EP0502958A1 - Catheter a profil bas - Google Patents

Catheter a profil bas

Info

Publication number
EP0502958A1
EP0502958A1 EP91900550A EP91900550A EP0502958A1 EP 0502958 A1 EP0502958 A1 EP 0502958A1 EP 91900550 A EP91900550 A EP 91900550A EP 91900550 A EP91900550 A EP 91900550A EP 0502958 A1 EP0502958 A1 EP 0502958A1
Authority
EP
European Patent Office
Prior art keywords
body member
catheter
outer body
distal
proximal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP91900550A
Other languages
German (de)
English (en)
Other versions
EP0502958A4 (en
Inventor
Bandula Wijay
Paolo Angelini
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Leocor Inc
Original Assignee
Leocor Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Leocor Inc filed Critical Leocor Inc
Publication of EP0502958A1 publication Critical patent/EP0502958A1/fr
Publication of EP0502958A4 publication Critical patent/EP0502958A4/en
Withdrawn legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/10—Balloon catheters
    • A61M25/104—Balloon catheters used for angioplasty
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/0043—Catheters; Hollow probes characterised by structural features
    • A61M25/0054—Catheters; Hollow probes characterised by structural features with regions for increasing flexibility
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M2025/0004—Catheters; Hollow probes having two or more concentrically arranged tubes for forming a concentric catheter system
    • A61M2025/0006—Catheters; Hollow probes having two or more concentrically arranged tubes for forming a concentric catheter system which can be secured against axial movement, e.g. by using a locking cuff

