biopsy makes it possible to obtain a histological diag­nosis in 90% of the cases, which may be particularlyuseful for the detection of malignant lesions whenEUS findings are not significant.

The authors describe the use of a new biopsy needle with aguillotine device that makes it possible to obtain histologicalspecimens of gastric submucosal tumors. This type of needleis derived from those that have been used successfully forsome time in echo-guided biopsies of the prostate and variousabdominal organs (especially the liver). The method seems tobe particularly suitable for differentiating leiomyoma fromleiomyosarcoma in cases in which, as frequently occurs, di­agnosis with endosonography alone is not possible.

The survey is not, however, large enough to establish withcertainty whether this type of needle can give better resultsthan fine needle aspiration biopsy with cytology needles. Goodresults were previously obtained with the latter in infiltrativetumors of the gastrointestinal tract, but not in completelysubmucosal lesions (Gastrointest Endosc 1988;34:321-3;1989,35:207-9). More recently, in a prospective study of 265consecutive cases of malignancy of the esophagus, stomach,colon, and rectum, aspiration cytology gave the highest diag­nostic accuracy (94%), significantly better than that of biopsyand brush cytology. The results were significantly better insubmucosal tumors. Benign submucosal lesions were alsocorrectly identified by endoscopic fine needle aspiration (Gut1991;32:745-8).

A similar study to that of Caletti et al. has been publishedin this Journal involving the combined use of EUS and fineneedle aspiration biopsy, showing good results in the evalua­tion of extrinsic, submucosal, and ulcerative lesions of thegastrointestinal tract (Gastrointest Endosc 1992;38:35-9).

Recently, a successful puncture of the pancreas was alsoperformed guided by endoscopic ultrasonography with aneedle introduced through a channel of the echo-endoscope(Gastrointest Endosc 1992;38:170-1, 172-3). This lattermethod performed with a curved array ultrasonic transducerwith a longitudinal scanning plane is certainly able to offerthe best results, making a precise guiding of the needle possibleat the level of the lesion from which the biopsy is to be made.

Up until now most research has been carried out withcytology aspiration needles. Guillotine needles, which mightoffer the advantage of providing fragments for microhistology,do however require further testing as they are more likely tocause hemorrhages or, with a perpendicular needle approach,even perforations. With this type of needle, it is also moredifficult to perform transparietal biopsies of lesions outsidethe digestive tract, while they can be made with cytologyneedles.

LIONELLO GANDOLFI

Bologna, Italy

Transrectal ultrasonography in Crohn'sdisease

VAN OUTRYVE MJ, PELCKMANS P A, MICHIELSEN PP,

VAN MAERCKE YM

Gastroenterology 1991;101:1171-7The authors studied 40 healthy individuals and 40consecutive patients with Crohn's disease by means

VOLUME 38, NO.6, 1992

of transrectal ultrasonography (TRU). A rigid linearendorectal probe with a frequency of 5 MHz was usedto examine the rectal wall, the perirectal tissues, andthe anal sphincter. The five rectal wall layers couldbe clearly seen in the healthy subjects and wall thick­ness was less than 4 mm. An increase in the rectalwall thickness was observed in 40% of all patientswith Crohn's disease and in 58% of those with activeproctologic lesions.

TRU also revealed almost twice as many para-rectaland para-anal abscesses as previous proctoscopy andproctography.

TRU was shown to be superior to CT scan for thediagnosis of para-anal abscesses and fistulas. In allpatients with a para-anal fistula, the fistulous tractwas revealed by TRU. The morphology and dimen­sions of the anal sphincter were evaluated. In normalsubjects, the anal sphincter was visualized as an echo­poor and sharply delineated structure. In Crohn'sdisease a marked heterogenicity of the anal sphincterwas seen in 47% of cases. In all of the subjects exam­ined, the anal sphincter increased in breadth duringsqueezing and in length during straining. Thesechanges however were less pronounced in the patientswith active proctologic Crohn's disease.

The role of TRU in the diagnosis and staging of rectal tumorshas been clearly established for some time. Few studies, how­ever, have attempted to assess the usefulness of this methodin inflammatory diseases and in Crohn's disease in particular.The study made by Van Outryve et al. is a valid contributionin observing the prevalence of anorectal lesions in unselectedsubjects with Crohn's disease. In agreement with other au­thors (Gastrointest Endosc 1990;36:331) the lesions found arean enlargement of the rectal wall as well as complicationssuch as para-rectal and para-anal abscesses and fistulas. TR Udisclosed almost twice as many abscesses as with proctosig­moidoscopy and proctography.

The method appears to be preferable to CT due to the lowercost and easy performance as well as the improved images ofthe anal lesions, not always easy to examine with CT. Theseadvantages are particularly evident in the follow-up of theabscesses and fistulas. The possibility of performing echo­guided drainage of the abscesses should also not be neglected.

TRU was seen to be superior to fistulography, especiallyfor tortuous lesions, by Tio et al. (Gastrointest Endosc1990;36:331-6) who emphasized the advantages of the lowrisk of bacterial dissemination and low incidence of patientdiscomfort.

Another clear advantage is the detection of damage to thepelvic floor muscles or sphincters.

However, not all authors are convinced of the usefulness ofanal endosonography. Choen et al. (Br J Surg 1991;78:445­7) did not find any statistical difference between anal endo­sonography and digital examination in identifying inter- andtranssphincteric tracks. Moreover, ultrasonography would beunable to detect primary superficial, extrasphincteric, andsuprasphincteric tracks or secondary supraelevator and in­fraelevator extensions, including ischiorectal tracks.

