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LAPAROSCOPIC CHOLECYSTECTOMY: APPLICABILITY IN THE GERIATRIC POPULATION. T.H.Maqnuson, L.E.Ratner, M.E.Zenilman and J.S.Bender, Dept. of Surgery, Johns Hopkins Bayview Medical Center, Baltimore, MD

Elderly patients with cholelithiasis are more likely than non-elderly patients to present with an acute complication of gallstone disease such as acute cholecystiti s {AC), gallstone pancreatitis (GSP), or common bile duct stones (CBDS). These acute complications may make laparoscopic cholecystectomy (LC) more hazardous with a potential increase in perioperative morbidity or need for open conversion. The applicability of LC in the geriatric population is, therefore, unclear. We reviewed 301 consecutive patients undergoing cholecystectomy for symptomatic gallstone disease. LC was attempted in 283 patients (94%), 23% of whom were elderly (->65 years old). Patients were classified as presenting with complicated (comp = AC, GSP, or CBDS) or uncomplicated (uncomp) chronic gallstone disease. Elderly patients were significantly more likely than younger patients to present with AC (40% vs 19%), GSP (19% vs 6%), and CBDS (21% vs 5%); all p<0.05. In addition, the elderly were more likely to have required previous hospitalization for gallbladder disease (23% vs 3%) and present with advanced (gangrenous) cholecystitis (21 vs 5%) compared to non-elderly patients. Other results were:

ELDERLY NON-ELDERLY comP u ncomp total comp uncornp total

n = 42 20 62 62 159 221 Open conversion(%) 50 5 35* 16 7 9 Intraop morbidity(%) 12 0 8" 2 1 1 Overall morbidity(%) 21 10 18" 12 4 6 Hosp stay (days) 11.2 2.3 8.3* 5.9 2.0 3.0

*p < 0.05 compared to non-elderly group tntraop morbidity included bile duct, enteric, or major vascular injuries.

There was no mortality in either group. Overall, elderly patients were significantly more likely to require open conversion, have an intraoperative complication, and require a longer hospital stay. These differences were largely due to the high percentage of elderly patients presenting with complicated gallstone disease. Elderly patients with uncomplicated gallstone disease appear to be excellent candidates for LC and this should be considered before complicated disease develops. Conversely, early conversion or planned open cholecystectomy may be warranted in the elderly presenting with acute complications of cholelithiasis.

BRUSH BORDER NA*/H + EXCHANGE PLAYS A PREDOMINANT ROLE IN ILEAL ABSORPTION. M.M. Maher, J. Gontarek, R.E. Jimenez, M. Donowit z, C.J. Yeo, Depts. of Surgery and Medicine, Joh1%s Hopkins Medical Institutions, Baltimore, MD.

Na÷/H ÷ exchangers have been identified and cloned in mammalian intestine: NHE-I on the basolateral membrane, regulating intracellular pH; and NHE-3 on the brush border, serving transcellular absorption of Na ÷. NHE-I is much more sensitive to inhibition by amiloride than NHE-3, their Ki's for amiloride being I~M and 39~M, respectively. This study tested the hypothesis that brush border rather than basolateral Na÷/H ÷ exchange plays a major role in basal and meal-stimulated ileal absorption. METHODS: Absorption studies (n=72) were performed in dogs with 25 cm ileal Thiry-Vella fistulae. Six groups were studied over four hours. Perfusion with ~dC-PEG was used to calculate absorption of water, ions and glucose. Luminal amiloride was administered from the 2nd to the 4th hours (at doses of 20 ~M in groups 3 and 4 and 1 mM in groups 5 and 6) to inhibit basolateral and brush border Na*/H ÷ exchange, respectively. A 480 Kcal canine meal was ingested after the second hour in groups 2, 4, and 6. RESULTS: Amiloride (1 mM) caused significant reductions in basal and meal-stimulated ileal absorption, while the 20 #M dose had no effect:

TOTAL HOURLy ~SORPTION OF WATER(ml) GROI/~(n) IB 9 Hour 2nd Hour 3rd Hour 4th Hour i. Control (12) 19_+2 21_+2 19_+3 22_+2 2. M~al (12) 14±3 17~3 19-+2 30±3.-- I 3. AMIL 20 ~M (12] 19+_3 21±2 21_+3 23_+2 4. AMIL 20 ~M+Meal(12) 20±3 22t2 22_+3 32+_4* # 5. AMIL 1 mM (12) 20±3 15_+2 13_+2" 10±2" 6. AMIL 1 mM + Meal (12) 17_+2 12±2 11-+2 21+_4 • p <0.01 compared to Is~ hour; # p<0.01; Sodium absorption parallelled w~t~r -

CONCLUSIONS: These data are consistent with the hypothesis that amiloride-resistant brush border rather than amiloride-sensitive basolateral Na÷/H * exchange is predominant in basal and meal - stimulated ileal absorption.

