CORRESPONDENCE/BOOK REVIEWS 841

BOWEL PREPARATION

SIR--We read with interest the comprehensive review of bowel pre- paration by Bartram [1]. This article is clearly based around the use of bowel preparation for contrast imaging of the gastrointestinal tract, although this is not specifically stated.

Bartram states that Klean Prep (Norgine, UK), a polyethylene glycol-based electrolyte solution, is contraindicated radiologically as 'retained fluid will destroy any chance of good double-contrast coating'.

Although we accept this view for barium enema preparation, we have found Klean Prep to be extremely useful for preparing patients prior to aorto-iliac colour flow Duplex ultrasonographic examination. We have presented figures showing that the use of Klean Prep increases the visualization of the iliac arteries over starving alone and that it also increases the number of stenoses diagnosed by this technique.

In the case of ultrasonographic examination the retained fluid within the bowel lumen is an advantage as it allows the transmission of ultrasound, giving clear views of the iliac vessels. In this situation gas obscures the very structures we are attempting to visualize.

Thus within the subject of the principles and practice of bowel preparation, we would recommend the use of Klean Prep to radio- logists using ultrasonography to investigate the aorto-iliac vessels, or related structures.

M. S. WHITELEY University Department of Surgery A. D. FOX Royal United Hospital Trust M. HORROCKS Coombe Park

Bath BA1 3NG

Reference

1 Bartram CI. Review: Bowel preparation-principles and practice. Clinical Radiology 1994;49:365-367.

STRECKER ESOPHAGEAL STENT

SiR -- I was interested to read the recent article by Dr Grundy describing the use of the Strecker Esophageal stent in the management of oesophageal strictures [I]. I would agree that the use of these stents in the management of benign oesophageal strictures needs to be fully evaluated. I have used a self-expanding Strecker stent in a 98-year-old lady who was requiring repeated endoscopic dilatations for the management of a benign oesophageal stricture (Fig. 1). She has been followed up for 6 months following the procedure and has had no further problems with dysphagia. She is on long-term maintenance Omeprazole therapy. The latter medication is likely to prevent the problem of recurrent stenoses at the edges of the stent. The combined use of self-expandable stent together with maintenance Omeprazole

Fig. 1 - Omnipaque swallow demonstrating a self-expandable stent across stricture.

therapy may be a useful form of management in elderly patients with benign oesophageal strictures.

D. R. FOSTER

Reference

Prince of Wales Hospital Coity Road

Bridgend Mid Glamorgan CF31 1RQ

1 Grundy A. Clinics in interventional radiology- The Strecker eso- phageal stent in management of oesophageal strictures: technique of insertion and early clinical experience. Clinical Radiology 1994; 49:421-424.

Book Reviews

Medical Statistics: A Commonsense Approach, 2nd Edition. By M. J. Campbell and D. Machin. John Wiley & Sons, Chichester, 1993. 189 pp. s

Altman, in a recent editorial (British Medical Journal 1994;308:283- 284), expressed the view that many articles published in medical journals were based on unethical research, because the methods and statistical analysis were unsound. If reputable journals publish articles with statistical confusion and even clear-cut errors, little wonder that readers of such articles are in a constant state of confusion. It is my impression that most radiologists, including this reviewer, have a pretty poor knowledge of medical statistics. Doctors in general, and radiolo- gists in particular, have an earnest desire to learn the necessary facts and logic underpinning their own disciplines. Why then do so few master the essential tools of medical statistics? The reasons must lie in the educational process. As so often in medicine there is an emphasis on detail, such as how to do specific calculations, rather than on the

principles behind the statistical tests, e.g. what they demonstrate, their limitations, the type of test needed for particular situations, etc.

This book is a clever attempt to provide the appropriate background for those who wish to understand medical statistics. It is specifically intended for medical students and nurses, but is designed to provide qualified doctors with the essentials of statistical design and interpretation. Campbell and Mackin avoid becoming bogged down in detail, but cover in outline form many of the statistical methods in common use in medical articles. The emphasis is on study design and which tests to use, rather than on details of how to perform calculations; the authors assume that most investigators will need to call on a statistician for specialist advice.

Most books in statistics are very difficult to read, but this one is an exception; it does not lose sight of the fact that its audience is likely to consist largely of critical readers of medical journals and individuals taking their first steps in research. It is, therefore, highly recommended.

Peter Armstrong