One very interesting aspect in the article by Van Outryveet al. is the dynamic study of the anal sphincter during

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squeezing and straining. In active proctologic Crohn's diseasethese dynamic changes of the anal sphincter were less pro­nounced than in normal subjects. This study could be usefulin predicting and diagnosing anal incontinence.

LIONELLO GANDOLFI

Bologna, Italy

A prospective study of esophageal squamouscell carcinoma in achalasia

MEIJSSEN MA, TILANUS HW, VAN BLANKENSTEIN M,

ETAL.

Gut 1992;33:155-8The authors of this article from The Netherlands setout to establish the true incidence of esophageal car­cinoma in patients with achalasia and the efficacy ofendoscopic surveillance. One hundred and ninety-fiveconsecutive patients (90 men and 105 women) diag­nosed with achalasia between 1973 and 1988 werefollowed prospectively. The diagnosis of achalasia wasconfirmed by contrast radiology, endoscopy, andesophageal manometry. All patients underwent serialpneumatic dilation with review at 3 months and years1, 2, 4, 7, and 10 (or greater). Follow-up included abarium swallow, esophageal manometry, and EGDwith biopsy. If esophageal carcinoma was detected,staging was carried out. The incidence of squamouscell carcinoma (SeC) of the esophagus in the studygroup was compared with the expected incidence inage- and sex-matched controls, using the subject-yearsmethod. Follow-up after pneumatic dilation totaled874 person years. The mean age at the time of diag­nosis of achalasia was 52 years. Twenty-seven patientsdied over the course of the study, one from stage IVsec of the esophagus. This patient refused routineexaminations after 1 year; carcinoma was identified 3years later. Two of the remaining patients developedsec of the esophagus (stage I and IIa, respectively),resulting in an incidence of 3/874 person years or 3,4/1000 patients per year. The mean age at the time ofdiagnosis of squamous cell carcinoma was 68 years(range, 37 to 89 years). A mean of 17 years separatedthe onset of dysphagia and the diagnosis of carcinoma.The mean interval between the diagnosis of achalasia(as distinct from the onset of symptoms) and detectionof esophageal carcinoma was 5.7 years (range, 4 to 8years). Tumor was located in the middle third of theesophagus in all three patients, although it extendedto the distal esophagus in one. The expected incidenceof sec of the esophagus in an age- and sex-matchedpopulation in the Netherlands was 0.104/1000 pa­tients per year, resulting in a relative risk for devel­opment of squamous cell carcinoma of the esophagusin patients with achalasia of 33 (p < 0.001). Based onthese findings, the authors conclude that there issubstantially increased risk for the development ofesophageal carcinoma in patients with long-standing

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achalasia and recommend endoscopic screening every2 to 3 years. However, the authors also caution thattheir conclusions are based on data from only threepatients who developed cancer and suggest that large­scale studies are needed to accurately determine theefficacy and optimal frequency of endoscopic screen­ing in patients with achalasia.

'This article represents a commendable effort to identify thetrue incidence of malignancy complicating achalasia of theesophagus. However, some questions and problems arise.First, the authors fail to state whether or not the study andcontrol populations were screened for potentially confoundingvariables, such as cigarette smoking and alcohol use. Second,the incidence of esophageal malignancy in the control groupcould have been underestimated as these patients were sub­jected to less vigorous screening than the study population.Third, were biopsies directed at mucosal abnormalities only,or were random biopsies obtained? Of the 195 achalasia studypatients, did the 192 who reportedly did not develop malig­nancy have random biopsies during surveillance endoscopy?Finally, why were patients subjected to serial contrast radiol­ogy and esophageal manometry when the study was designedto establish the efficacy of endoscopic surveillance for malig­nancy in achalasia?

This study appears to demonstrate an increased incidenceof SCC of the esophagus in patients with long-standing ach­alasia over that of the general population of The Netherlands.The relative risk of 33 is impressive and appears to justifyselective screening for this high risk group. Three questionsare relevant to screening for any disease. First, does earlydetection improve survival? As cited in the excellent 1984review article by Lightdale and Winawer (Semin Oncol1984;11:101-12), large-scale studies of esophageal cancer inChina (Endoscopy 1982;14:157-61) suggest that early detec­tion may indeed improve survival. Using cytology obtained byblind abrasive balloon technique and subsequent endoscopicbiopsy, the accuracy of esophageal cancer detection in asymp­tomatic individuals in a high incidence province of China wasestimated as 80%, although the denominator is unclear. Ofparticular interest, 75% of the cancers detected were "early"lesions. Second, how severe is the disease itself? The 5-yearsurvival of patients with symptomatic esophageal carcinomahas been estimated at 10%. The cure rate following surgeryin early carcinoma patients in the Chinese study was report­edly 90%, a remarkable improvement suggesting that earlydetection of this disease benefits survival. The apparent longlead time adds weight to the case for screening. The Chinesestudy suggests that cytology can detect early, non-, or mini­mally invasive esophageal carcinoma and that the biologicrate of progression of these tumors is slow, in the order of 3to 4 years from localized to advanced disease. This wouldsuggest, as in the study from The Netherlands, that periodicscreening with intervals of 1 to 2 years will allow detection ofmost esophageal carcinomas at an early, potentially curablestage.

Finally, how good is the screening test itself? Endoscopywith brush cytology and biopsy has the highest sensitivity andspecificity of all of the available screening tests for esophagealcancer, although blind abrasive cytology may be comparablefor early carcinomas. However, endoscopy is preferable forscreening as positive blind cytology still necessitates endo-

GASTROINTESTINAL ENDOSCOPY