Talc Pleurodesis: Talc Slurry Versus Thoracoscopic Talc Insufflation in a Porcine Model Robbin G. Cohen, MD, William W. Shely, MD, Suzanne E. Thompson, DVM, Jeffrey A. Hagen, MD, Charles C. Marboe, MD, Tom R. DeMeester, MD, and Vaughn A. Starnes, MD Division of Cardiothoracic SurgeD,, Department of SurgeD', University of Southern California School of Medicine, Los Angeles, California; and Ethicon Endo-Surgery Institute, Cincinnati, Ohio

Background. Pleurodesis us ing both talc slurry and thoracoscopic talc insuffiation has been shown to be cl inically effective. This study compares these two mo- dalities of pleural talc instil lation in an animal model.

Methods. Eleven immature pigs underwent general endotracheal anesthesia. On one side, a slurry of 5 g sterile United States Pharmacopeia talc in 50 mL of saline solution was insti l led through a thoracostomy tube. On the other side, the lung was deflated and 5 g of dry talc was insuffiated under thoracoscopic visualization. The animals were sacrificed 30 days later, and the quality of pleural adhesions was graded from 0 to 2 (0 = absent; 1 = light; 2 = dense) in each of six regions of each hemitho- rax. The distribution of adhesions on each side was graded from 0 to 6, according to the number of areas that contained adhesions.

Results. One animal died of anesthetic complications. Among the survivors, adhesions produced by both meth- ods were dense and diffuse in 8 of 10 animals, and light and diffuse in 1 animal. One animal had light or absent adhesions on the talc slurry side, and dense and diffuse adhesions on the thoracoscopic talc insufflation side. There was no difference between the techniques for density of adhesion scores (talc slurry, 9.9 - 2.2; thoraco- scopic talc insufflation, 10.0 -+ 2.5) or distribution of adhesion scores (talc slurry, 5.5 + 1.0; thoracoscopic talc insufflation, 5.8 --- 0.4) (p > 0.1).

Conclusions. Effective pleurodesis in a porcine model can be obtained with either talc slurry or thoracoscopic talc insufflation.

(Ann Thonw Surg 1996;62:1000-4)

T alc p leurodes is is extremely effective for the treat- ment of chronic pleural effusions and selected cases

of recurrent pneumothorax [1]. Whereas talc can be insti l led successfully into the pleural space in slurry form through a thoracos tomy tube, adminis t ra t ion by thoraco- scopic insuffiation recently has become popula r [2, 3]. Though effective, the thoracoscopic approach frequent ly requires general anesthesia and s ingle- lung ventilation, with the potent ial for increased morbid i ty and mortal i ty as well as increased cost [4]. This s tudy compares the effectiveness of p leurodes is result ing from thoracoscopic talc insufflation (TTI) with that obta ined by talc slurry (TS) through a thoracos tomy tube in a porcine model.

Materia l and M e t h o d s

All animals received humane care in accordance with the "Guide for the Care and Use of Laboratory Animals" publ i shed by the Nat ional Insti tutes of Heal th (NIH publicat ion 85-23, revised 1985).

Eleven immature pigs (weight 35 to 50 kg) underwent bi la teral talc p leurodes is under general endotracheal anesthesia. In each animal, TTI was randomly ass igned to be per formed on one side and TS on the other.

Presented at the Thirty-second Annual Meeting ot The Society of fho- racic Surgeons, Orlando, FL Jan 29-31, 1996.

Address reprint requests to Dr Cohen, USC Healthcare Consultation Center, 1510 San Pablo St, #415, Los Angeles, CA 90033.

We per formed TS first. On this side, a 2-cm incision was made and the pleural space was entered in the fifth or sixth intercostal space. A 10-mm thoracoscope was placed through the incision without deflating the lung, and the pleural space was explored to exclude existing adhes ions or p leura l disease. The scope was removed, and a 28F thoracos tomy tube was placed through the same incision. A slurry of 5 g talc (magnes ium silicate) in 50 mL of sterile saline solution was insti l led into the pleural space through the tube with a ca the te r - t ipped syringe. The tube was f lushed with another 50 mL of saline and c lamped. The animal was then rota ted into the dorsal, sternal, and right and left decubi tus posi t ions every 15 minutes for 2 hours. The thoracostomy tube was unc lamped and placed to 20 cm suction. To ensure that the TS side was indis t inguishable from the TTI side, we made a second incision and closed it 5 cm anter ior and super ior to the thoracos tomy tube site.

