Eleven-year experience with tibiotibial bypass: An unusual but effective solution distal tibial artery occlusive disease and limited autologous vein

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1 Eleven-year experience with tibiotibial bypass: An unusual but effective solution distal tibial artery occlusive disease and limited autologous vein to Ross T. Lyon, MD, Frank J. Veith, MD, Ben U. Marsan, MD, Kurt R. Wengerter, MD, Thomas F. Panetta, MD, Michael L. Matin, MD, Jamie Goldsmith, RN, Steven P. Rivers, MD, and William Suggs, MD, New York, N.Y. Purpose: The absence of sufficient length of suitable autologous vein occasionally prohibits the treatment of severe distal lower extremity arterial occlusive disease with a standard distal bypass originating from the common femoral artery. During the past 11 years, we have therefore selectively performed short distal bypasses originating from the infrapopliteal arteries in patients with limb-threatening ischemia and occlusive lesions limited to the distal tibial and peroneal arteries. This report summarizes our experience with these tibial artery based distal bypasses. Methods: Forty-two distal lower extremity arterial bypasses originating from infrapopliteal arteries in 41 patients were performed over an ll-year period. Autologous vein was used as the bypass conduit in all cases. Extensions from a more proximal bypass were excluded. Results: The primary patency rate of these tibiotibial bypasses was 77% at 1 year and 62% after 5 years. The limb salvage rate after 5 years was 74%. The perioperative mortality rate was low (2%), but the 5-year patient survival rate (64%) was similar to that with more standard lower extremity arterial reconstructive procedures. Conclusions: Tibiotibial bypass is an effective limb salvage procedure in carefully selected patients with distal tibial artery occlusive disease and limited autologous vein. It offers a durable means of distal revascularization in circumstances in which a standard operation might not be desirable or possible. (J VASC SURG 1994;20:61-9.) The preferred site of origin for lower extremity distal arterial bypasses has traditionally been the common femoral artery. Use of this vessel usually allows prolonged bypass patency with few inflow problems. However, several circumstances make use of more distal inflow sites advantageous. Limited available autologous vein, previous surgical groin scarring, infection, or severe obesity, together with the absence of significant superficial femoral From the Montefiore Medical Center of the Albert Einstein College of Medicine (Drs. Lyon, Veith, Wengerter, Panetta, Marin, Suggs, and Rivers and Ms. Goldsmith), and Flushing Medical Center (Dr. Marsan), New York. Presented at the Forty-seventh Annual Meeting of the Society of Vascular Surgery, Washington, D.C., June 8-9, Reprint requests: Ross T. Lyon, MD, Assistant Professor of Surgery, The Albert Einstein College of Medicine, 1575 BlondeU Ave., Bronx, New York Copyright 1994 by The Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter /94/$ ,4/1/53766 artery stenotic or occlusive lesions, are reasons to place the origin of a lower extremity arterial bypass distal to the common femoral artery. Use of distal inflow sites enables short vein bypasses, which may obviate the need to use diseased or small marginal portions of available vein and may therefore in certain cases provide superior patency rates compared with longer bypasses to similar distal vessels. These considerations prompted us to advocate preferential use of the superficial femoral and popliteal arteries as inflow sites for distal bypasses when these arteries were free of stenotic lesions. Our initial 5-year experience with these distal origin bypasses was reported in ~ These favorable results coupled with the restriction of limited length of available autologous vein led us to perform even shorter bypasses originating from the infrapopliteal vessels when unobstructed flow to these arteries was present. Dartza 2 in 1982 reported the use of tibial artery-based bypasses in 10 patients with 61

2 62 Lyon et al. July 1994 t i'i!ii~!~!i Fig. 1. Intraoperative arteriogram of proximal to distal anterior tibial artery bypass in patient with partial forefoot necrosis and absent pedal arterial arch. This bypass has remained patent for more than 4 years. Fig. 2. Posterior tibial to lateral plantar artery bypass in patient requiring partial foot amputation. Duration of patency now greater than 3 years. occlusive lesions limited to the distal crural and pedal vessels. Our use and results of these tibiotibial artery bypasses were first reported in 1985) Over the past 11 years we have performed a total of 42 of these procedures (Figs. 1 to 3). This article reviews the indications for and our results with these extremely short distal tibiotibial bypasses. PATIENTS AND METHODS From November 1981 to December 1992, we performed 2473 lower extremity arterial bypass procedures, of which 42 (1.7%) originated from the infrapopliteal arteries. Medical records, angiograms, and vascular laboratory examination results of all patients undergoing a lower extremity bypass originating from the infrapopliteal vessels (tibioperoneal