Definitions

  • the invention relates to the field of surgery, and more particularly to instruments for facilitating the performance of surgical procedures involving the flow of blood. This technique has been generally de ⁇ scribed as percutaneous transluminal angioplasty.
  • Obstructive coronary artery disease is generally regarded as a serious health problem in the United States and most of the western world.
  • coronary artery bypass graft surgery is generally used.
  • a translumenal coaxial catheter dilation method for dilating atheromatous lesions in peripheral arteries was introduced by Dotter and Judkins. This technique required sequential dilation of stenotic lesions and employed progressively larger dilating catheters.
  • a "Fogarty balloon catheter" was used to perform translumenal arterioplasty.
  • Gruntzig employed earlier techniques using a single double lumen catheter with a nondistensible balloon segment at its tip which was positioned in the lumen at the stenotic segment of a peripheral artery.
  • the elas ⁇ tic balloon segment was then inflated, resulting in compression of the atheromatous lesion in a manner per ⁇ pendicular to the vessel thus dilating the lumen.
  • the balloon remained inflated for ten to fifteen seconds at seven atmospheres internal pressure and was then de ⁇ flated.
  • the translumenal coronary angioplasty technique consists of a catheter system introduced via the femoral artery under local anesthesia.
  • a preshaped guiding catheter is positioned into the orifice of the coronary artery and through this catheter a dilation catheter is advanced into the branches of the coronary artery.
  • the dilation catheter had an elliptical-shaped relatively non-distensible balloon portion near its tip which could be inflated and deflated.
  • the balloon portion was inflated with fluid which compressed the atherosclerotic material in a direction generally perpendicular to the wall of the vessel thereby dilating the lumen of the vessel.
  • the angioplasty catheter can be placed in a stenotic lesions using solely the wire guide if the lesion is proximately lo ⁇ cated to the point of entry in the body.
  • the word "guide” as referred to in this application is directed to both wire guides and guiding catheters separately or as used in tandem.
  • a guide of appropriate size is advanced through the stenotic lesion and the balloon catheter is threaded over it and advanced to the area of the stenosis.
  • the balloon in the catheter is inflated to a high pressure depending on the size of the balloon and the type of stenosis, and the pressure is held for a period of time.
  • the distal and proximal pressure is measured to evaluate the physiolog ⁇ ical conditions of the organ. More specifically, the pressure differential is measured after deflating the balloon and is used as an indication of the degree of dilation achieved.
  • Past designs have employed a stiff catheter tip on the angioplasty catheter which often resulted in pulling the guide out of the stenotic lesion as the catheter was advanced toward the lesion. Separately, in using the angioplasty catheter, it was often neces ⁇ sary to measure the pressure distal to the catheter.
  • Past designs employed a guide closely fitting to the internal cross section of the distal lumen in the cathe ⁇ ter thereby making it difficult to obtain adequate pres ⁇ sure measurements due to the large pressure drops in ⁇ volved as a result of the usage of close clearances.
  • the pressure measurements were of the nature of a dy- namic measurement, the accuracy and frequency response of which was greatly and adversely affected by the pres ⁇ sure drops within the catheter measurement lumen. It
  • Angioplasty catheters used in the past had rela- tively large catheter body diameters which tended to oc ⁇ clude the artery of concern causing reduced blood flow to the lesion or the organ it supplies.
  • cath ⁇ eter is disclosed in U.S. Patent 4,323,071 (Fig 4).
  • Other catheters although using a tapered body, employed a rigid tip which, if the arterial path was particularly tortuous, tended to pull the guide wire from the steno ⁇ sis.
  • One such catheter is disclosed in U.S. Patent 4,413,989 (Fig. 8).
  • Known angioplasty catheters have dilation bal ⁇ loons attached to the catheter body by adhesives or by
  • SUBSTITUTE SHEET heat sealing Most often, these balloons are made out of polyvinylchloride or irradiated polyethylene.
  • Poly- vinylchloride balloons are normally solvent or adhesive bonded to catheter bodies of the same material and poly- ethylene balloons are adhesive bonded or heat shrunk to catheter bodies of the same material, or a blend of polyethylene and polypropylene, so as to obtain catheter body stiffness.
  • Most such catheters have relatively stiff tips as their distal end which often causes the preplaced guide to be pulled out of the lesion area during catheter advancement in tortuous arteries as well intimal damage.
  • Known catheters also contain relatively stiff bodies to carry the balloon adjacent the distal end of the catheter. The stiffness of the catheter body continues in the area of the balloon up to the distal end of the catheter.
  • Known catheters contain balloon lumen bleed holes whereby air can be removed directly out of the balloon cavity and out of the catheter during the filing of the balloon.
  • These additional lumens either in the form of small metal tubes or as a multilumen catheter tube, con ⁇ sumed valuable cross-sectional area of the catheter tube that otherwise could be used for other purposes such as pressure measurements.
  • Known catheter designs have employed an inner and outer tube wherein in the outer tube contains the bal ⁇ loon as an integral portion thereof or a separate bal ⁇ loon which is bonded to the outer tube. The annulus between the inner and outer tubes is used for inflation of the balloon.
  • the inner and outer tubular members of the cathe ⁇ ters of this invention can be formed from a number of flexible, biologically safe, elastomeric or polymeric materials.
  • the inner and outer tubular members are formed from polymeric materials which com ⁇ prise a blend of a hard nylon compound, i.e., including a polyamide, as exemplified by a nylon such as nylon- 11, nylon-12, etc., and a soft nylon compound comprising a block copolyamide, such as a polyether-polyamide co- polymer, as exemplified by a polyether-nylon-12 copoly- mer.
  • the outer tubular member of this in ⁇ vention also can be formed using a polymeric composition comprising solely a polyether-polyamide copolymer, such as the previously mentioned polyether-nylon-12 copoly ⁇ mer.
  • the apparatus of the present invention is an angioplasty catheter comprising an inner and outer tubu ⁇ lar members, each having a proximal and distal segment.
  • the distal segment of the outer body member is softer than the proximal segment of the outer body member.
  • the distal segment of the inner body member is softer than the proximal segment of the inner body member.
  • the proximal segment of the inner body member is harder than the proximal segment of the outer body member.
  • the distal segment of the outer body member is softer than the distal segment of the inner body member.
  • a reducing taper is provided between the proximal and distal segments of the inner body member.
  • a similar reduction is provided between the proximal and distal segments of the outer body member.
  • the distal segment of the inner body member extends beyond the distal seg ⁇ ment of the outer body member.
  • a balloon spans the distal segments of the inner and outer body members, effectively closing off an annulus created between the nested inner and outer body members.
  • the balloon can be selectively inflated during the angioplasty procedure.
  • the catheter presents a low profile.
  • the combination of hardnesses provides for sufficient body strength to allow pushability and torque resistance, combined with sufficient distal softness to avoid trauma to the arter ⁇ ial walls during insertion.
  • Figure 1 is a sectional view of the catheter.
