Simulation case rehearsals for carotid artery stenting.

A case series of 5 patients is presented assessing the utility of simulation case rehearsals of individual patients for carotid artery stenting on an endovascular simulator. Simulated and operative device dimensions were similar. Results of subjective surveys indicated that face and content validity were excellent. The simulations predicted difficulty with vessel cannulation, however had difficulty predicting post-stent changes in bifurcation angulation. Our experience suggests that it may be feasible to use patient-specific CTA-derived data in the creation of a realistic case rehearsal simulation. The overall utility of this concept, including cost-benefit analysis, has yet to be determined.

Developmental changes in odor-evoked activity in rat piriform cortex.

In adult rats, odor-evoked Fos protein expression is found in rostrocaudally-oriented bands of cells in anterior piriform cortex (APC), likely indicating functionally distinct subregions, while activated cells in posterior piriform cortex (PPC) lack apparent spatial organization. To determine whether these patterns are present during early postnatal life, and whether they change during development, Fos expression was assessed following acute exposure to single aliphatic acid odors in developing rats beginning at postnatal day 3 (P3). In the olfactory bulb, Fos-immunoreactive cells were present in the granule cell, mitral cell and glomerular layers at the earliest ages examined. Cells immunopositive for Fos were clustered in areas previously reported as active in response to these odors. In piriform cortex, activation in layers II/III shared some features with that seen in the adult; in APC, rostro-caudally oriented bands of Fos-positive cells alternated with bands relatively free of label, while labeled cells were found dispersed throughout PPC. However, in P3-P7 animals, Fos-positive cells in APC were found in a central rostro-caudally oriented band that was flanked by two bands relatively free of Fos-positive cells. This contrasted with the adult pattern, a central cell-poor band flanked by cell-rich bands, which was observed beginning at P10. These results suggest that subregions of APC visualized by odor-evoked Fos expression are active and functionally distinct shortly after birth. Changes in activity within these subregions during early postnatal development coincide with a shift toward adult-like olfactory learning behavior in the second postnatal week, and may play a role in this behavioral shift.

Diagnosis and management of the "difficult" abdominal aortic aneurysm: pararenal aneurysms, inflammatory aneurysms, and horseshoe kidney.

All "difficult" abdominal aortic aneurysms-whether pararenal or inflammatory or associated with abnormal renal parenchymal anatomy-often best are approached with some combination of retroperitoneal exposure and supraceliac clamping. Preoperative recognition that an unusual case may exist, complete and appropriate imaging and formulation of a sensible plan before operation are absolutely critical to success. Following such a plan can convert a relatively complex situation into a relatively simple one.

Safety and efficacy of limited-dose tissue plasminogen activator in acute vascular occlusion.

OBJECTIVE: The purposes of this study were to evaluate the safety and efficacy of limited-dose tissue plasminogen activator (t-PA) in patients with acute vascular occlusion and to compare these results with those obtained in equivalent patients receiving urokinase. METHODS: We compared the results of 60 patients receiving catheter-directed urokinase from November 1997 to November 1998 (240,000 units/h x 4 h, 120,000 units/h thereafter for a maximum of 48 h) with those of 45 patients receiving catheter-directed t-PA from November 1998 to August 2000 (2 mg/h, total dose < or =100 mg) for acute arterial occlusion (AAO) and acute venous occlusion (AVO). Interventional approaches such as cross-catheter and coaxial techniques were used to reduce the dose of lytic agent needed to achieve pre-lysis-treatment goals (eg, complete lysis of all thrombus/unmasking graft stenosis or establishing outflow target). Statistical analysis was performed using Student t test and Fisher exact test. RESULTS: The urokinase and t-PA groups were comparable with regard to age, comorbidities (coronary artery disease, hypertension, diabetes, renal insufficiency, smoking), duration of ischemic or occlusive symptoms, location of occlusive process, pretreatment with warfarin, and thrombotic versus embolic and native versus graft occlusion in patients with AAO. In patients with AAO and in those with AVO, t-PA was equivalent to or better than urokinase with regard to percent of clot lysis, incidence of major bleeding complications, limb salvage, and mortality. Achievement of pretreatment goals (arterial patients only) was 50% for urokinase patients and 76% for t-PA patients (P =.02). Analysis of success in individual pretreatment-goal achievement showed urokinase and t-PA to be equivalent in unmasking stenoses (85% and 84%, respectively; P = NS), whereas t-PA was superior to urokinase in the more critical task of establishing run-off (39% versus 81% for urokinase and t-PA, respectively; P =.001). Additional interventions, either endovascular or surgical, were required in 60% and 51% (P = NS) of patients receiving urokinase and t-PA, respectively, for AAO, and in 54% and 62% (P = NS) of patients receiving urokinase and t-PA, respectively, for AVO. CONCLUSIONS: Limited-dose t-PA is a safe and effective therapy for AAO and AVO when administered by experienced teams using innovative but well-established interventional techniques.