• PANCREAS-SPARING DUODENECTOMY FOR INFRA-AMPULLARY DUODENAL PATHOLOGY. M.M. Mahera C.J.Ye0, K.D. Lillemoe, J.R. Roberts and J.L. Cameron. Dept. of Surgery, Johns Hopkins Med. Instit. Baltimore, MD.

Surgical management of distal duodenal pathology is challenging because of its retroperitoneal location and shared blood supply with the pancreas. For infra-ampullary pathology, surgical treatment may include local excision, pancreas-sparing duodenectomy(PSD) or pancreaticoduodenectomy. Methods: We retrospectively reviewed the management of 22 patients with infra-ampullary duodenal pathology treated by PSD between 1985 and 1994. Results: There were 15 males and 7 females with a mean age of 52.1±4.7 yrs. Indications for elective PSD included neoplasms (13), Crohn's disease(2) and other(2). Five patients had PSD as an emergency procedure for penetrating trauma. There were Ii malignant neoplasms (9 adenocarcinoma, ! lymphoma, 1 liposarcoma) and 2 benign lesions (i villous adenoma, 1 benign stromal tumor). Two of the ii patients with malignant lesions had palliative resection. The mean follow- up is 21.5±5.5 mo. (range 1-110 mo.). In the group undergoing elective PSD, the mean length of operation was 5.3±0.5 hr. and the estimated blood loss was 597±135 ml. There was one postoperative death (5%) from an anastomotic leak and one reexploration for anastomotic bleeding. The mean time to oral intake was 9.9±2 days. PSD in patients with trauma or benign duodenal pathology(ll) resulted in a good outcome in all. In those II patients with malignant disease, four have expired and four had recurrences, with £wo requiring reresection. Actuarial and disease free survival in patients with malignant disease were 57.3% and 27% at 2 years. Conclusions: PSD is a safe and effective treatment in patients with distal duodenal benign neoplasms or trauma. PSD has limited long-term effectiveness in cases of malignant distal duodenal pathology.

AN OBJECTIVE STRUCTURED ASSESSMENT OF TECHNICAL SKILL (OSATS) FOR SURGICAL RESIDENTS. J. Martin, G. Reqehr, R. Reznick, H. MacRae, M. Brown, J. Murnauhan, C. Hutchison. A. Lossing, M. Cusimano, R. Cohen, Surgical Education Research Group, Department of Surgery, University of Toronto. Toronto, Ontario.

Measurement of technical skill has been a weak link in the assessment of surgical residents' competence. We have developed two parallel objective tests of technical skill, one using a live animal model and one using simulations in a bench model. Two approaches to grading performance were used: an operation specific detailed checklist (DCL) and a general global rating form (GRF). The purpose of the study was: i) to compare the live and bench formats; 2) to compare the reliability of the DCL and GRF; and 3) to assess the construct validity of each examination by analyzing discrimination of residents at different levels of training, Twelve 15 minute operative tasks were administered to 20 residents. Performance was evaluated by 48 surgeons. Mean scores on the bench and live examination did not differ (p>.05). Mean inter-rater reliability across stations ranged from .641 to .743 for the two exam formats using the two scoring procedures. Internal consistency (Crohbach's alpha) was low for the bench DCL, but was moderate to high (.619 -.747) for the live DCL and the bench and live GRF. Further, the GRF showed significant differences between levels of residents for both the bench format (F(2,17)=4.45, p<.05) and the live format (F(2,17)=3.55,p=.05). A new approach to measuring technical competence can assess surgical skills in a reliable and valid way. The GRF was more psychometrically sound than the DCL. The bench format was equivalent to the use of live animals for this type of assessment.