3 Volume 20, Number 1 Lyon et al. 63 trunk, anterior tibial, posterior tibial, and peroneal arteries) were retrospectively reviewed. Additional follow-up data on these tibiotibial bypasses were obtained from our computerized vascular registry. Extensions from a simultaneous or previous distal bypass were excluded. Patient characteristics. Average age of patients was 60 years, although nine were less than 50 years old (range 29 to 80 years). Twenty-seven of 41 patients were men, 37 (90%) had diabetes, of whom 26 (63%) had insulin-dependent diabetes and 8 (20%) had juvenile onset diabetes. Seven had chronic kidney dysfunction (serum creatinine level > 3.0 mg/dl), five of whom had end-stage renal disease (four undergoing dialysis and one with a functioning kidney transplant). All but 11 admitted to extensive smoking habits. Nine had previous clinical myocardial infarctions, one had a previous stroke. Two had previous contralateral amputations. Four had undergone prior coronary artery revascularization procedures. Indications. All patients had absent pedal pulses and impending limb loss caused by ischemia. Most (39 of 42) had open nonhealing foot wounds or gangrene, 19 of which were clinically infected. These open wounds had failed to show signs of healing despite aggressive wound care consisting of wound debridement, frequent dressing changes, antibiotics, and avoidance of ambulation. Three other patients had ischemic rest pain and impending tissue loss, but no open wounds or overt gangrene. Angiography revealed segmental occlusion of all three tibial vessels in all but three patients who had a patent peroneal artery but no direct inflow into the foot. Inflow to the proximal tibial vessels was via native unobstructed arteries in 32 instances and from a more proximal arterial inflow procedure in 10 patients (Table I). More standard arterial bypasses with autologous vein originating from the femoral or popliteal arteries were not performed primarily because of limited available autologous vein as the result of previous vein harvesting procedures, vein ligation and stripping, phlebitis, or varicosities. Distal sites of origin of bypasses were used instead of splicing small segments of vein together or use of prosthetic conduits for more proximal origin bypasses. In seven instances, tibiotibial bypasses were done preferentially despite the presence of longer lengths of potentially suitable greater saphenous vein. Noninvasive vascular assessment. All patients had segmental lower extremity arterial occlusion pressure measurements and arterial plethysmographic pulse volume recordings obtained before and after operation. Fig. 3. Follow-up arteriogram of proximal to distal anterior tibial artery bypass done 11/2 years after operation. This bypass has remained open despite development of outflow stenosis and absence of intact pedal arch. Proximal anastomotic sites. Bypasses originated from the tibioperoneal trunk in two instances, the anterior tibial artery in 28, the posterior tibial artery in nine, and the peroneal artery in three patients (Fig. 4). Distal outflow. Distal anastomoses were to the distal tibial vessels in 20 cases (anterior tibial = 13,

4 64 Lyon et al. July 1994 Table I. Inflow procedures proximal to tibiotibial bypasses Location Type of procedure No. Aortoiliac Graft 1 Endarterectomy 1 Femoropopliteal Bypass 5 Endarterectomy 1 Balloon angioplasty 1 Tibial Balloon angioplasty 1 Total Inflow procedures i0 posterior tibial = 6, peroneal = 1), and to pedal vessels in 22 instances (dorsalis pedis = 16, plantar or tarsal arteries = 6, Fig. 4). Many of these grafts were to short, isolated arterial segments within the foot. Distal arteriovenous fistulas were not used to augment flow. Operative technique. Standard tibial artery exposure techniques, systemic heparinization, selective use of a pneumatic arterial tourniquet, 1.25 to 2.5 x magnification, 2 to 3 cm long end-to-side proximal and distal anastomoses, and routine use of completion angiography were used during operative procedures. Regional anesthesia techniques were used in 32 of 43 procedures. Bypass conduits. Autologous vein was the conduit for all bypasses. Upper extremity vein was used in two instances, and lesser saphenous vein was used in one. Antithrombotic medications. Three patients were given heparin after operation because of concern about limited outflow and graft thrombosis. Long-term oral anticoagulation with warfarin (Coumadin) was not used. All patients were instructed to take 325 mg aspirin daily and 75 mg dipyridamole (Persantine) three times a day as outpatients. Graft patency. Postoperative graft patency was determined by a combination of clinical examination, when pedal pulses were easily palpable, and by noninvasive testing (arterial pulse volume recordings or duplex scanning) when pulses were either difficult to feel or absent. Loss of a previously palpable pulse distal to the bypass or absence of flow within a graft on duplex examination or angiography were criteria used to determine bypass failure. Date of graft closure was arbitrarily defined as the midpoint in time between the date the graft was last known to be patent and when the graft was documented to be closed. Four patients with patent grafts were lost to follow-up at 1 year (n = 1), 3 years (n = 1), and 4 years (n = 2) after bypass. Bypass patency, limb salvage, and survival rates were calculated with life-table analysis.