on the basis of asymmetric

drated

pelvicaliceal

orally

or

intravenously

dilatation-the for

patient optimal

results.

must

be

In one

Radiology

hystudy

#{149} 909

1