Identical skin incisions were made on the contralateral hemithorax. After selective deflation of the lung on this side, a 10-mm thoracoscope was inser ted through a por t in the inferior incision. The pleura l space was explored to confirm that the lung was col lapsed and to exclude preexist ing pleural disease or adhesions. Using a bulb syringe, 5 g of dry sterile talc was then insufflated into the pleural space through the super ior incision under thora- coscopic vision. After the thoracoscope was replaced with

© 1996 by The Society ot Thoracic Surgeons 0003-4975/96/$15.00 Published by Elsevier Science lnc P[I S0003-4975(96)00488-2

Ann Thorac Surg COHEN ET AL 1001 1996;62:1000-4 TALC PLEURODESIS: PORCINE MODEL

a 28F thoracostomy tube in the inferior incision, we reexpanded the lung and obtained a chest roentgeno- gram to ensure that the lungs were inflated bilaterally. The animals were then allowed to recover, and both chest tubes were removed. Buprenorphine, 0.01 to 0.05 mg/kg, was administered as an analgesic every. 8 to 12 hours postoperatively for 72 hours.

Thirty days later, a second chest roentgenogram was obtained. The animals then were sacrificed and autop- sied by an investigator who was b l inded to which hemithoraces received TS and which ones were treated with TTI. The ventral chest wall and s ternum were removed, and the pleural spaces were evaluated for the distribution of adhesions (DA) by assigning one point for each of six areas of the pleural space in which substantial adhesions were present (apical, diaphragmatic, medias- tinal, anterior, lateral, and posterior). The maximum possible DA score was 6. A rating of "diffuse" was given for a DA score of 5 or greater on a given side.

The quality of adhesions (QA) in each of six areas was also determined, by grading on a scale of 0 to 2 as follows: 0 = absent; 1 - light (able to dissect blunt ly without tearing the lung); and 2 - dense (lung tears with blunt dissection; sharp dissection required to take down adhe- sions). The maximum QA score was 12. An overall rating of "dense" was given for a QA score of 10 or greater on a given side, and "light" for a QA score of 4 to 10. Pleurodesis was considered to have failed if the QA score was less than 4 or if the DA score was less than 5. Sections of the lung and chest wall containing adhesions were submit ted for histologic examination.

Data were expressed as mean + standard deviation. The paired Student 's t test was used to determine the differences between each group. A p value less than 0.05 was considered statistically significant.

Results

Twenty-two pleurodesis procedures were performed on 11 animals (11 TS, 11 TTI). One animal died immediately postoperatively of pneumothorax resulting from a mal- functioning chest tube. All other animals survived the procedure and recovered without complications. Chest roentgenograms obtained after pleurodesis and 1 month postoperatively showed full expansion of the lungs bilat- erally in all animals.

Adhesions produced bv both methods were dense and diffuse in 8 of 10 animals, and light and diffuse in 1 animal. One animal had light or absent adhesion~ on the TS side (DA +- 3, QA - 5), and dense and+ diffuse adhesions on the TTI side. There was m, ,ignificant difference between the techniques with respect to the quality of adhesion scores (TS, 9.9 ± 2.2; TTI, 10.0 ._-. 2.5) or the distribution of adhesion scores (TS, 5.5 ~ 1.0; TTI, 5.8 ± 0.4) (p --> 0.1). The localized absence of adhesions, when it occurred, was noted most frequently on the dorsal diaphragmatic surface. This was observed on both sides in 2 animals, on the TS side in I animal, and on the TTI side in 1 animal. In addition, a focal absence of adhesions tended to occur in areas where the collapsed

lung was not lifted to allow exposure to insufflated talc on the TTI side.

Histologically, both sides showed obliteration of the pleural space by a florid foreign-body giant cell response and developing fibrosis.

