Laminaria digitata: A Checkered Career BARBARA RUBIN t

Removal of most legal sanctions in the United States against termination of pregnancy has contributed to the recent rediscovery of the vegetable "tent" method for cervical dilatation. 2 One effect of this rediscovery has been the revival of a specialized seaweed industry which flourished in Europe more than a century ago. Gynecological practitioners in the mid19th century had sought to obtain cervical dilation through experimentation with a variety of organic materials, "so as to get access to the interior of the uterus for diagnostic and therapeutic purposes" (35). Dried gentian root, bark of the slippery elm, corn stalks, and pieces of sponge were all used, the last by dipping the sponge in a gum solution and compressing it into a conical form by whip-cording (35, 36). Such experimentation was confined neither to the western world nor to the medical profession per se. Schneider (34) observed an apparently old tradition of self-induced abortion on the island of Yap in the South Pacific, in which a thin-rolled plug of dried hibiscus leaves was introduced into the cervical passage. T h e m o u t h of the cervix was then injured or scratched t Department of Geography, University of California at Los Angeles. Submitted for publication September 8, 1974; accepted for publication May 14, 1975. T e n t (L. tenta, from tendere, to stretch). 2. A conical and expansible plug of soft material as lint, gauze, etc., for dilating an orifice or for keeping a wound open, so as to prevent its healing except at the bottom, laminaria t., a tent made of sea tangle or laminaria, sponge t., a slender coneshaped piece of compressed sponge: used for dilating the os uteri 9 tupelo t., one made of the wood of the root of the water-tupelo, a tree (Nyssa uniflora) of North America. (Dorland's Illustrated Medical Dictionary, 24th ed., London, Phila., 1965)

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until blood was drawn, a procedure which apparently served to hasten the expansion of the plug through the absorption of local fluids. MEDICAL HISTORY

T h e use of the brown algae Laminaria digitata (L.) Edmonson as an efficacious dilating agent was first published in Scotland in 1863. Sloan (37) in a report based on the experimental results obtained with the use of L. digitata tents, observed that the property of diminishing bulk possessed by the Laminaria stipe when drying out had long been p u t to use by the western Celts in forming knife handles: the end usually fitted into the haft being inserted into a portion of the recent stem, is firmly grasped by the contraction that takes place in drying, while the soft and comparatively fragile material assumes the appearance, and almost the consistence, of buckshorn. I have found this a most convenient method of mounting a lancet . . . . 9

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.

Utilizing the property of diminished bulk in the dried Laminaria stipe, Sloan and some physician friends had found Laminaria to work well as a tent, owing to the fact that in a dried state the stipes retained "for years the power of readily absorbing moisture, and in a few days resuming almost their original size." As a tent, Laminaria absorbed the moisture from the cervix; the stipe was believed to double in diameter in four hours, and increased one and one half times more in diameter in forty-eight hours (37). In contrast, a tent of gentian root was observed to increase in diameter only by one third in the same time. Lamlnaria was also considerably cheaper than the popularly used sponge--

ECONOMIC BOTANY $1: 66-71. January-March, 1977.

three pence as compared to three shillings for sponge, or free to those physicians who accepted Sloan's advice and supplied themselves from the sea-shore. By 1869, Hicks (18) reported: "Of all the materials used for dilating the cervix uteri, there are none so cleanly efficient, and convenient as those made from Laminaria digitata.'" In the latter part of the 19th century, tents of Laminaria became widely used in France, Germany, Scandinavia and the British Isles. There are also reports of its gynecological use in Japan (28), where commercial exploitation of the brown algae or "kelp" for other purposes had been reported as early as 1670 (40).a PHYTOGEOGRAPHY

The brown algae or "kelp" are widely distributed, though species distribution is discontinuous. Although the Laminariacea are found in the Arctic Ocean, and in the northern Atlantic and Pacific basins, L. digitata appears confined primarily to the Atlantic basin with extensions into the Murman, Kara and White Seas. Its Pacific counterpart, Laminaria japonica Aresch., is widely distributed in the Sea of Japan, the Gulf of Tartary, and in Olga and Transfiguration Bays (8, 39). In the early literature, it was frequently referred to as "oarweed," "castweed," or "tangle." In an early study of the phytogeography of the Faeroese coasts, Borgensen (3) found L. digitata to grow primarily along open coasts, and he found the plant to be well adapted to resist the violence of the waves. According to Chapman (8) L. digitata grows from the low water mark down to about two or three fathoms, where it becomes replaced by a related species. L. digitata cannot survive exposure for any extended period of time, and for sexual reproduction the species requires fairly cold water temperatures, thus confining its range and distribution to the more frigid waters of the oceans. Great quantities of L. digitata have been observed to be reguIn Europe, "kelp" originally referred to burnt ash derived from seaweed; this 17th century processing of seaweed obtained iodine, iodides and potassium salts. Kelp is now a generalized term referring simply to seaweed (8, 38).