External beam irradiation for inhibition of intimal hyperplasia following prosthetic bypass: preliminary results.

To determine whether external beam irradiation delivered immediately after graft implantation can inhibit anastomotic intimal hyperplasia (IH) 1 month following polytetrafluoroethylene (PTFE) bypass in a sheep carotid artery model, 23 sheep underwent bilateral bypass of the ligated common carotid artery with 8-mm PTFE immediately followed by a single dose of irradiation (15, 21, or 30 Gy) to one side. The 15 animals with bilaterally patent grafts were euthanized at 1 month and graft-arterial anastomoses harvested. Using computer-aided image analysis, IH areas and thicknesses were measured. Graft patency in this model was 83% at 1 month and did not differ according to treatment administered. In the control animals, IH was greatest at mid-anastomosis, but minimal within the native vessel. All three radiation doses markedly inhibited mid-anastomotic IH area and thickness. At the proximal anastomosis, 30 Gy reduced the IH area 20-fold, from 2.06 to 0.14 mm2 (p < 0.0001 by ANOVA), and IH thickness 70-fold, from 29.0 to 0.4 micron (p < 0.0002); similar effects were seen at the distal anastomosis. No adverse effects of radiation treatment were observed. External beam irradiation in doses of 15 to 30 Gy delivered in a single fraction immediately after operation markedly inhibits development of intimal hyperplasia 1 month following end-to-side anastomosis with PTFE in sheep.

Alcohol withdrawal after open aortic surgery.

This study was designed to test the hypothesis that unexpected alcohol withdrawal-like syndrome (AWLS) is more common following aortic, but not other, vascular or nonvascular procedures. All patients undergoing open aortic surgery at our institution in 1997 who survived at least 48 hr were identified, as were those undergoing carotid endarterectomy, infrainguinal bypass, and total colectomy. AWLS was defined as prolonged confusion or agitation and response to conventional treatment for withdrawal, providing that all other sources had been ruled out or a significant history was present. Our results show that, for unknown reasons, AWLS is more common after aortic surgery than after other vascular and high-stress, nonaortic intraabdominal procedures at our institution, and is associated with increased length of stay and morbidity. Because prophylaxis may improve outcome, better efforts to identify patients at risk are required.

Reperfusion and compartment syndromes: strategies for prevention and treatment.

Reperfusion syndrome refers to the damage done by restoration of blood flow to ischemic tissues and is distinct from the original ischemic insult itself, whereas compartment syndrome refers to the damage resulting from increased pressure within an enclosed fascial compartment that occurs after blood flow has been restored. Despite extensive experimental work directed toward the treatment of established reperfusion injury and prevention of compartment syndrome, clinical outcome over the past decade has not appreciably changed. Although the systemic insult, thought to be an inevitable result of reperfusion injury, may be less injurious than "conventional wisdom" would suggest, no better strategy for treating compartment syndrome other than early recognition and decompression has yet been developed.