  • Catheter C has a tubular inner body member, designated generally as 10, and a tubular outer body member, designated gener ⁇ ally as 12.
  • Inner body member 10 has a proximal segment 14 and a distal segment 16.
  • Outer body member 12 has a proximal segment 18 and a distal segment 20.
  • tapers 22 and 24 are located, respectively, on the inner body member 10 and outer body member 12. Taper 22 is located between seg ⁇ ments 14 and 16, while taper 24 is located between seg ⁇ ments 18 and 20. Tapers 22 and 24 are preferably lo ⁇ cated within close proximity to each other. As seen in Figure 1, segment 16 extends beyond segment 20. A bal ⁇ loon 26 spans between segments 20 and 16. Balloon 26 has a distal neck 28 mounted to segment 16. In the
  • distal neck 28 ends contempo ⁇ raneously with the end of segment 16.
  • the distal end of segment 20 contains a reduced-profile shoulder 30.
  • the proximal neck 32 is mounted to shoulder 30. The result is that when the balloon 26 is deflated, the profile of the catheter C distally of taper 24 does not exceed the profile of segment 20, which preferably is less than 0.0420".
  • a radiopaque band 34 preferably made from rhen- ium and tunsten, is mounted to segment 16. The purposes of facilitating proper location of the balloon during the angioplasty procedure.
  • the balloon 26 can preferably be made of a poly ⁇ ethylene or polyester material, with a wide variety of wall thicknesses, including but not limited to 2, 2- 1/2, 3 and 3-1/2 mm.
  • segment 14 is made from a material that is 70 percent hard nylon compound.
  • the preferred hard nylon compound containing 30 percent bismuth oxychloride and color additive, as used in this specification refers to a product available from Huels Corporation which contains "nylon 12-L2101F.” Its typi ⁇ cal Shore D hardness is 75 and the tensile stress is in the range of 7300 psi.
  • the nylon in the hard nylon compound which is preferably nylon 12, is based on the lauryl lactum monomer. Different grades are derived through variations in the molecular weight of the homo ⁇ polymers; i.e., high-viscosity extrusion grades, as well as low-viscosity grades for injection molding.
  • the lauryl lactum is copolymerized with various components to yield the approximate Shore D hardness of 75 and tensile strength of 7300 psi. It is understood that the percentage of hard nylon compound can vary in a range from 70 percent by plus or minus 10 percent.
  • the other ingredient is soft nylon compound, containing 30 percent bismuth oxychloride and color additive. The preferred nylon in the soft nylon compound as used in this
  • SUBSTITUTE SHEET application is preferably nylon E47M-S3 made by the Huels Corporation of Piscataway, NJ. This material is chemically characterized as block copolyamides.
  • the polymer chains consist of alternating rigid polyamide 12 segments and flexible polyether segments. By varying the proportions of the polyamide 12 to the polyether segments, grades of different hardnesses and flexibility can be obtained.
  • the preferred embodiment is a material having a Shore D hardness of 47 and tensile stress of about 2900 psi.
  • Each of the components of the catheter, except the balloon 26, are made from a blend of hard and soft nylon compounds, as indicated in this application. Where the percentage is given as hard nylon compound, the balance of the material is soft nylon compound.
  • the opposing segment 18 on the outer body member 12 is pref ⁇ erably made of 40 percent, plus or minus 10 percent, hard nylon compound.
  • the preferred Shore D hardness of segment 14 is 67, plus or minus 10; the preferred hard ⁇ ness for segment 18 on the Shore D scale is 58, plus or minus 10.
  • the preferred hardness on the Shore D scale for segment 16 is 52, plus or minus 10, while the preferred hardness on the Shore D scale for segment 20 is 47, plus or minus 10.
  • 16, 18 and 20 are of the order of 5900, 4600, 4600, and 2900 psi, respectively.
  • the material composition with respect to the hard nylon compound found in the various segments can range in hard nylon compound content plus or minus 5 percent, with the exception of segment 20, in which the hard nylon compound content can range between about 0-5 percent.
  • segment 20 is preferably made of 100 percent soft nylon compound, while segment 16 is preferably 17 percent hard nylon compound.
  • SUBSTITUTE SHEET ferred range is 3-15 cm. Lengthening segment 20 length ⁇ ens segment 16 and vice versa.
  • the net result of the catheter disclosed above is a low-profile angioplasty catheter that has sufficient body strength to have good pushability characteristics, and further having a soft distal end to improve track- ability and decrease the possibilities of patient trauma on the arterial wall; such soft distal end also prevents the pulling out of the guidewire.
  • segment 14 can be con ⁇ nected to segment 16 by virtue of a discrete joint or, alternatively, by a gradual blending of one material into another. The same applies for the material change between segments 18 and 20. Segment 16 is of sufficient strength so that it does not inwardly distend during inflation of balloon 26.
  • Tubular inner body member 10 has a central lumen 36, which extends for the length of the catheter.
  • Lumen 36 can be used to advance the catheter C over a guide- wire as large as about 0.020" (not shown). Alterna ⁇ tively, with the guidewire removed, lumen 36 can be used to perfuse fluids distally of inflated balloon 26. The patient's own blood may be recycled through a suitable blood pump (not shown) through lumen 36 and distally of inflated balloon 26 during balloon, angioplasty. Tube 16 is sufficiently strong to avoid being distended, thereby constricting lumen 36 during inflation of balloon 26. At the same time, the portion of the catheter C distally of tapers 22 and 24 as an assembly is relatively soft to increase trackability and reduce trauma. The softness of the assembly referred to in the previous sentence can also be varied by adjusting the length of segment 20 in the preferred range of about 3-15 cm. The longer the length of segment 20, the more flexible is the overall tip assembly of the catheter C.
  • segment 18 is made from a substantially similar material as segment 20, preferably 40 percent hard nylon compound. Therefore, as previously stated, proximal outer body member 18 would be of the composition previously de ⁇ scribed in the other preferred embodiment, while distal segment 20 would be substantially the identical mate ⁇ rial. In this type of construction, there would be no joint between segments 18 and 20. This is distinguished from the other preferred embodiment where there would be a transition of materials between proximal outer body segment 18 and distal outer body segment 20. This tran ⁇ sition would occur adjacent and proximally of taper 24. The transition between proximal inner body member 14 and distal inner body member 16 will occur proximally and adjacent to taper 22.
  • the distal outer body member 20 is actu ⁇ ally harder than the distal inner body member 16.
  • the relationship between the proximal inner and outer body members in this alternative preferred embodiment is the same as in the previously described embodiment. Stated differently, there has been no change in the preferred materials with this second alternative insofar as the proximal inner body member 14 and the proximal outer body member 18 are concerned.
  • This alternative prefer ⁇ red embodiment provides a little bit more stiffness at the distal end of the catheter, coupled with sufficient flexibility to minimize patient trauma and improve trackability.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Anesthesiology (AREA)
  • Hematology (AREA)
  • Biophysics (AREA)
  • Pulmonology (AREA)
  • Engineering & Computer Science (AREA)
  • Veterinary Medicine (AREA)
  • Biomedical Technology (AREA)
  • Public Health (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Child & Adolescent Psychology (AREA)
  • Vascular Medicine (AREA)
  • Materials For Medical Uses (AREA)
  • Media Introduction/Drainage Providing Device (AREA)