L A M I N A R I A DIGIT.4 TA

larly cast up on the shores of Western Ire/and and Scotland. In Japan and China, however, kelp is cultivated through specialized techniques in marine "farming," because the wild sources of Laminaria have proved to be insufficient for commercial needs (8, 9). EXPLOITATION AND REJECTION

Although many species of brown algae have been harvested for various commercial purposes, both L. digitata and L. japonica were discovered to possess properties requisite for surgical uses. Though the plants are somewhat different morphologically, 19th century European and Japanese gynecologists appear to have noted independently the value of the Laminaria stipe as an aid in cervical dilatation. In Europe in the latter half of the 19th century, tent manufacture became primarily a German industry. Sinclair (36) observed somewhat chauvinistically in the Caledonian Medical Journal that the discovery of Laminaria for tent use had in fact originated with a Scottish physician. In what appears to have been a medical cause celebre to promote its "home" manufacture, he enjoined the benevolent interest of the Duke of Argyll in sponsoring a tent industry on the island of Iona. Tents made of L. digitata were noticeably in vogue for at least two decades, until evidence began to accumulate that suggested that morbidity with its use was as great as with that of other methods (l, 5, 24). In an era prior to Lister's discoveries, sepsis frequently occurred; Simpson (35) in 1864 had suggested that "if we wanted to be very economical, the same tent might be used a second time after simply being dried." Recent evidence reported in Newton (31) suggests that marine bacteria are relatively nonpathogenic for humans; the early assumption that Laminaria tents caused infection omitted from consideration other clinical variables such as re-use as suggested by Simpson. In addition to problems of infection associated with the use of Larninaria tents, the medical profession in the late 19th century was becoming increasingly fascinated with mechanical devices. Reviewing

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the rush to abandon Laminaria tents in favor of steel dilating instruments, Sinclair ($6) wrote: It was on the basis of pleading for timesaving machinery, without the knowledge and without the imagination to grasp the ruinous consequences of haste and force, that the gentlest, safest, and most efficient methods of dilatation ever invented were rejected in the United States; and the atrocious practices of the present time came into fashion. Defection in England was also typical of "the usual contingent of English gynaecologists who follow the newest foreign fashion." Laminaria tents were not abandoned in Europe however, due in part to their acceptance in France and Germany in the era of antiseptics. Sinclair (36) attempted in 1907 to promote the 20th century use of Laminaria tents by publishing directions for making aseptic tents for the convenience of physicians inclined to go to the seashore and gather their own raw materials. He suggested that the stipes be selected for the size of their diameters, and that the tents be shaped while fresh out of the sea, perforating as required for the attachment of a loop of silk thread to facilitate removal after use. After dessication, the stipes were to be sterilized by placing them in a solution of perchloride of mercury until the stem recovered its original size by saturation. Another drying, and then polishing to remove any surface roughness that might injure the cervical canal, rendered the tent suitable for use. Use of Laminaria tents in gynecological procedures has persisted in Europe and in Japan since the 19th century (13, 27, 28). In the United States, however, a brief summary of the disadvantages associated with Laminaria tents---essentially products of the 19th century circumstances of their use--was published in 1928 in a medical textbook by an eminent physician, Dr. H. A. Kelly (23). Although Kelley noted that accessibility of the uterine cavity obtained by means of tents was still superior to then-standard methods (steel dilators), he implied at the same time that the tent

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method was somewhat old-fashioned. This notice effectively eliminated the use of seaweed as a clinical adjunct in the United States for almost half a century--a triumph of technological vanity over clinical evidence. CONTEMPORARY REVIVAL T h e revival of interest in Laminaria tents for gynecological procedures and their commercial preparation in the United States now occurs more than a century after the algae was first suggested for such purposes. Legislative redefinition of acceptable criteria for termination of pregnancy began to emerge in various parts of the United States in the early 1970's, and gynecologists confronted daily with cervical obstruction to the performance of the nowlegal operation became increasingly interested in finding a new solution to a very old problem. Heretofore the problem of uterine access had not been acute; cervical dilatation for the purpose of curettage was usually carried out under general anesthesia and under circumstances quite different from those generated by the increased demand for abortion which physicians faced in the early 1970's. Discussion of abortion techniques was a topic generally avoided in medical texts and scholarly journals. Pommerenke (33), however, had published an article on abortion in J a p a n - - a country in which abortion had become legal at the end of World W a r II (30). In his 1955 article, Pommerenke tacitly acknowledged that abortions were indeed being performed in the United States, and for exhorbitant fees. American women, he stated, could visit Japan, "have an abortion done, and then return home happy, all at a cost below that often charged for the abortion alone in such cities as New York or Chicago." In 1955 the air fare to Japan was $966 and the cost of the operation was $5. 4 Pommerenke noted in passing that Lower fees and a heightened professional concern with abortion methods now reflect the changed legal status of abortion in the United States. The fee structure nevertheless still betrays an ambivalent attitude toward the operation. An informal survey in the Los Angeles area (1972-3)