Immunocytochemical analysis of basket cells in rat piriform cortex.

Basket cells, defined by axons that preferentially contact cell bodies, were studied in rat piriform (olfactory) cortex with antisera to gamma-aminobutyric acid (GABA)ergic markers (GABA, glutamate decarboxylase) and to peptides and calcium binding proteins that are expressed by basket cells. Detailed visualization of dendritic and axonal arbors was obtained by silver-gold enhancement of staining for vasoactive intestinal peptide (VIP), cholecystokinin (CCK), parvalbumin, and calbindin. Neuronal features were placed into five categories: soma-dendritic and axonal morphologies, laminar distributions of dendritic and axonal processes, and molecular phenotype. Although comparatively few forms were distinguished within each category, a highly varied co-expression of features from different categories produced a "combinatorial explosion" in the characteristics of individual neurons. Findings of particular functional interest include: dendritic distributions suggesting that somatic inhibition is mediated by feedforward as well as feedback pathways, axonal variations suggesting a differential shaping of the temporal aspects of somatic inhibition from different basket cells, evidence that different principal cell populations receive input from different combinations of basket cells, and a close association between axonal morphology and molecular phenotype. A finding of practical importance is that light microscopic measurements of boutons were diagnostic for the molecular phenotype and certain morphological attributes of basket cells. It is argued that the diversity in basket cell form in the piriform cortex, as in other areas of the cerebral cortex, reflects requirements for large numbers of specifically tailored inhibitory processes for optimal operation that cannot be met by a small number of rigidly defined neuronal populations.

Reduction in wound morbidity rates following endoscopic saphenous vein harvest.

To determine whether less-invasive saphenous vein harvest reduces morbidity in patients undergoing infrainguinal bypass, we retrospectively compared 61 patients undergoing endoscopic harvest (ENDO) with 49 patients undergoing conventional harvest (OPEN) over the past 13 months. Patients were classified as potential short-stay if adjunctive suprainguinal inflow procedures or foot amputations were not required and the patient was ambulatory prior to elective operation. Mean endoscopic harvest time was 50+/-18 (range 25-90) min, and no more than three 5-cm incisions were required in 87% of cases. Szilagyi class II or III wound complications occurred after 1 of the 61 (2%) ENDO procedures and 7 of the 49 (14%) OPEN (p < 0.01), and any complication occurred in 13 (21%) vs. 25 (51%) of ENDO and OPEN procedures, respectively (p < 0.002). Mean postoperative length of stay was significantly shorter in the 24 short-stay ENDO (4.0+/-2.4 days) vs. 25 short-stay OPEN (6.0+/-3.2 days) patients (p < 0.02). Thirty-day patency rates between the two groups were not different. Endoscopic saphenous vein harvest is associated with a reduced incidence of serious wound complications and, in selected patients, shortened postoperative hospital stay.

Combined free tissue transfer and infrainguinal bypass graft: an alternative to major amputation in selected patients.

OBJECTIVES: The purpose of this study was to document outcome and adverse prognostic factors in patients requiring combined free tissue transfer and distal bypass grafting for otherwise nonreconstructible infrainguinal arterial occlusive disease and advanced tissue necrosis. METHODS: Between July 1990 and November 1999, 65 patients, all of whom would have required at least below-knee amputation, underwent free tissue transfer in conjunction with infrainguinal bypass grafting at the University of Rochester. Preoperative variables were assessed for their influence on outcome with chi(2) and outcome with life-table analysis with Cox proportionate hazard testing. RESULTS: Free tissue transfer was performed synchronously with arterial reconstruction with autologous vein in 49 patients and after a previous functioning venous bypass graft in 16 patients. The 30-day mortality rate was 5%, and major complications occurred in another 16% of patients. Flap location, weight-bearing status, preexisting osteomyelitis, and the timing of bypass grafting relative to flap construction had no effect on outcome. All five free flap failures occurred within the first 30 days. All other flaps subsequently survived, even in seven patients whose bypass grafts thrombosed. Five-year limb salvage and patient survival rates were 57% and 60%, respectively, and 65% of patients regained meaningful ambulation. The combination of diabetes and dialysis-dependent renal failure was the strongest predictor of overall limb loss (P <.005; relative risk = 4.0), and diabetes alone was the strongest predictor of death (P <.02; relative risk = 5.2). CONCLUSION: Free tissue transfer combined with infrainguinal bypass grafting in selected patients is safe and effective. The combination of diabetes and chronic renal insufficiency, particularly the need for dialysis, is a powerful predictor of failure and should be considered a strong contraindication for this procedure.