Comment

The intrapleural instillation of talc for producing pleural adhesions was first described in the laboratory and clinical setting by ge thune [5] in 1935, who used it as a prel iminary to lobectomy. Since then, talc has been discussed extensively regarding its mechanism of action, mode of administration, effectiveness, and potential tox- iciW as a pleural sclerosing agent.

Animal studies have shown that the intrapleural appli- cation of talc by either slurry or poudrage causes visceral pleural thickening with macrophage infiltration, foreign- body reaction, and fibroblast proliferation, with subse- quent pleural fibrosis [1, 6, 7]. These findings were also present in this study, although only mild to moderate fibrosis was seen. This latter result may be due to the short follow-up (30 days) in this study as compared with other studies.

The effectiveness of talc for pleurodesis has been documented both clinically and in the laboratory. Bre- sticker and associates [8] found that talc was equal to mechanical abrasion and superior to tetracycline, the argon beam coagulator, and the Nd:YAG laser in produc- ing pleural adhesions in dogs. Har tman and colleagues [9] compared insuffiated talc with tetracycline and bleo- mycin pleurodesis in patients with mal ignant pleural effusions and found consistently superior results with talc. Kennedy and Sahn [1] reviewed the literature from 1958 to 1994 and calculated a cumulative success rate of 91% among 723 patients undergoing talc pleurodesis for pleural effusions. The success rate for TS in the reviewed studies ranged from 80% to 100%, compared with 90°/, to 100% for talc poudrage. This fairly extensive clinical experience is consistent with our laboratory findings, which showed comparable results between these modes of talc delivery. Both the quality and distribution of adhesions seem to be acceptable with both techniques. We found an occasional lack of adhesions on the dorsal diaphragms of animals in our porcine model, possibly because this is one of the most remote and least depen- dent areas of the pleural space in an upright quadriped. However, this explanation is only speculative. When insuffiating talc through a thoracoscope, we have found that talc distribution can be improved by manual ly lifting the collapsed lung to apply talc to the posterior aspects of the pleural space, including the posterior diaphragm. For TS, we used the technique of Webb and associates [2] of rotating the patient after instillation of the talc to improve distribution. Whether this is necessary is not proven. Some surgeons add iodide to the talc when performing pleurodesis because it is thought to cause a more effec- tive pleuritis; however, this also has not been proven. In fact, Singer and co-workers [10] found no difference in the pleural reaction to talc in rabbits with or without

1002 COHEN ET AI_ Ann Thorac Surg TAI,C PLEURODESIS: PORCINE MODEl 1996;62:1000-4

iodine. One interesting note regarding the use of iodized talc is that the iodine makes the talc visible on chest roentgenogram, which may aid in determining whether it has been distributed throughout the pleural space [2].

Serious toxicity with talc pleurodesis is unusual . Car- diovascular complications such as arrhythmias, cardiac arrest, myocardial infarction, and hypotension have been reported. However, their actual relation to the talc is difficult to ascertain [1]. Respiratory insufficiency, includ- ing adult respirator), distress syndrome, also has been reported with both TS and talc poudrage [11, 12]. The mechanism of respiratory insufficiency is unclear, but may be dose related [1]. Minor side effects of talc pleu- rodesis include pain, which is usually mild [13], and fever, which occurs 4 to 12 hours after talc instillation and may last for 2 to 3 days [1].

Considerable controversv exists regarding the most suitable technique for talc pleurodesis. Recently, video- assisted thoracoscopic surgery, with talc poudrage has become popular with many surgeons. Proposed advan- tages of this technique include the opportunity to explore the pleural space and to biopsy suspicious lesions if necessary, and the ability to take down adhesions and drain loculated areas of effusion. Furthermore, this tech- nique allows excellent distribution of a fine layer of insufflated talc under direct visualization. Disadvantages of video-assisted thoracoscopic surgery, for talc insuffla- tion are the frequent requirements of a general anes- thetic in the operating room and double- lumen endotra- cheal tube intubation. Morbidi~ T and mortality can be substantial in this group of often debilitated patients, as demonstrated by Ohri and colleagues [4], who reported a mortality rate of 5°,0 in patients who underwent thoraco- scopic talc poudrage under general anesthesia. The sin- gle death in our animal model was due to a pneumotho- rax, which a malfunctioning chest tube failed to evacuate.