Abstract

Cathéter d'angioplastie comprenant des éléments tubulaires intérieur (10) et extérieur (12), présentant chacun des segments proximal et distal. Le segment distal (20) de l'élément de corps extérieur (12) est plus souple que le segment proximal (18) de ce dernier (12). De même, le segment distal (16) de l'élément de corps intérieur (10) est plus souple que le segment proximal (14) de ce dernier (10). Le segment proximal de l'élément de corps intérieur est plus dur que le segment proximal de ce dernier. Le segment distal (20) de l'élément de corps extérieur (12) est plus souple que le segment distal (16) de l'élément de corps intérieur (10). Un ballon (26) couvre les segments distaux (16, 20) des éléments de corps intérieur et extérieur, fermant efficacement un anneau créé entre les éléments de corps intérieur et extérieur emboîtés. La combinaison de duretés donne une résistance suffisante au corps pour permettre une capacité de poussée, combinée à une souplesse distale suffisante permettant d'éviter un trauma aux parois artérielles pendant l'insertion.
EP19910900550 1989-11-28 1990-11-19 Low profile catheter Withdrawn EP0502958A4 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US44215789A 1989-11-28 1989-11-28
US442157 1989-11-28

Publications (2)

Publication Number Publication Date
EP0502958A1 true EP0502958A1 (fr) 1992-09-16
EP0502958A4 EP0502958A4 (en) 1992-09-30

Family

ID=23755750

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910900550 Withdrawn EP0502958A4 (en) 1989-11-28 1990-11-19 Low profile catheter

Country Status (3)