* Functional status. All patients were ambulatory 1 month before undergoing bypass procedures. RESULTS All patients with patent bypasses regained the ability to ambulate within 6 months of undergoing bypass procedures. Overall, the primary bypass patency rate at the time of hospital discharge was 82%. Average ankle/brachial pressure index increased from before operation to after operation in patients with patent grafts (mean + S.D.). Forefoot pulse volume recording amplitudes increased from 4.3 _+ 3.1 mm to mm before versus after operation, respectively. The primary bypass patency rate at 1 and 5 years was 77% and 62%, respectively (Table II, Fig. 5), and the corresponding limb salvage rate was 81% and 74% (Table III). The patient survival rate at 1 and 5 years was 86% and 64%, respectively (Table IV). Three of the patients had enzymatic evidence of a postoperative myocardial infarction, one of whom died on postoperative day 23, resulting in a 30-day operative mortality rate of 2%. Other incidental postoperative complications included pneumonia (n = 1), wound infection (n = 1), pulmonary edema (n = 1), sacral decubiti (n = 1), late death (n = 1). Six bypasses occluded within 30 days after operation, three while the patients were receiving heparin because of concern about severely limited outflow. Thrombectomy and revision (graft extension to the plantar artery) and subsequent unsuccessful popliteal-to-plantar artery bypass and amputation were performed in one patient with acute postoperative graft thrombosis. Three of the five bypasses in patients with end-stage renal disease occluded within 30 days of surgery. Both of the other patients died within 1 year of bypass procedures, one of which required an amputation because of progressive foot necrosis, despite a patent bypass. Excluding these results in patients with end-stage renal disease, 83% of the tibiotibial bypasses were patent at 1 year and 67% were patent after 5 years. Twelve patients required transmetatarsal amputation, and 28 required one or more toe amputations because of preexisting necrosis. Below-the-knee amputation was required after acute graft occlusion in all but two patients (one of whom died prior to discharge). Three patients with patent bypass grafts required below-the-knee amputations during opera-

5 JOURNAL Ot3 VASCULAR SURGERY Volume 20, Number 1 Lyon et al. 65 BYPASSES AND ANASTOMOTIC SITES Proximal Anastomosis Distal Anastomosis (2) TPT ol AT (13) (28) AT ~ ~ PT (6) (9) PT ~ P (1) (3) P k~a"-'-'-~ ~ 1 Pedal Vessels (6) TPT -- tibio-peroneal trunk AT = anterior tibial PT-- posterior tibial P -- peroneal Fig. 4. Diagrammatic representation of all tibiotibial bypasses and anastomotic sites. Table II. Primary bypass patency life-table Cumulative Standard Interval No. of grafts No. of grafts Withdrawn Interval patency error (mo O at risk failed patent* patency (%) (%) *Withdrawn while patent bacause of death (n = 9), insufficient duration offouow-up (n = 7), lost to follow-up (n = 4), and amputation (n = 3). don because of progressive foot infection and tarsal bone destruction. Five bypasses failed after complete healing of foot lesions, but only two of these patients underwent amputation. A total of 10 ipsilateral major amputations were performed on patients with occluded bypass grafts during the follow-up period, all were at the below-knee level. Twenty-eight of 29 open foot wounds healed in patients whose bypasses remained open for more than 1 month. DISCUSSION Lower extremity bypass techniques have evolved over the past 25 years and have enabled progressively more distal bypasses to be performed with improved operability, bypass patency, and limb salvage rates, ss Formerly, it was believed that bypasses should originate from the common femoral artery, with distal anastomoses to the popliteal artery if possible, preferably with two- or three-vessel runoff to the foot. Since that time, bypasses to the distal tibial and pedal arteries and their branches with limited outflow have proven effective with 3-year primary patency rates more than 70% and limb salvage rates in excess of 85%. 71 Selective use of more distal sites of origin such as the superficial femoral and popliteal arteries has facilitated the performance of autologous vein bypasses by allowing use of otherwise inadequate lengths of suitable vein},111s These distal origin bypasses have been shown to have long-term patency