In addition to the increased morbidity and mortality associated with general anesthesia and talc pleurodesis, the use of the operating room with its staff and expensive equ ipment (both disposable and reusable) may increase the cost of talc pleurodesis dramatically. In response to the increased morbidity and cost associated with TTI under general anesthesia, many practitioners have re- sorted to performing TTI under local anesthesia, using a simple 7- to 10-mm thoracoscope, with excellent results [14, 15].

Advantages of TS through a simple thoracostomy tube include its high success rate, safety, low cost, and sim- plicity. There is no need for expensive equipment , general anesthesia, or the operating room. If, as demon- strated in this study, comparable pleurodesis is obtain- able with this technique, it would seem to be the proce- dure of choice for most patients with chronic pleural effusions and for selected patients with pneumothorax. Exceptions would include patients who also require

thoracoscopy for other reasons, such as the need to make a diagnosis in the case of a pleural effusion or to stop an air leak in a patient with persistent or recurrent pneu- mothorax.

In summary, effective pleurodesis in a porcine model can be obtained with either TS through a thoracostomy tube or TTI. In light of the cost and morbidity of video- assisted thoracoscopic surgery when compared with a simple thoracostomy tube, TS may be the preferred clinical approach in patients with chronic pleural effu- sions and in selected patients with recurrent pneumotho- rax who do not require thoracoscopy for other reasons. This study emphasizes the need for a prospective clinical study comparing these techniques.

References

1. Kennedy L, Sahn SA. Talc pleurodesis for the treatment of pneumothorax and pleural effusion. Chest 1994;106:1215-22.

2. Webb WR, Ozmen V, Moulder PV, Shabahang B, Breaux J. Iodized talc pleurodesis for the treatment of pleural effu- sions. J Thorac Cardiovasc Surg 1992;103:881-6.

3. Daniel TM, Tribble CG, Rodgers BM. Thoracoscopy and talc poudrage for pneumothoraces and effusions. Ann Thorac Surg 1990;50:186-9.

4. Ohri SK, Oswal SK, Townsend ER, Fountain SW. Early and late outcome after diagnostic thoracoscopy and talc pleu- rodesis. Ann Thorac Surg 1992;53:1038-41.

5. Bethune N. Pleural poudrage: a new technic for the deliber- ate production of pleural adhesions as a preliminary to lobectomy. J Thorac Surg 1935;4:251-61.

6. Frankel A, Krasna l, Baronofsky ID. An experimental study of pleural symphysis. J Thorac Cardiovasc Surg 1961;42: 43-51.

7. Mathlouthi A, Chabehoub A, Labbene N, et al. Etude anato- mopathologique experimentale du talcage pleural. Rev Mal Respir 1992;9:617-21.

8. Bresticker MA, Oba J, LoCicero J, Greene R. Optimal pleu- rodesis: a comparison study. Ann Thorac Surg 1993;55:364-7.

9. Hartman DL, Gaither JM, Kesler KA, Mylet DM, Brown JW, Mathur PN. Comparison of insufflated talc under thoraco- scopic guidance with standard tetracycline and bleomycin pleurodesis for control of malignant pleural effusions. J Tho- rac Cardiovasc Surg 1993;105:743-7.

10. Singer JJ, Jones JC, Tragerman LJ, Sherman L. Aseptic pleuritis experimentally produced. J Thorac Surg 1941;10: 251- 83.

11. Rinaldo JE, Owens GR, Rogers RM. Adult respiratory dis- tress syndrome following intrapleural instillation of talc. J Thorac Cardiovasc Surg 1983;85:523-6.

12. Todd TRJ, Delarue NC, lives R, Pearson FG, Cooper JD. Talc poudrage for malignant pleural effusion [Abstract]. Chest 1980;78:542-3.

13. Walker-Renard P, Vaughn L, Sahn SA. Chemical pleurode- sis for the treatment of malignant pleural effusions. Ann Intern Med 1994;120:56-64.