ECONOMIC BOTANY

Laminaria tents were being used in Japan

for dilation prior to abortion. With the legalization of abortion in the United States, American physicians sought to use the latest and most advanced tools and techniques. Looking to Europe and Japan, where sanctions against abortion had earlier been lifted, they rediscovered - - a n d brought back to the United States-the Laminaria tents, which had been rejected by American physicians some fifty years earlier (15, 31). Contemporary American experimentation with Laminaria tents prove them to be reusable, as Simpson (35) had suggested more than a century ago; Newton (31) has found the stipe reusable up to twenty times, each time air drying and resterilizing by ethylene oxide gas or soaking in 99 per cent alcohol for at least two days. Newton (31) and Hale (15) also observed Laminaria to soften the revealed the following hierarchy: a first trimester abortion in a clinic specializing in such procedures cost from $135 to $225, depending upon choice of clinic and the commission which the clinic paid to a referring agency. (The uniform clinic fee was not adjusted to reflect whether a patient refused or requested anesthesia, or whether the patient came through referral or not. Some clinics would not accept patients unless appointments had been arranged through a referring agency.) Women requesting a "menstrual extract i o n " - - a lay term among women who chose not to acknowledge that they were pregnant-were generally charged from $35 to $50. T h e clinical procedure is essentially identical to that of an abortion, except that anesthesia is usually not administered. (One physician interviewed--a salaried clinic employee--admitted that he had performed "extractions" on women well into the first trimester of pregnancy if the patient had requested the less costly procedure. Soon afterward the clinic instituted a policy of routine screening of all patients to determine whether a prospective "extraction" was actually a candidate for abortion. A urine analysis will show a positive indication several weeks after conception.) A third procedure is an endobiopsy--identical to the "menstrual extraction" but conventionally performed for diagnostic purposes unrelated to pregnancy. The fee for an endobiopsy--performed by private physicians and not in abortion clinics---ranged from $25 to $45. However, women who belonged to pre-paid health care plans (such as Kaiser-Permanente) could obtain an endobiopsy on demand as a means of terminating pregnancy, so long as they signed a form in which they agreed that the procedure was not being done for the purpose of abortion.

LAMINARIA DIGITATA

tissues of the cervix, a condition facilitating further dilatation of the cervix should that become necessary. This benefit had earlier been documented by Sinclair (36) in 1907, at the same time that his colleagues were abandoning Laminaria in favor of rigid steel dilators. The use of Laminaria tents as dilating agents for uterine evacuation seems now to have gained acceptance for abortions performed during the first trimester of pregnancy. In addition, Laminaria tents have also been employed for cervical dilatation necessitated by procedures for intracavity radiation therapy (11, 14). Second trimester abortions now emerge as the current challenge to the profession, the products of three to s i x months of gestation being too large and well-developed for removal by curettage (vacuum suction or manual). Traditional methods for second trimester abortion involve the premature stimulation of labor; the uterine contents are delivered intact. Procedures have involved hypertonic saline infusion (injected through the patient's abdominal wall), alone, or in conjunction with such chemical aids as prostaglandin and/or oxytocin, which stimulate contractility of uterine muscles. T o this pharmacopoeia has now been added Laminaria tents, used with one, two, or all three of the accepted clinical procedures (2, 4, I0, 12, 16 19, 26). The Japanese, however, view the contemporary American preoccupation with such chemical inducements as primitive. In Japan, second trimester abortion protocols continue to rely on mechanical techniques in which Laminaria tents are the basic tool. The expansion of Laminaria when placed in the cervical passage has been shown to stimulate sufficient uterine contraction for successful completion of second trimester abortion, without the aid-or the hazards--of chemical inducements (30). Manare (29) appears to corroborate the Japanese position. The relative advantage of Laminaria dilatation in terms of patient comfort seems to be of secondary concern in the American literature, which still reveals a preoccupation with "time-saving, . . . . effi-