6 66 Lyon et al. luly PRIMARY BYPASS PATENCY # of Grafts at Risk T T T T 62% (82 /o)177%) (77%) (70%) (62%) (62%) I i i,, l I I I Months Fig. 5. Diagrammatic representation of primary bypass patency results. 72 Table III. Limb salvage fife-table Cumulative Withdrawn Interval limb Standard Interval No. of limbs No. of without limb salvage error (too) at Hsk amputations amputation ~ salvage (%) (%) ] ~Withdrawn because of death (n = 10), insufficient duration of follow-up (n = 9), lost to follow-up (n = 5). rates similar to bypasses originating from the common femoral artery, lals Bypass failure has usually been the result of either infrequent early technical problems, or the subsequent development of graft related lesions or progression or distal disease),ls~6 Relatively few grafts were thought to have failed because of progression of proximal occlusive disease. This report describes our limited experience with even more distal origin bypasses originating from the infrapopliteal arteries primarily in situations that otherwise would have required a more proximally based prosthetic bypass graft or amputation. Many of these bypasses were performed on severely limited outflow tracts consisting of short segments of isolated vessels in the distal leg and foot where a patent pedal arch was not present. More conventional revascularization procedures would have required considerably longer lengths of suitable vein. With the increased frequency of coronary artery and prior lower extremity revascularization procedures, the amount of autologous saphenous vein available for use is frequently limited. Additionally, preexisting disease of the saphenous veins may further reduce the amount of usable autologous conduit or reduce bypass patency if suboptimal vein is used. 17 In the absence of significant proximal occlusive lesions, a

7 Volume 20, Number 1 Lyon et al. 67 Table IV. Survival life-table Cumulative Standard Interval No. of patients Withdrawn while Interval survival error (too.) at risk Deaths alive* survival (%) (%) ~Withdrawn before death because of insufficient duration of follow-up (n = 14), lost to follow-up (n = 5). short segment tibiotibial bypass may be preferred in these cases. An added benefit is that short bypasses may be less prone to thrombosis. 18 Retrospective evaluation of more standard lower extremity bypasses has revealed that as many as 63% of bypass failures are the result of intragraft problems. 19 These lesions may be less common in tibiotibial bypasses because of the shorter lengths of vein. In some instances the use of a short direct tibiotibial bypass obviates the need for routing conduits over bony prominances or across fascia/ planes, which are possible problem sites because of extrinsic compression. Other advantages of a short bypass are the potential for avoiding hostile sites of previous surgical procedures or infection and for limiting the magnitude and risks of operative procedures by minimizing the extent of surgical dissection and exposure and operative time. Nevertheless, bypass failure caused by progression of inflow disease becomes more likely the more distal a bypass is originated. Tibiotibial bypasses are therefore more likely to fail because of inflow problems than more traditional lower extremity bypasses that originate from the common femoral artery. For this reason, we do not advocate the preferential use of a tibiotibial bypass when enough suitable length of autologous vein is present for a more proximally based bypass. Additionally, use of these smaller inflow arteries makes the proximal anastomosis of a tibiotibial artery technically demanding. As a result, many of the techniques currently used for constructing distal anastomoses to crural and pedal arteries and their branches must also be used for the proximal anastomoses when performing a tibiotibial bypass. These include the use of fine instruments and sutures, optical magnification and the avoidance of dissection and clamping injuries. We have found the use of a pneumatic arterial tourniquet as originally described by Bernhard et al. 20 to be especially helpful not only in obtaining hemostasis but also in eliminating the need for circumferential arterial dissection and arterial occlusive maneuvers. Because bypass patency at distal sites is highly dependent on the type of conduit used, the ability to avoid the use of a prosthetic graft or conduit other than autologous vein is likely to outweigh the potential disadvantages of use of a more distal artery for inflow. Even in the presence of inflow lesions of the superficial femoral or popliteal arteries, balloon angioplasty or a proximal prosthetic bypass in conjunction with a distal tibiotibial autologous vein bypass may be preferable to a long distal prosthetic bypass to a tibial or pedal vessel when insufficient autologous vein is available for a more standard distal bypass. In this study, 10 patients had more proximal inflow procedures before undergoing tibiotibial bypass resulting in durable limb salvage in eight of these patients. Overall, the 1- and 5-year cumulative patency and limb salvage rates achieved with these distal origin bypasses are comparable to many of the contemporary series reporting on distal bypass outcomes with more proximal inflow sites to similar distal vessels Furthermore, these results are considerably better than the patency rates of prosthetic bypasses to similar vessels.2325 It is on this basis that we recommend the selective use of tibiotibial bypass. In summary, tibiotibial bypass is an effective alternative revascularization procedure in carefully selected patients with distal tibial artery occlusive disease and limited suitable autologous vein. It avoids the need for amputation and offers a durable means of distal revascularization in circumstances in which a standard operation might not be desirable or possible.