14. Aelony Y, King R, Boutin C. Thoracoscopic talc poudrage pleurodesis for chronic recurrent pleural effusions. Ann lntern Med 1991;115:778-82.

15. Davidson AC, George RJ, Sheldon CD, Sinha G, Corrin B, Geddes DM. Thoracoscopy: assessment of a physician ser- vice and comparison of a flexible bronchoscope used as a thoracoscope with a rigid thoracoscope. Thorax 1988;43: 327-32.

Ann Thorac Surg COHEN ET AL 1003 1996;62:1000-4 TALC PLEURODESI$: PORCINE MODEL

DISCUSSION

DR JOSI~ RIBAS MILANE Z C A M P O S ($5o Paulo, Brazil): First of all, I congra tu la te Dr C o h e n for the pape r a n d his p r e sen t a - tion.

At the Univers i ty of $5o Paulo in Brazil, we have been u s ing 2 g of talc as an agen t to p r o m o t e p leurodes is , de l iver ing it t h r o u g h a thoracoscopic app roach s ince 1983, with effective resu l t s of 94.6%. We have u s e d this t e chn i que in m o r e t han 230 pa t ien ts with m a l i g n a n t p leura l effusion w h e n it is e s t ab l i shed tha t the lung will fully expand .

A few m o n t h s ago, we used this t e c h n i q u e in a b reas t cancer patient . Two days later, talc crystals were no ted in he r b ron- choalveolar lavage. Later on, this pa t ient died, and he r au topsy revea led talc embol i in p u l m o n a r y vesse ls and cerebral arteries.

C o n c e r n e d abou t this f inding, we wen t to the laboratory, and, work ing with a rat mode l u s i ng 0.002 g, we were able to detect a d h e s i o n s in the p leura l space and talc embol i in the contra la t - eral lung. We also found embol i of talc in the liver, spleen, kidney, and the bra in in a lmos t 100, , of the an i ma l s tha t were killed 48 to 96 hour s after the p leura l appl ica t ion of talc.

In our opinion, t hese i s sues about t a l c - - h o w to use it, the a m o u n t to be used , and the collateral effects it can c a u s e - - deserve m u c h more research.

DR COHEN: Doctor C ampos , t h a n k you verv m u c h for vour c o m m e n t s .

We did not specifically look for the p resence of talc in o ther organs , and we only saw it occasional ly in the lungs in the s tud ies tha t we did. I agree tha t mos t peop le ' s exper ience wou ld conf i rm tha t the s ide effects and toxicity f rom talc in the p leura l space are p robab ly dose related. W e had I pa t ien t who had wha t a p p e a r e d to be an anaphylac t ic reaction; we had u sed 10 g in tha t patient . We have u sed 5 g very safely, and it s e e m s tha t 5 g s e e m s to be the dose of choice a m o n g mos t su rgeons .

DR CAROLYN M. DRESLER (Phi ladelphia , PA): 1 f ound this pape r ve D' in te res t ing because of some ongo i ng trials looking at talc. A couple of th ings m a y be a p rob l em in work ing with i m m a t u r e pigs. The p rob l em in h u m a n s is m a l i g n a n t p leura l effusions. The issue that the cu r r en t trial is inves t iga t ing mal ig- nan t pleural effusions, and mos t s u r g e o n s th ink that video- ass i s ted thoracic su rge D' is p robab ly mos t useful because vuu can get a good c i rcumferent ia l look at the lung, you can break down the adhes ions , and you can create a r e e x p a n d e d lung. Lack of r eexpans ion and a d h e s i o n s would not have been a p rob l em with the i m m a t u r e pig. 1 noted in 1 of your pigs tha t you did have a p rob lem because of the posi t ion of the lung, so p e r h a p s this poin ts out a p rob l em in get t ing a good c i rcumfer- ential d is t r ibut ion of the talc.

