Microsoft word - 0021-opinion _saeidi_.doc

Arch Iranian Med 2005; 9 (2): 173 – 174 HOW TO MANAGE ASYMPTOMATIC LIVER HYDATIDS
stage of the parasite Echinococcus granulosus in man.2 Mebendazole has been used for many years C countries. Only rarely now, and in India as an effective vermifuge with low primarily because of increased international travel, liver hydatids surface as clinical curiosities at accumulated to show that clinical efficacy of these medical conferences in western countries. The drugs against hydatid cyst is no more than about situation is usually that of a liver hydatid having 50%, even after prolonged administration. ruptured into the biliary system causing bile duct Fortunately their toxicity over long periods of time obstruction. Invariably the consensus among is also very low.3, 4 It would be reasonable, discussants is that the patient should have been therefore, to empirically administer these drugs to operated upon much earlier to avoid the cyst patients in endemic areas who are accidentally becoming complicated. Such a verdict, however, is found to have a benign cystic lesion of the liver inappropriate and inapplicable in endemic areas of suspected to be echinococcal. Drug treatment developing countries where echinococcal disease is should be continuous and not interrupted, with still rampant.1 In these regions so many cases of liver function and the blood picture checked at asymptomatic cases of liver hydatids are detected intervals, and pregnancy avoided in the interim. in the course of ultrasound investigation for other Both the physician and the patient should fully conditions, that it would impossible to handle all of understand that success is neither guaranteed nor apparent until at least a full year of drug treatment. The fact that many liver hydatids are first Involution of the cyst may have been the fate of the encountered as irrgularly calcified and clinically cyst and not the effect of the medicine. Given the silent lesions, suggests that most liver hydatids fact that pharmaceutical companies of industrial undergo a slow process of spontaneous abortion. countries are not likely to invest money in They can, therefore, be left alone. An equally discovering better drugs for Echinococcosis, a important reason for a conservative approach to disease seen only in endemic areas of the world, incidentally discovered liver hydatids in endemic one should not expect a truly effective drug for this parasitic condition becoming available soon. The asymptomatic liver hydatids prophylactically to problem of how and when asymptomatic liver avert possible complications, would overwhelm hydatids should be treated, remains unknown. available health resources in endemic areas. To Another approach to asymptomatic liver hydatids, operate on the many, fearing complications in the also originating in the West, is percutaneous needle few, cannot be justified in that setting. aspiration of the cyst followed by instillation of Can incidentally discovered asymptomatic liver hypertonic saline and 90% alcohol.5 For a number cysts be treated mediaclly when risk taking, even of reasons this particular form of treatment, while for the few, is unacceptable? About forty years ago in line with the now fashionable mode of minimal benzimidazole carbamate derivatives, mebendazole access cannot be recommended, for two reasons: first and then albendazole, were reported from a) While univesicular liver cysts can be needle Europe to have deleterious effects on the larval aspirated, only centrally located multivesicular hydatids are likely to rupture into major bile ducts Author’s affiliation: Academy of Medical Sciences of I.R. Iran.
and precipitate acute biliary obstruction. Hitting each and every small daughter cyst in these •Corresponding author and reprints: Farokh Saidi MD,
Academy of Medical Sciences of I.R. Iran. Fax: +98-21-22938051
multivesiular lesions is technically impossible and Accepted for Publication: 25 January 2005 Archives of Iranian Medicine, Volume 9, Number 2, April 2006 173 How to mange asymptomatic liver hydatids to a complication. For unknown reasons, some cyst b) Notwithstanding many reports of presumed may stop growing at any time while some cysts success, 20% hypertonic saline does not have the reach an enormous size and remain clinically hoped for scolicidal potency, nor is it innocuous.6 silent. Still, if serial songraphic studies at, say, six Lastly, entry of these agents into the biliary tree is monthly intervals show definite enlargement of a likely to result in lethal sclerosing cholangitis particular cyst, that particular cyst bears watching The aim in this compact overview of treating incidentally discovered liver cysts are likely to asymptomatic liver hydatids has been to declare become complicated, justifying their prophylactic those management policies originating or applied treatment. The natural course of the disease, in in industrial West, where the disease no longer particular the relative frequency of a given cyst exists, as not necessarily applicable or appropriate becoming calcified is not known. Clearly, the to endemic East, where the disease still abounds. needed information will not become available if a However, one treatment policy that emanated in preemptive surgical intervention to avoid the risks the industrial West more than a century and a half of complication, no matter how remote, is the ago, should be put into action in all parts of the dominant treatment policy. The fact that hydatid world endemic to echinococcal disease, as it broke cysts grow at a very leisurely pace makes it the life cycle of the parasite: rigid enforcement of difficult to convince patients with asymptomatic public health measures, to prevent access of stray cysts to wait for months if not years to see if they dogs to offal at slaughterhouses. That this self- are or are not at risk. It is true that in the end either evident step has not been followed or perhaps the host or parasite must die. But the odds are cannot be followed in endemic areas of the world, heavily stacked against the latter, even though liver underlines one particular aspect of this parasitic cysts take a long time before showing which way condition: the effective control of this disease as well as the public health problems it creates, is economically justifiable approach to the large number of incidentally discovered asymptomatic References
liver hydatids encountered in endemic areas? For one thing, vague pain and nonspecific complaints Eckert J, Schantz P, Gasser R, et al. Geographic localized to the upper abdomen, usually noticed by distribution and prevalence. In: Eckert J, Gemmell MA, patients when their liver cyst has been discovered, Meslin FX, Pawlowski ZS, eds. WHO/OIE Manual on Echinococcosis in Humans and Animals: a Public Health can be safely ignored. There is no anatomic or Problem of Global Concern. Paris: World Organization pathologic reason for an uncomplicated liver for Animal Health: World Health Organization; 2001: hydatid cyst to be symptomatic, regardless of its size or location. They expand much too slowly to Horton R. Albendazole in treatment of human be able to stretch Glisson’s capsule. It might be echinococcosis: 12 year experience. Acta Trap. 1997; 64:
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difficult to assure patients that their vague aches Liu Y. Continuous or intermittent treatment with and pains do not portend imminent rupture into Albendazole? Arch Int Hidatid. 1997; 32: 171 – 173
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been well summarized.7, 8 My personal opinion is Filice C, Brunetti E. Use of PAIR in human cystic that a positive serology can be dismissed as useless echinococcosis. Acta Trop. 1997; 64: 95 – 107.
in terms of indicating viability and hence the Kayaalp C, Balkan M, Aydin C, et al. Hypertonic saline in hydatid disease. World J Surg. 2001; 25: 975 – 979.
There can be no question, of course, that a liver MacManus DP, Wenbao ZH, Fun L, Bartley PB.
Echinococcosis. Seminar. Lancet. 2003; 362:
hydatid must be viable and grow in size to impinge and cause pressure necrosis of the wall of an Rickard M, Lightowlers M. Immunodiagnosis of hydatid adjacent large bile duct to bring about a serious disease. In: Thompson R, ed. The Biology and complication. This does not mean, however, that Echinococcus and Hydatid Disease. London: George Allen and Unwin; 1968: 217 – 249. expansion in size is relentless, nor inevitably lead 174 Archives of Iranian Medicine, Volume 9, Number 2, April 2006

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