8 68 Lyon et al. July 1994 REFERENCES 1. Veith FJ, Gupta SK, Samson RH, et al. Superficial femoral and popliteal arteries as inflow sites for distal bypasses. Surgery 1981;90: Danza R. The use of by-pass grafts for obstructive lesions of tibial and peroneal arteries. J Cardiovasc Surg 1982;23: Veith FJ, Ascer E, Gupta SK, et al. Tibiotibial vein bypass grafts: a new operation for limb salvage. J VAsc SURG 1985;2: Rutherford RB, Flannagan P, Gupka SK, et al. Suggested standards for reports dealing with lower extremity ischemia. J VAsc SURG 1986;4: Veith FJ, Gupta SK, Samson RH, et al. Progress in limb salvage by reconstructive arterial surgery combined with new or improved adjunctive procedures. Ann Surg 1986; 194: Maini BS, Mannick JA. Effect of arterial reconstruction on limb salvage: a 10-year appraisal. Arch Surg 1978;113: Taylor LM Jr, Edwards JM, Porter JM. Present status of reversed vein bypass grafting: five-year results of a modern series. J VASC SURG 1990;11: Leather RP, Shah DM, Chang BB, Kaufman JL. Resurrection of the in-situ saphenous vein bypass 1000 cases later. Ann Surg 1988;208: Bergamini TM, Towne JB, Bandyk DE, et al. Experience with in-situ saphenous vein bypass during 1981 to 1989: determinant factors of long-term patency. J VAsc SURG 1991;13: Andros G, Harris RW, Salles-Cunha SX, et al. Bypass grafts to the ankle and foot. J VAsc SURG 1988;7: Veith FJ, Gupta SK, Wengetter KR, et al. Changing arteriosclerotic disease patterns and management strategies in lower-limb-threatening ischemia. Ann Surg 1990;212: Schuler JJ, Fannigan DP, Williams LR, et al. Early experience with popliteal to infrapopliteal bypass for limb salvage. Arch Surg 1983;118: Sidaway AN, Menzoian 10, Cantelmo NL, et al. Effect of inflow and outflow sites on the results of tibioperoneal vein grafts. Am J Surg 1986;152: Rosenbloom MS, Walsh JJ, Schuler JJ, et al. Long-term results of infragenicular bypasses with autogenous vein originating from the distal superficial femoral and popliteal arteries. J VASe SUV.G 1988;7: Wengerter KR, Yang DM, Veith FJ, et al. A twelve-year experience with the popliteal to distal artery bypass: the significance and management of proximal disease. J VASC SURG 1992;15: Sanchez LA, Gupta SK, Veith FJ, et al. A ten-year experience with one hundred fifty falling or threatened vein and polytetrafluoroethylene bypass grafts. J VASC SURG 1991; 14: Panetta TF, Marin ML, Veith FJ, et al. Unsuspected preexisting saphenous vein disease: an unrecognized cause of vein bypass failure. J Vasc SURG 1992;15: Ascer E, Veith FJ, Gupta SK, et al. Short vein grafts: a superior option for arterial reconstructions to poor or compromised outflow tracts? J Vasc SURG 1988;7: Donaldson MC, Mannick JA, Whitemore AD. Causes of primary graft failure after in situ saphenous vein bypass grafting. J VASC SURG 1992;15: Bernhard VM, Boren CH, Towne JB. Pneumatic tourniquet as a substitute for vascular clamps in distal bypass surgery. Surgery 1980;87: Shah DM, Darling RC, Chang BB, et al. Is long vein bypass from groin to ankle a durable procedure? An analysis of a ten-year experience. J VAsc SURG 1992;15: Harrington EB, Harrington MF, Shanger H, et al. The dorsalis pedis bypass: moderate success in difficult situations. J Vasc SUnG 1992;15: Quifiones-Baldrich WJ, Prego AA, Ucelay-Gomez R, et al. Long-term results of infrainguinal revascularization with polytetrafluoroethylene: a ten year experience. J VAsc SURG 1992;16: Veterans Administration Cooperative Study Group 141. Comparative evaluation of prosthetic, reversed and in situ vein bypass grafts in distal popliteal and tibial-peroneal revascularization. Arch Surg 1988;123: Londrey GL, Ramsey DE, Hodgson