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ciency," and new tools. ~ T h e recent endorsement of Laminaria for use in first trimester abortions is based on its ability to shorten operating time (15), in addition to a lower morbidity rate when compared with acute surgical dilatation (15, 31). Ironically, these criteria--time-saving and antiseptic qualities--were precisely those stated in the earlier part of the 20th century for discarding Laminaria tents in favor of steel instruments. ECONOMIC HISTORY T h e primary economic use of L. digitara and other species of kelp in the 20th century has been as a source of algin. Algin was inadvertently discovered in Scotland in the 1880's by Stanford when it was produced during experimentation attempting to increase the iodine yield of kelp (25). T h e gelling property of alginic acid was gradually recognized as commercially valuable for use as a stabilizing m e d i u m in drugs and cosmetics; because it is also edible, it became an important component in the preparation of such foods as cheese spreads, ice cream, bakery products, jellies, glazes, puddings, salad dressings, whipping cream, etc. (25, 88). Algin can also be made into textile fibers by extruding a sodium alginate solution into an acid coagulating bath (38). And because algin fibers are alkali-soluble, they can be employed in lace manufacture, being woven into the textile along with cotton or linen fibers and then subsequently washed out. As a fertilizer, seaweed and seaweed ash (which contain varying amounts of potassium, nitrogen and phosphorous) have been used for many centuries in China, Great Britain, France, Canada and other countries with extensive seacoasts (38). Many of the easily available brown algae have also been processed for stock feed; L. digitata, however, was found to have a rather strong laxative effect in chickens (22). 5 Relatively little concern with human factors emerges from the literature. Sinclair (36), however, wrote of Laminaria as the "gentlest" method of dilatation, and Manabe (28) suggests that "the patient [with Laminaria] does not suffer from pain."

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These many uses of kelp have involved chemical properties of the plant rather than the physical characteristics of contraction and expansion which made Laminaria so attractive to the Celts for knife handles and to physicians for surgical tents. A disjunctive literature has gradually developed. One component deals with the biogeographical characteristics (3, 6, 9, 32, 39), a second with the industrial/chemical qualities (17, 20, 21, 22, 25, 38, 40), and a third with the medical/mechanical properties of the plant (e.g., 2, 4, 5, 10, 11, 15, 18, 28, 29, 31). Convergence of an industrial use of Laminaria with its mechanical properties has occurred at least once on a commercial scale, however; impressed by the contracting and hardening qualities of Laminaria (as had been the Celts somewhat earlier), a New England company set u p a factory to produce Laminaria buttons (7). Sewed on shirts, the buttons served well until laundering. On contact with water, their ability to absorb fluid and swell out t o m and beyond---the original diameter of the stipe (that property which made Laminarm so admirably suited for cervical tents) quickly finished the Laminaria button industry. CONCLUSION Over the past one hundred years, this extraordinarily versatile species of seaweed has played a significant role in the prosperity of a number of diverse industries. Recent legalization of abortion in the United States and in much of the rest of the world--serving to accentuate the ageold problem of uterine access---has now brought the Laminaria tent industry into the inventory of viable economic uses of this seaweed. As a factor in "population control," this important aspect of its usefulness is only now coming to be fully realized. LITERATURE CITED 1. Baer, B. F. 1882. Death after dilatation of the cervix uteri with a laminaria tent. Proc. Obstet. Soc. Phila., Feb. 25. 2. Berman, R., et al. 1974. Intra amniotic prostaglandin F-2-alpha Tham salt and the