Unrecognized carotid artery stenosis discovered by calcifications on a panoramic radiograph.

BACKGROUND: Approximately 730,000 strokes occur each year in the United States, costing an estimated $40 billion annually. One-half of all strokes are the result of atherosclerotic plaques found in the carotid artery. Such plaques frequently are heavily calcified and can be identified on a panoramic radiograph by the incidental finding of calcifications overlying the carotid bifurcation. CASE DESCRIPTION: The authors found that a 67-year-old asymptomatic woman had calcium deposits overlying both carotid bifurcation regions on a panoramic radiograph. Subsequent duplex ultrasonic examination indicated bilateral, high-grade carotid arterial stenoses. The patient underwent uneventful bilateral carotid endarterectomy. CLINICAL IMPLICATIONS: The patient had critical carotid arterial stenoses associated with significant risk of stroke that had not been identified otherwise. The findings on the panoramic radiograph led to appropriate and potentially life-saving treatment. While the positive predictive value of this finding has yet to be defined, the authors believe that calcifications overlying the carotid system region seen on panoramic radiography in an asymptomatic patient should be followed by formal evaluation of the carotid bifurcation.

Eversion endarterectomy of the carotid artery: technical considerations and recurrent stenoses.

PURPOSE: The purpose of this study was to examine the characteristics of residual and recurrent lesions after eversion endarterectomy of the carotid artery (E-CE) and compare these results with those following endarterectomy and patch closure (CE-P). METHODS: We reviewed 274 patients who underwent carotid endarterectomy in 1998 with electroencephalographic monitoring, general anesthesia, completion duplex scan, and 1-year follow-up. CE-P was preferred for patients who required temporary shunting. In the E-CE group an additional proximal 2-cm arteriotomy was made in the common carotid artery (CCA) in 79 patients, a longer arteriotomy was made for extensive involvement of the CCA in 14 patients, and the internal carotid artery was advanced proximally as a patch for the CCA arteriotomy closure in 14 patients. Stenoses of > 50% that were present at 1 month were considered residual, and those of > 50% that were present at 1 year but not at 1 month were considered recurrent. RESULTS: There were five (1.8%) postoperative strokes (four after CE-P and one after E-CE, P = not significant). At 30 days there were 28 patients (10.2%) with residual stenoses > 50% (11 patients [10.2%] in the E-CE group and 17 patients [10.1%] in the CE-P group; P = not significant). The incidence of recurrent lesions of more than 50% was similar (4.6% for E-CE vs 4.7% for CE-P). CONCLUSION: The pattern of residual lesions and recurrent stenoses differs with each technique of endarterectomy. Proximal stenoses are more common after E-CE, and distal stenoses are more common after CE-P at both 1 month and 1 year. The frequency of proximal lesions is reduced in E-CE when either the internal carotid artery is advanced proximally onto the CCA or a long CCA arteriotomy is made. Distal recurrences do not seem to be a problem after eversion endarterectomy.

Functional plasticity in extrastriate visual cortex following neonatal visual cortex damage and monocular enucleation.