O n e of the th ings you had said is that talc s lurry was p robab ly going to be better; however , w h e n vou looked at the 11 pigs, the pig that did the best was the one that had v ideo-ass i s t ed thoracic surgeD' . It was this pig that had the mos t dense adhes ions , ve r su s 1 o ther pig tha t had talc s lurry and that did not do as well. So I th ink the ques t ion is still u n a n s w e r e d about w h e t h e r talc s lurry or the v ideo-ass i s t ed thoracic surgery_ talc p rocedure is go ing to be best . No doub t the cost is going to be cons iderab ly different, bu t in the h u m a n pa t ien t with a m a l i g n a n t p leura l effusion, the a n s w e r is still u n k n o w n .

The ques t ion 1 wou ld like to a d d r e s s to the last d i s cus san t is w h e t h e r the use ot talc is still of concern to phys ic ians? As w)u impl ied, the dosage is not at all known. There are no good s tud ies explor ing appropr ia te dosages . Doctor Sahn, who is a

p u l m o n o l o g i s t a n d has looked at this i ssue of talc toxicity, defini tely has f o u n d talc part icles in mul t ip le o the r o rga n s in an imal models . I t h ink we n e e d to be a d d r e s s i n g this ques t i o n in h u m a n s .

This was an excel lent p resen ta t ion .

DR COHEN: I agree wi th Dr Dres le r tha t our s t udy was pe r fo rmed in y o u n g an ima l s with n o r m a l p leura l spaces . The reason is that the real ra t ionale for the s t udy was to see h o w well the two modal i t i es wou ld d is t r ibute the talc. I also agree tha t there are pa t ien ts w h o have locula ted or complex effus ions w h o are good cand ida te s for thoracoscopy, because you can take these down and get a bet ter p leurodes is . However , I also th ink that w h e n you put a ches t t ube in and get good l ung inflation, the major i ty of pa t ien ts are cand ida t e s for talc slurry. I t h ink you can get a s imilar resul t wi thou t hav ing to expose t h e m to the m o r b i d i t y of a gene ra l a n e s t h e t i c a n d tho racoscop ic talc poudrage . 1 m u s t say tha t we lea rned tha t l esson the ha rd way: We have seen s o m e subs tan t i a l morb id i ty and s o m e d e a t h s by not se lect ing our pa t i en t s well in t e rms of wh ich ones wi th m a l i g n a n t p leura l ef fus ions were go ing to tolerate genera l anes - thesia.

In regard to the fact that I pig had a be t ter resul t wi th one t e chn ique over the other, 1 th ink tha t it is ha rd to m a k e a s s u m p t i o n s ba sed on only 1 an imal . Eight of the 10 p igs had a lmos t identical resu l t s with both modes . I s u s p e c t tha t there was a del ivery p r o b l e m wi th the talc s lur ry in tha t an imal , t h o u g h we were not able to ascer ta in that for sure .

DR LEWIS WETSTE1N (Freehold, NJ): Doctor C a m p o s ' com- m e n t s are ex t remely d is t ress ing . Never the less , pu t t i ng t h e m as ide for a second, do you have any p re l imina ry clinical data? Do you use this t e chn ique for p n e u m o t h o r a c e s ? If you do, do you use the talc s lur ry for an initial p n e u m o t h o r a x , or do you use it onlv fur r ecu r r en t p n e u m o t h o r a c e s ?

D R COHEN: We are re luc tan t to use talc at all for pa t ien ts with ben ign disease. However , 1 th ink tha t the re is a g roup of pa t i en t s who are older and have chronic obs t ruc t ive p u l m o n a r y d i sease with r ecur ren t p n e u m o t h o r a c e s who are not cand ida t e s for t r ansp lan ta t ion bu t are cand ida te s for talc p leurodes is , wi th good resul ts .

DR WETSTEIN: If you do not use talc, do you use any o ther modal i tv for p n e u m o t h o r a x , or none at all?

DR COHEN: 1 du not u se a n y t h i n g o ther t han talc now, no.