ECONOMIC BOTANY

Laminaria tent in midtrimester terminadigitata from the Norwegian coast. Norsk tion of pregnancy. Contraception 9 (6), institutt for tang-og tareforskning. Oslo. 635-642. 21. ----. 1956. Preliminary investigation of the 3. Borgensen, F. 1908. The algae-vegetation carbohydrates of Laminaria digitata and of the Faeroese Coasts with remarks on the Fucus serratus. Norsk institutt for tang-og phyto-geography. In Botany of the Faeroes. tareforskning. Oslo. 4. Brenner, W., et al. 1973. Laminaria aug- 22.----. 1958. Experiments on the feeding of mentation of intra amniotic prostaglandin seaweed meal to domestic animals. Norsk F-2 alpha for the induction of midtrimester institutt for tang-og tareforskning. Oslo. abortion. Prostaglandins 3 (6), 879-894. 23. Kelly,, H. A. 1928. Gynecology. N.Y. 5. Cameron, J. C. 1889. The premature induc- 24. Lee, C. A. 1885. Perforation of the cervix tion of labor. In B. C. Hirst (ed.), Ameriuteri by a laminaria tent. New York Med. can Systems of Obstetrics. Vol. 2. J. July. 6. Chapman, V. J. 1944. Methods of surveying 25. Lesser, M. A. 1950. Alginates in drugs and Laminaria beds. J. Mar. Biol. Assoc. cosmetics. Econ. Bot. 4: 317-$21. 7. - - . 1949. Seaweeds and their uses. N.Y. 26. Lischke, J., et al. 1973. Use of Laminaria 8. ----. 1970. T h e algae. N.Y. tents with hypertonic saline aminoinfusion. 9. Cheng, Tien-Hsi. 1969. Production of kelp Am. J. Obstet Gynecol. 116: 586-7. - - a major aspect of China's exploitation of 27. MacLeod, D. H. and C. D. Read. 1955. the sea. Econ. Bot. 23: 215-236. Gynaecology. 5th ed. London. 775-6. I0. Corson, S. 1974. Use of Laminaria tents 28. Manabe, Y. 1971. Laminaria tent for gradwith prostaglandin. Am. J. Obstet. Gyneual and safe cervical dilation. Am. J. Obcol. 120: 852-3. stet. Gynecol. 110: 743-5. 11. Ekbladh, L., et al. 1974. Laminaria tent for 29. Manare, Y., et al. 1973. Uterine contractilcervical dilation prior to intracavitary raity and placental histology in abortion by dium. Cancer 33: 63-5. Laminaria and metreurynter. Obstet. Gy12. Engel, J., et al. 1973. Midtrimester abornecol. 115: 870-1. tion using prostaglandin F 2 alpha oxytocin 30. Neubardt, Selig. 1972. Techniques of Aborand Laminaria. Fertil. Steril. 24: 565-8. tion. Boston. 13. Erbsloeh, J. and J. Brandt. 1950. Uber die 31. Newton, B. W. 1971. Laminaria tent--relic methodik der schwangerschaftsunterbrechof the past or modern medical device. ung aus medizinischer indikation met beTrans. Pac. Coast Obstet. Gynecol. Soc. sonderer berucksichtigung ihrer komplika39: 10-6. tionen. Zentralbl. Gynak. 72: 1382-6. 32. Parke, M. 1948. Growth in Laminaria. J. 14. Ferree, C., et al. 1973. Use of Laminaria Mar. Biol. Assoc. 27: 651-709. digitata in intra cavitary applications for 33. Pommerenke, W. T. 1955. Abortion in Jacarcinoma of the cervix. Radiology 109 pan. Obstet. Gynecol. Surv. 10: 145-174. (1): 222. 34. Schneider, D. M. 1968. Abortion and de15. Hale, Ralph and Ronald Pion. 1972. Lamb population on a Pacific island. In Andrew naria: an underutilized clinical adjunct. P. Vayda (ed.) Peoples and cultures of the Clin. Obstet. Gynecol. 1S: 829-59. Pacific. N.Y. 383--406. 16. Hanson, F. W., et al. 1974. Laminaria digi- 35. Simpson, J. Y. 1864. Tangle tents. Edintara in saline abortions. Obstet. Gynecol. burgh Med. J. 10: 74-5. 43: 761--4. 36. Sinclair, w . J. 1907. The Laminaria tent, with special reference to the industry of 17. Haug, Arne and Arne Jensen. 1953. Seatent-making in Scotland. Caledon. Med. J. sonal variations in chemical composition of (Glasgow). 7: 46-58. Alaria esculenta, Laminaria saccharina, 37. Sloan, C. F. 1863. On the dried stem of Laminaria hyperborea, Laminaria digitata sea tangle (Laminaria digitata) as a subfrom Northern Norway. Norsk institutt for stitute for the tents in ordinary use. Glastang-og tareforskning. Oslo. gow Med. J. 10: 281--4. 18. Hicks, J. B. 1869. On seatangle tent. Practitioner 1: 83. 38. Tressler, D. K. 1951. The marine products of commerce. N.Y. 19. Horowitz, A. 1974. Adjunctive use of Laminaria tents with hypertonic saline induced 39. Tilden, J. E. 1935. The algae and their midtrimester abortion. Contraception 9 (4): life relations. Univ. of Minn. Press. 409--415. 40. Woodward, F. N. 1965. The seaweed indus20. Jensen, Arne. 1955. Geographical and seatry of the future. In E. G. Young and sonal variation in the chemical composition J. F. McLachlan (eds.) Proc. 5th Intl. Seaof Laminaria hyperborea and Laminaria weed Symposium. Halifax.

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