KJ, Barkmeier LD, Sumner DS. Infrapopliteal bypass for severe ischemia: comparison of autogenous vein, composite and prosthetic grafts. J VAsc SURG 1991;13: Submitted June 10, 1993; accepted Dec. 20, DISCUSSION Dr. Robert P. Leather (Albany, N.Y.). The use of tibial arteries as an inflow source is the ultimate extension of a concept that these authors presented some years ago using inflow sources, when available, at the lowest level. The patency and salvage rates that have been produced by this are quite comparable to the use of proximal inflow sources. Our own experience is very limited. In fact, it's in the range of 1%. Nineteen of 2151 vein bypasses in the lower extremity used a tibial inflow source. It's a comparable population and has produced virtually identical results at 1 and 3 years. Therefore I agree that this is a very viable option, given these very special circumstances, that is, segmental tibial occlusion, insufficient autogenous vein to use the more proximal inflow source, and tissue necrosis. Are your results with these tibiotibial bypasses comparable to similar bypasses but using a more proximal inflow source such as the popliteal or distal superficial femoral artery? Does the choice of tibia] inflow represent a reluctance to splice vein segments to gain sufficient length for a more proximal inflow source? Dr. Ross Lyon. With regards to reluctance to splice

9 Volume 20, Number I Lyon et al. 69 vein segments together, yes, I believe there is a reluctance, and many of these patients would have required something on that sort if a longer bypass were to be done, and therefore we chose to do tibiotibial bypasses in these cases rather than several intervening anastomoses. As far as more proximal inflow sites, I believe the patency rates are comparable to using not only the femoral artery but also the distal superficial femoral and popliteal sources. There are now three studies out showing relatively long-term results with popliteal artery origin bypasses, and all the bypass patency results are about in the same range. And I believe that as with other series, bypass patency is largely dependent on the quality of vein conduit, and that is one of the things that has led us to develop use of progressively more distal sites for originating bypasses. LIEBIG FOUNDATION AWARD FOR VASCULAR SURGICAL RESEARCH, 1995 The Liebig Foundation announces the fourteenth annual competitive award of $10,000 for the best essay on a problem in general vascular surgery. The investigative work shall be 1. Clinical or experimental research 2. Original and unpublished (nor submitted elsewhere for publication) 3. Performed by a house officer in the United States, Canada, or Mexico, with senior collaborators acting in a consultive capacity 4. Submitted in English (6 copies of typed manuscript and 6 copies of glossy prints of illustrations) 5. Accompanied by a signed letter from the essayist's superior attesting that the essayist performed all the essential parts of the experimental work reported and complying with "Instructions to Authors" of the JOURNAL OF VASCULAR SURGERY and including an abstract of less than one page in length. The submitted manuscripts will be evaluated by a select committee of vascular surgeons. The manuscript judged best will be submitted to the Program Committee of the Southern Association for Vascular Surgery for consideration for inclusion on its 1995 scientific program and publication in the JOURNAL OF VASCULAR SURGERY. Further inquiries may be directed to the same address to which the essays must be sent, postmarked no later than August 15, 1994: Jean Goggins, PhD Award Committee Secretary 112 Bauer Drive Oakland, NJ USA (201)