DR JOSEPH LoCICERO IIl (Boston, MA): This was an excel lent paper . I th ink this area n e e d s a lot m o r e s tudy. I w a n t to caut ion people who are go ing to be u s ing talc slurD'. Maybe Dr C o h e n would wan t to c o m m e n t on his own clinical applicat ion. We have found that this is a s u s p e n s i o n in which the talc c o m e s out of solut ion ex t remelv fast. Because of this, the old t radi t ional t e c h n i q u e s of p lac ing tetracycline or doxycycl ine in the chest , c l a m p i n g the tube, and roll ing the pa t ien t a r o u n d for severa l hou r s really do not mat ter . So p lac ing it in t h r o u g h a smal l need le in the tube over a long per iod of t ime a n d a l lowing the pat ient to be at bed rest for a long t ime really is no t the appropr ia t e m e t h o d . We place the talc s lur D' in very, rapidly an d re lease the ches t tube immedia t e ly , because it is go ing to come out of s u s p e n s i o n r ight into the l ung immedia t e ly .

1004 COHEN ET At. Ann Thorac Surg TALC PLEURODES[S: PORCINE MODEL 1996;62:1000-4

DR COHEN: In our experimental model, we duplicated the technique that was described by Watts Webb in 1992 because of his excellent results, and I certainly agree that you have to make sure that the talc is in solution and that you give it and flush the talc quickly.

DR SEPPO E. RAPO (Hyannis, MA): Do you have any experi- ence with or any comments on the now experimentally available aerosolized talc?

DR COHEN: Our experience is limited. I have found that the jet on the commercial talc, because it comes through a very small tube, is difficult to distribute; you really have to paint the lung with it. In addition, the cost is many times more than just having your pharmacy sterilize 5 g of USP talc.

DR STEVEN M. SCHWARTZ (Campbell, CA): Your last com- ment brings up the question of how you go about sterilizing the talc. The only approved way that I know is dry_ heat sterilization, which is not widely available commercially. As far as I know, the only commercially sterile preparation of talc that is available is

the aerosolized can. I would like to hear your comments about how you prepare it.

DR COHEN: 1 believe our talc is heat sterilized. Early on, they were culturing it every few weeks to make sure that it was sterile, but sterility has not been a problem.

DR DRESLER: l was recently at the Food and Drug Adminis- tration's ODAC evaluation looking at the question of talc, because the Bryan Corporation, which makes the aerosolized talc, has been trying for the past year to get Food and Drug Administration approval. First of all, there is no approved method for sterilizing talc. There are three recommended meth- ods, for which I would refer you to a 1995 article in Chest (107:1032-4). Talc is readily available from a large number of chemical companies. The Bryan Corporation talc may or may not be approved in the future. There still is the question of toxicity, which must be answered. At present, however, it is the only talc commercially available as an investigational new drug with the Food and Drug Administration.

Internet Announcement The fo l lowing two ar t ic les will b e p u b l i s h e d in t he N o v e m b e r 1996 i s sue of The Annals of Thoracic Surgery, a n d h a v e b e e n s e l ec t ed for d i s c u s s i o n top ics on t he i n t e r n e t . T h e s e d i s c u s s i o n g r o u p s can b e a c c e s s e d by g o i n g to T h e Soc ie ty of Thorac i c S u r g e o n s H o m e Page ( h t t p / / w w w . s t s . o r g ) a n d c l i ck ing o n " D i s c u s s i o n Fo- r u m s . " W e e n c o u r a g e e v e r y o n e to pa r t i c ipa te , as ou r goal is to m a k e the d i s c u s s i o n as i n t e r ac t i ve as poss ib le .

Intermediate Resu l t s of the Extracardiac Fontan Proce- dure John C. Laschinger , MD, J. M a r k R e d m o n d , MD, Duke E. C a m e r o n , MD, Jean S. Kan, MD, a n d Richard E. Ringel, M D

Standard Criteria for an Acceptable Donor Heart Are Restricting Heart Transplantation V a l l u v a n J e e v a n a n d a r n , MD, Sa to sh i F u r u k a w a , MD,

T h o m a s W. P r e n d e r g a s t , MD, B a r b a r a A. Todd , CRNP,

H o w a r d J. Eisen, MD, a n d J a m e s B. M c C l u r k e n , M D

Tom Karl MD Internet Annals Editor Melbounle, Australia E-maih karl@cryptic.rch.unimelb.edu.au