U

The

Preventing Roll-over

Pneumothorax Technique

after

Lung

known

Biopsy:

From: and

Fred A. Birnbeng, MD Hoag Memorial Hospital

Newport

Beach,

Editor:

none

of whom

required

a chest

tube.

Our technique was developed from experience gained from chest-tube placement after pneumothorax. We have found that apposition of the pleurae is very important. In addition, review of computed tomognaphic (CT) scans demonstrated hypenemia in the dependent portion of the lung. In the supine patient, this would normally be the dorsal aspect of the lung. Furthermore, simple physics dictates that air escaping from a dependent puncture would migrate away from the hole to the nondependent portion of the lung. Use of a similan technique in dogs has been reported in the pulmonary litenatune (3). We therefore began to turn patients in a direction opposite to that of the needle stick immediately after needle removal. If the needle is placed from an anterior approach with the patient supine, the patient is immediately and quickly turned into a prone position. If the needle is placed from a posterior approach with the patient prone, the patient is immediately rotated supine. The patient is then left in this position for 3 hours. This procedure, combined with the standard technique of interrupting respiration during manipulation of the needle and attempting to limit the number of pleural passes, has significantly reduced our complications to four very small asymptomatic pneumothoraces in the last 80 patients. Although the majority of the lung biopsies were done with 22gauge Westcott needles and were performed with a single pass, several of these biopsies were performed with larger needles under CT guidance and necessitated several passes. Still, no significant pneumothonaces have been encountered. Our biopsy technique is otherwise not changed. The first author is experienced with this procedure, having performed over 1,000 lung biopsies. Although a large body of data on experience with this new technique

provement this method

is not

yet

available,

we

believe

that

the

dramatic

References

2. 3.

Zidulka

A, Braidy

pneumothorax

TF, progression

Rizzi

MC,

NR. Percutaneous transAJR 1989; 152:451-455. needle biopsy. Radiology

Shiner

in dogs.

RJ. Am

Rev

Position Respir

we

investigated

(2).

According

may Dis

stop 1982;

126:52-55.

of

Femoral

Capital

From: Peter Higer, MD Department, Deutsche Klinik Aukammallee 33, D-6200 Wiesbaden, Germany H.

MRI

f#{252}r Diagnostik Federal Republic

of

Editor: In an article that appeared in the April 1989 issue of Radiology, Turner et al (1) describe, under the name “femonal capital osteonecrosis,” diffuse abnormalities that are in fact not included in the diagnostic group of osteonecnoses but are 282

#{149} Radiology

a follow-up

and

of this

that

radiobogic

of up

study

course

diffuse,

pub-

osteoporosis, period

in

disease:

of algodystrophy

simultaneously

of transient

findings

period

was

which viously

is characterized involved area.

cal

and

which to 9 months the

previously

(3), we established

focal,

and

residual.

obviously

symptoms

too

had

short

to discover

the

residual

stage,

by small sclerotic islets within the preAt the time of the residual stage, clini-

completely

disappeared

in our

study.

We performed a biopsy in only one case at the beginning of our study. Osteonecrosis was not found, but rarefaction of bone trabeculae was. We also could not observe any transformation into avascular femoral head necrosis, although the focal stage shows a vague similarity. In contrast to the classic osteonecroses, transient osteoponosis is by definition transient and is not associated with an increased risk for osteoarthnosis, nor does it disable the patient subsequently. Peculiarly, the theory of transformation of transient osteoporosis into femoral head necrosis has made its way into the literature, although clinical evidence for this phenomenon is lacking. To my knowledge, there is no reported case that documents this. I suggest that we refrain from future reference to this

concept

until

adequate

evidence

has

been

presented.

De-

spite the authors’ findings of osteonecrotic changes, there are already enough synonyms for the clinical entity of transient osteoporosis, and there is certainly no adequate reason why the term “femoral capital necrosis” should be added to this collection. References 1.

Turner DA, JP. Femoral abnormalities

2.

Higer

3.

Templeton AC, Seizer capital osteonecrosis: without focal lesions.

HP,

Dr Turner

U

PM, Rosenberg AG, Petasnick MR finding of diffuse marrow Radiology 1989; 171:135-140.

J, Pedrosa

Grimm

P. Apel R, Bandilla K. Transient oshead necrosis? early diagnosis via MRI. 1989; 150:407-412. M, Bensasson N, Perez C, Dreiser R, Forest osteoporosis. Skeletal Radiol 1977; 2:1-9.

teoporosis or femoral Fortschr Rontgenstr Lequesne M, Kerboull A. Partial transient

responds:

In the article referred to by Dr Higer (1), we reported that findings at magnetic resonance (MR) imaging attributed to bone marrow edema (low signal intensity on short repetition time [TR]/echo time [TEl spin-echo images and iso- or hyperon

long

TRITE

images)

may

be

seen

in the

femoral

head and neck and the intertrochantenic region in femorab capital osteonecrosis in the absence of the focal abnormalities considered to be characteristic of that condition (2-1 1). It is my understanding that Dr Higer objects to our conclusion on the grounds that similar MR findings have been reported in transient osteoporosis. We believe that the diagnosis of femoral capital osteonecrosis

was

firmly

established

in

the

ries. In three hips the diagnosis nation of core biopsy specimens; which

Osteonecrosis

during

variant

We

All of the observations and images presented by Turner et al fit into our classification. For example, Figures 1, 2a-2c, 3a, and 3b are typical of the diffuse stage. Figures 2d, 2e, and 3c are typical of the focal stage. Unfortunately, their observation

diagnosis U

cases

to the

stages

one

syndrome).

of eight

clinical

intensity

im-

in our pneumothonax rate warrants consideration for preventing pneumothorax after lung biopsy.

Perlmutt LM, Johnston WW, Dunnick thoracic needle aspiration: a review. Westcott J. Percutaneous transthoracic 1988; 169:593-601.

a study

three

CA 92663

osteoporosis,

as Sudeck

described

According to recent reviews (1,2), the pneumothorax rate for percutaneous lung biopsy is relatively constant at 10%-40%. This has changed little over many years of reporting. We have developed a technique that significantly reduces the mcidence of pneumothorax. Previously, our pneumothorax rate (in 300 patients) was approximately 20%; approximately half of those patients required chest tubes. With this new procedune, we had only four small pneumothonaces in 80 patients

1.

known

lished

Douglas M. Cassel, MD, Department of Radiology, Presbyterian 301 Newport Boulevard,

(5%),

as transient

(also

was

based

on

findings

six

hips

included

in

our se-

was made at histologic examiin the remaining three, the at serial

MR

examinations,

progression to focal findings reported to be highly specific for femonal capital osteonecrosis (4,8). Moreover, our observations are not unique: Mitchell et ab have illustrated, without comment, a single similar case (1 1). We pointed out in our article that identical MR imaging findings have been reported in transient osteoporosis (12,13). However, this does not mean, as suggested by Dr Higer, that similar

necrosis. is not stress, myelitis

demonstrated

MR

findings

It means

cannot

only

specific. Indeed, and insufficiency (17).

that

be

the

it has also fractures

seen

“bone

in

femoral

capital

osteo-

marrow

edema

pattern”

been reported in traumatic, (14-16), as well as in osteo-

January

1990