688 The Annals of Thoracic Surgery Vol 43 No 6 June 1987

Used in conjunction with pulsion intubation, laparoscopy can spare the patient with metastases a laparotomy; this was achieved in 68% of our patients.

C . D . lohnson, M.Chir., F . R.C.S.

Academic Surgical Unit St. Stephen's Hospital Fulham Rd London SWlO 9TH, England

References 1. Shandall A, Johnson C: Laparoscopy or scanning in

oesophageal and gastric carcinoma? Br J Surg 72:449, 1985 2. Cuschieri A: Value of laparoscopy in hepatobiliary disease.

Br J Surg 57:33, 1975 3. Vilardell F, Martivincente A: Peritoneoscopy (laparoscopy).

In Brockus HL (ed): Gastroenterology (vol4). Philadelphia, Saunders, 1976, pp 65-82

Reply To the Editor:

Dr. Johnson correctly emphasizes the importance of consider- ing laparoscopy in the evaluation of patients with cancer of the esophagus. I have also found this modality to be useful in stag- ing patients. He describes a prospective study of 50 patients in whom the diagnosis of metastases was obtained accurately in 96% by laparoscopy. Laparoscopy was compared with CT, but it is not possible from the data to determine the relative ac- curacies of CT, ultrasound, and laparoscopy in the group of patients with cancer of the esophagus. Of the 50 patients, 13 had the diagnosis of metastases made only by laparoscopy. However, this indicates that metastases were detected noninva- sively in 74% of the patients. Thus, rather than use laparoscopy routinely on all patients, one could argue that it should be used selectively as a confirmatory test in patients with metastases demonstrated on other noninvasive studies or in those patients that have an otherwise negative staging evaluation. The yield of laparoscopy will also be influenced by the location and histol- ogy of the tumor. This information is not available from their study. Laparoscopy may be a useful staging modality, but I feel that further prospective studies are needed to determine its hue value.

lack A . Roth, M . D .

Department of Thoracic Surgey M . D . Anderson Hospital 1515 Holcombe Blvd Houston, TX 77030

Easier Chest Tube Insertion To the Editor:

Dr. Ring is to be Congratulated on publishing the article entitled "Easier Chest Tube Insertion" (Ann Thorac Surg 41:583, 1986) based on his experience with 30 patients. For the past 20 years in hundreds of patients I have placed a large, curved clamp at the end of regular plastic chest tubes and prepared the tip with a knife blade in a manner identical to that described in his report; there have been no complications. The secret is to make sure the tip of the tube is not too pointed, so as to avoid a sharp

edge that potentially could stick into the lung. It is an excellent technique and cames no morbidity. It is much easier to perform than is inserting the blunt, round edge of the conventional chest tube.

The only question I had on reading his article was "Why didn't I publish this technique 20 years ago?'

Dr. Ring is to be congratulated on taking a few minutes of his time-to put the technique in writing and submit it for publica- tion-to share this technique with the readers of the journal.

Lowell L. Davis, M . D .

Thoracic and Cardiovascular Surgey 4316 Marina City Dr, G 308 CTN Marina Del Rey, C A 90292

Embolization of Calcific Material from Degenerated Bioprostheses To the Editor:

In the July 1986 issue of The Annals, Johnson and Gonzalez- Lavin [l] reported on a patient who died of myocardial infarc- tion caused by coronary artery embolization of calcific material from a degenerated Ionescu-Shiley aortic xenograft.

Our group recently raised the problem of systemic emboliza- tion of calcific cusp material in recipients of biological prosthe- ses. In fact, in 1982 we (21 reported on a patient who underwent reoperation for primary tissue failure of a mitral porcine bio- prosthesis, resulting from severe tissue calcification. Gross ex- amination of the explant revealed that a fragment of calcific tissue was loosely attached to the rest of the cusp, indicating an impending embolization of that material. Based on these findings we suggested that some of the major and minor throm- boembolic episodes observed in the late postoperative period in patients with porcine bioprostheses might be related more to the detachment of cusp fragments than to valve thrombogenic- ity. In fact, extensive lack of cusp substance in severely calcified bioprostheses is a common finding at reoperation [3], indicating that a washout of degenerated tissue has occurred and that calcific embolization probably is not so unusual, even though it fortunately is rarely associated with catastrophic sequelae.

Johnson and Gonzalez-Lavin [l] have reported an extremely interesting case, that should be kept in mind by all those in- volved in the postoperative follow-up of biological valve recipi- ents. Their and our observations clearly stress the need for early replacement of a failing xenograft, to avoid fatal complications such as the one described in their article.

Uberto Bortolotti, M . D . Aldo Milano, M . D . Alessandro Mazzucco, M . D .

lstituto di Chirurgia Cardiovascolare Universitd di Padova Via Giustiniani, 2 35128 Padova, ltaly

References 1. Johnson D, Gonzalez-Lavin L: Myocardial infarction second-

ary to calcific embolization: an unusual complication of bio- prosthetic valve degeneration. Ann Thorac Surg 42:102,1986

2. Bortolotti U, Milano A, Thiene G, et al: Evidence of impend- ing embolization of a calcific cusp fragment from a mitral porcine xenograft. Thorac Cardiovasc Surg 30405, 1982