Neonatal lesions of primary visual cortex (areas 17, 18 and 19; VC) in cats lead to significant changes in the organization of visual pathways, including severe retrograde degeneration of retinal ganglion cells of the X/beta class. Cells in posteromedial lateral suprasylvian (PMLS) cortex display plasticity in that they develop normal receptive-field properties despite these changes, but they do not acquire the response properties of striate neurons that were damaged (e.g., high spatial-frequency tuning, low contrast threshold). One possibility is that the loss of X-pathway information, which is thought to underlie striate cortical properties in normal animals, precludes the acquisition of these responses by cells in remaining brain areas following neonatal VC damage. Previously, we have shown that monocular enucleation at the time of VC lesion prevents the X-/beta-cell loss in the remaining eye. The purpose of the present study was to determine whether this sparing of retinal X-cells leads to the development of striate-like response properties in PMLS cortex. We recorded the responses of PMLS neurons to visual stimuli to assess spatial-frequency tuning, spatial resolution, and contrast threshold. Results indicated that some PMLS cells in animals with a neonatal VC lesion and monocular enucleation displayed a preference for higher spatial frequencies, had higher spatial resolution, and had lower contrast thresholds than PMLS cells in cats with VC lesion alone. Taken together, these results suggest that preserving X-pathway input during this critical period leads to the addition of some X-like properties to PMLS visual responses.

New features of connectivity in piriform cortex visualized by intracellular injection of pyramidal cells suggest that "primary" olfactory cortex functions like "association" cortex in other sensory systems.

Associational connections of pyramidal cells in rat posterior piriform cortex were studied by direct visualization of axons stained by intracellular injection in vivo. The results revealed that individual cells have widespread axonal arbors that extend over nearly the full length of the cerebral hemisphere. Within piriform cortex these arbors are highly distributed with no regularly arranged patchy concentrations like those associated with the columnar organization in other primary sensory areas (i.e., where periodically arranged sets of cells have common response properties, inputs, and outputs). A lack of columnar organization was also indicated by a marked disparity in the intrinsic projection patterns of neighboring injected cells. Analysis of axonal branching patterns, bouton distributions, and dendritic arbors suggested that each pyramidal cell makes a small number of synaptic contacts on a large number (>1000) of other cells in piriform cortex at disparate locations. Axons from individual pyramidal cells also arborize extensively within many neighboring cortical areas, most of which send strong projections back to piriform cortex. These include areas involved in high-order functions in prefrontal, amygdaloid, entorhinal, and perirhinal cortex, to which there are few projections from other primary sensory areas. Our results suggest that piriform cortex performs correlative functions analogous to those in association areas of neocortex rather than those typical of primary sensory areas with which it has been traditionally classed. Findings from other studies suggest that the olfactory bulb subserves functions performed by primary areas in other sensory systems.

Pharmacokinetics and hepatic disposition of bis[1-(ethoxycarbonyl)propyl]5-acetylamino-2,4,6-triiodoisophthalate in rats and isolated perfused rat livers.

Bis[1-(Ethoxycarbonyl)propyl]5-acetylamino-2,4,6- triiodoisophthalate+ (NC 68183) was designed as a new computed tomography imaging agent. The purpose of this study was to determine the pharmacokinetics and metabolism of NC 68183 in conscious rats and in the isolated perfused rat liver. Animals were i.v. dosed at 69 and 690 mg of iodine/kg. Blood samples were collected at 5, 15, 30, and 60 min, and 7 days after dosing. Tissue samples (liver, kidney, and spleen) were taken at 60 min and 7 days after dosing. NC 68183 was cleared from blood in first order kinetics following an i.v. administration of 69 mg I/kg. The volume of distribution (Vss) at steady state and elimination half-life (t(1/2)) were estimated as 24 ml and 11 min. The clearance of NC 68183 from blood was changed to zero-order kinetics following administration of 690 mg/kg, and its elimination rate was 16 microg I/ml.min. The liver and spleen were the only tissues to have the nanoparticle residue at day 7 following administration. NC 68183 (75 mg of agent, 35 mg of I) was injected into the isolated perfused rat liver system. Bile flow increased from 1.0 to 1.3 microl/min/g liver following administration. The biliary excretion rate maximum was estimated as 11 microg/min/g liver. The metabolite was identified using liquid chromatography/mass spectrometry as a monocarboxylic acid product, which exclusively excreted into the bile in a soluble iodinated metabolite. Pharmacokinetics data suggested that NC 68183 primarily resides in the blood pool following an i.v. administration with a plasma half-life appropriate for blood pool imaging.