Country Link
EP (1) EP0502958A4 (fr)
JP (1) JPH05501658A (fr)
WO (1) WO1991008014A1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09504980A (ja) * 1994-03-10 1997-05-20 シュナイダー・（ユーエスエイ）・インコーポレーテッド 可変剛度の軸を有するカテーテル
EP0674912A1 (fr) * 1994-03-31 1995-10-04 Leocor, Inc. Cathéter à double passage coaxial
CA2223990C (fr) * 1995-06-07 2007-01-30 Cardima, Inc. Sonde-guide destinee au sinus coronaire
US5836912A (en) * 1996-10-21 1998-11-17 Schneider (Usa) Inc. Catheter having nonlinear flow portion
JP4141595B2 (ja) * 1999-07-22 2008-08-27 株式会社カネカ 拡張カテーテル

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4819751A (en) * 1987-10-16 1989-04-11 Baxter Travenol Laboratories, Inc. Valvuloplasty catheter and method
EP0330376A2 (fr) * 1988-02-23 1989-08-30 C.R. Bard, Inc. Système d'angioplastie à ballonnet pour artères cérébrales
WO1989008471A1 (fr) * 1988-03-07 1989-09-21 Leocor, Inc. Catheter a ballon de faible profil pourvu d'un fil de guidage pour angioplastie

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4385635A (en) * 1980-04-25 1983-05-31 Ruiz Oscar F Angiographic catheter with soft tip end
JPS6010647A (ja) * 1983-06-29 1985-01-19 Nec Corp 混成集積回路装置
JPS61182247A (ja) * 1985-02-08 1986-08-14 Nippon Telegr & Teleph Corp <Ntt> Ｉｃパツケ−ジ
JPS61239649A (ja) * 1985-04-13 1986-10-24 Fujitsu Ltd 高速集積回路パツケ−ジ
US4616653A (en) * 1985-07-30 1986-10-14 Advanced Cardiovascular Systems, Inc. Balloon dilatation catheter with advanceable non-removable guide wire
US4665925A (en) * 1985-09-13 1987-05-19 Pfizer Hospital Products Group, Inc. Doppler catheter
JPS63212374A (ja) * 1987-02-27 1988-09-05 テルモ株式会社 拡張体付カテ−テル

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4819751A (en) * 1987-10-16 1989-04-11 Baxter Travenol Laboratories, Inc. Valvuloplasty catheter and method
EP0330376A2 (fr) * 1988-02-23 1989-08-30 C.R. Bard, Inc. Système d'angioplastie à ballonnet pour artères cérébrales
WO1989008471A1 (fr) * 1988-03-07 1989-09-21 Leocor, Inc. Catheter a ballon de faible profil pourvu d'un fil de guidage pour angioplastie

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9108014A1 *

Also Published As

Publication number Publication date
JPH05501658A (ja) 1993-04-02
WO1991008014A1 (fr) 1991-06-13
EP0502958A4 (en) 1992-09-30

Similar Documents

Publication Publication Date Title
US4921483A (en) Angioplasty catheter
US9084875B2 (en) Single piece double wall dilation balloon catheter
US6270522B1 (en) High pressure catheter balloon
US6344029B1 (en) Catheter with enhanced flexibility
US6695809B1 (en) Catheter balloon with a discontinuous elastomeric outer layer
JP3713048B2 (ja) 補強された長円形状の横断面を備えたカテーテル
US5304132A (en) Limacon geometry balloon angioplasty catheter systems and method of making same
US8905967B2 (en) Catheter having a readily bondable multilayer soft tip
CA2511028C (fr) Modele de tige de sonde a ballonnet
US8834510B2 (en) Catheter with stepped skived hypotube
US20100042199A1 (en) Dilation balloon catheter and methods of use thereof
US6991626B2 (en) Polymer jacket with adhesive inner layer
US20020018866A1 (en) Polyether block amide catheter balloons
US5338296A (en) Catheter and sheath assembly
EP1596898A2 (fr) Sonde a ballonnet
JPH10504207A (ja) 高強度の近位シャフトを有する管腔内カテーテル
US7273487B1 (en) Balloon catheter having a multilayered shaft with variable flexibility
CN213100299U (zh) 一种耐折性血管扩张球囊导管
EP0502958A1 (fr) Catheter a profil bas
JP4815657B2 (ja) 医療用ポリマーブレンド材料およびこの材料を用いた医療用バルーン
WO2000012145A1 (fr) Sonde a ballonnet contenant de la polycetone aliphatique
NO901227L (no) Angioplastisk kateter.

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19920526

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB IT

A4 Supplementary search report drawn up and despatched

Effective date: 19920813

AK Designated contracting states

Kind code of ref document: A4

Designated state(s): DE ES FR GB IT

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19921016

R18W Application withdrawn (corrected)

Effective date: 19921016