An endoluminal method of hemorrhage control and repair of ruptured abdominal aortic aneurysms.

PURPOSE: To report our initial experience with endovascular grafting to treat ruptured abdominal aortic aneurysms (AAAs). METHODS: Three consecutive patients with severe comorbid illnesses and symptoms of aneurysm rupture and hemodynamic instability were treated with aortomonoiliac grafts. The Z-stent-based devices were implanted with the assistance of an occlusion balloon placed in the distal descending thoracic aorta. RESULTS: All patients survived the procedure with successfully excluded AAAs. Two patients had relatively short hospital stays (4 and 14 days), while the third required prolonged treatment for pre-existing conditions. All patients required blood transfusions; 2 developed significant coagulopathies. Definitive management was delayed significantly by imaging protocols and graft construction. CONCLUSIONS: Endovascular repair of ruptured aortic aneurysms is feasible. Proximal aortic control is readily attainable with the use of an aortic occlusion balloon placed through the left axillary artery. The absence of a laparotomy, extensive retroperitoneal dissection, and aortic cross-clamping likely contributes to patient survival; however, the delay in operative therapy to obtain adequate imaging and construct an endograft could be a hindrance to the ultimate success of this approach. The concepts of alternative aortic imaging techniques and endograft design, construction, and storage must be addressed.

Irradiation for intimal hyperplasia: implications for peripheral arterial bypass.

Irradiation has been shown to inhibit postangioplasty intimal hyperplasia ("restenosis") in unbranched tubes. It seems likely that irradiation will similarly be able to inhibit intimal hyperplasia after a surgical anastomosis at a biochemical and cellular level, but whether it will produce a clinically relevant or even clinically detectable difference is unproved. One possibility is that no clinical effect may occur; the search for a "cure" for intimal hyperplasia has been long and, as yet, unsuccessful. On the other hand, if a strong effect without insurmountable logistical problems could be produced, one major cause of bypass graft failure would be preventable. Not only would the incidence of late graft occlusion, need for reoperation, and limb loss be reduced, but, if patency of prosthetics could be sufficiently improved, the initial operation could be made much easier, faster, and perhaps safer.

Mechanical versus chemical thrombolysis: an in vitro differentiation of thrombolytic mechanisms.

PURPOSE: To assess differing mechanisms of thrombolysis determining time to reperfusion, completeness of thrombus dissolution, and embolic potential. MATERIALS AND METHODS: An in vitro perfusion model designed to mimic arterial flow conditions was created. Bifurcated limbs allowed continuous flow through one channel and the placement of radiolabeled (iodine-125) thrombus housed in a 5-cm segment of polytetrafluoroethylene graft in the other. The three experimental groups consisted of a standard continuous urokinase infusion, a pulsed pressurized injection of saline, and a similar injection with urokinase. A continuous infusion of 5% dextrose served as a control group. Time to reflow (as assessed with ultrasonic flow monitoring), completeness of thrombus dissolution (I-125 liberated into solution), and the number and size of embolic particles produced (detected by a series of graduated filter sizes) were analyzed. RESULTS: Time to reflow was significantly faster for both groups when pressurized injections were used (P < .001). There was no reflow in the control arm at 90 minutes. Completeness of thrombus dissolution was higher when a continuous infusion of urokinase was used in comparison to either of the power injection groups or the control (P < .05). The amount of embolic debris produced was significantly lower with a continuous infusion of urokinase compared with either of the power lysis groups (P < .05), but significantly greater than the control arm (P < .001). The size of the embolic particles in the power pulsed lysis groups was significantly decreased by the addition of urokinase (P < .05). CONCLUSIONS: Reflow is more rapidly established by the use of mechanical means. However, a less complete dissolution of thrombus in conjunction with a greater amount of embolic debris is achieved with this approach. The size of the embolic particles produced is reduced by the addition of a thrombolytic agent.

Time course of nodal enhancement with CT X-ray nanoparticle contrast agents: effect of particle size and chemical structure.

RATIONALE AND OBJECTIVES: Levels of CT enhancement in rabbit lymph nodes were followed with time after subcutaneous injection of four iodinated, insoluble nanoparticle contrast agents to provide experimental support for the hypothesis that clearance of these agents is related to the chemical structure of the agent itself. The impact of particle size was also studied. METHODS: Subcutaneous injections (2 x 0.25 mL) were made in the dorsum of rabbit paws with 15% suspensions of four nanoparticle contrast agents. Images were obtained at 4, 10, 24, 48, and 72 hours and 5, 7, and 14 days after injection. Average attenuation (in Hounsfield units [HU]), node volume, and total iodine uptake were estimated from the CT scans for each lymph node at each time point. RESULTS: All the agents provided adequate enhancement of both the popliteal and axillary lymph nodes of the rabbit (ie, > delta100 HU). Lymph node volume appears to be related to the persistence of enhancement, with long-lived agents demonstrating the greatest increase in size. The rate of clearance from the lymph nodes is related to the structure of the agent. CONCLUSIONS: Clearance of insoluble, iodinated nanoparticle contrast agents from lymph nodes can be modulated by changes in the structure of the agent itself. Using the same agent, smaller particles deliver material to the lymph nodes more quickly and clear more quickly.

Photoplethysmography and calf muscle pump function after subfascial endoscopic perforator ligation.

OBJECTIVE: Subfascial endoscopic perforator surgery (SEPS) results in acceptable healing and recurrence rates. The role of hemodynamic venous testing in this situation, however, is poorly understood and inconsistently used. Our ongoing experience was reviewed to explore how SEPS affects the photoplethysmographic assessment of the leg. METHODS: Preoperative and postoperative venous refill times (VRTs) were measured with photoplethysmography in 30 limbs in 28 patients who underwent SEPS and superficial ablation, when indicated, with complete clearing of the anterolateral surface of the tibia, thus opening the deep posterior compartment from mid calf to close to the malleolus. Postoperative healing and duplex scanning were used to assess clinical and anatomic success, respectively. The VRTs were classified as "interpretable" if the leg emptied or "uninterpretable" if the calf could not empty. The "interpretable" study results were further classified as "normal" if the refill took 20 seconds or more or "abnormal" if less. RESULTS: Before the patients underwent SEPS, six study results (20%) showed inability of the calf to empty and thus were judged uninterpretable. After the patients underwent SEPS, 12 study results (40%) were uninterpretable (NS; P =.09 with the chi(2) test). Of the 24 preoperative interpretable study results, two (8%) were normal, and of the 18 postoperative interpretable study results, seven (39%) were normal (P <.03). With the consideration of only interpretable study results, the mean VRT increased slightly from 12.0 +/- 5.1 seconds (mean +/- standard deviation) to 14.3 +/- 8.1 seconds (NS). Seventeen of 19 ulcers (89%) had healed at a mean follow-up period of 8.6 +/- 4.8 months. CONCLUSION: Although VRT is unpredictably affected by SEPS, the most consistent finding is the inability of the calf to empty, which invalidates the remainder of the test. In addition, most ulcers heal, even with uninterpretable or abnormal postoperative VRTs. This suggests that photoplethysmography is a poor method of assessment of venous reflux after SEPS.