Ronnie Landis - Academia.edu (original) (raw)
Papers by Ronnie Landis
Annals of vascular surgery, 1995
To determine whether the choice of material used for patch closure following carotid artery endar... more To determine whether the choice of material used for patch closure following carotid artery endarterectomy (CAE) affected the immediate operative results, the early follow-up results, or the incidence of early restenosis, a retrospective study of 275 consecutive carotid endarterectomies by two vascular surgeons was performed. Among 275 primary CAEs performed between July 1991 and August 1993, 159 (57.8%) were closed with saphenous vein (SV), 25 (9.1%) with double-thickness internal jugular vein (JV), and 91 (33.1%) with knitted Dacron (KD). Primary closure was not used in any of the arteries in this series. The overall perioperative mortality rate was 1.1% and the rate of major and minor morbidity was 4.4% There were four (1.5%) perioperative strokes: two (1.3%) in the SV group, one (4.0%) in the JV group, and one (1.1%) in the KD group. Two-hundred fifty-eight (93.8%) of the 275 endarterectomies were followed postoperatively for 2 to 35 months (mean 14.4). Two-hundred nineteen (79....
European Journal of Vascular Surgery, 1991
From a registry of 2406 carotid endarterectomies performed on 1818 patients over a 19-year period... more From a registry of 2406 carotid endarterectomies performed on 1818 patients over a 19-year period, 29 patients (1.6%) underwent reoperations for recurrent stenosis. Reoperations were performed for symptomatic stenosis for 23 and asymptomatic greater than 80% stenosis for six patients. Compared to the entire series, there was no difference in the incidence of restenosis for men and women. The pathologic findings were myointimal hyperplasia in 27%, atherosclerosis in 53%, thrombus with vessel dilatation in 17% and extrinsic scar in 3%. Redo endarterectomy with patch angioplasty was used for reconstruction in 27 patients and patch angioplasty alone in two. There were no operative deaths or strokes. Late follow-up (mean 50 months) revealed only one stroke and six other deaths. Although 21 (75%) were alive and stroke-free, follow-up studies suggest a high incidence (21%) of tertiary lesions among patients who have undergone redo endarterectomy for recurrent stenosis.
Annals of vascular surgery, 2002
The natural history and clinical significance of type II or branch vessel endoleaks following end... more The natural history and clinical significance of type II or branch vessel endoleaks following endovascular aortic aneurysm (AAA) repair remain unclear. Some investigators have suggested that these endoleaks have a benign course and outcome and that they can be safely observed. The purpose of this study was to document the natural history and outcome of all type II endoleaks that have occurred following endovascular AAA repair at our institution. A review of a prospectively compiled database of all endovascular AAA repairs performed at our institution was performed. From this review, we determined that type II endoleaks appear to have a relatively benign course, with a reasonable chance of spontaneously sealing within a 2-year period. No cases of rupture or aneurysm enlargement were documented in patients with open type II leaks. However, almost one-third of the patients did not manifest a type II leak until after their initial CT scan. The implications of such a "delayed" ...
Annals of Vascular Surgery, 1998
It has been suggested that general anesthesia is the preferred method for reoperative carotid sur... more It has been suggested that general anesthesia is the preferred method for reoperative carotid surgery for several reasons, including: the difficulty of the reoperative dissection; the disease may extend unusually high into the internal carotid artery; and the reconstruction required may be more complex than a typical endarterectomy. The purpose of this study is to show that reoperative carotid surgery can be performed safely under regional anesthesia. The records of 109 reoperative carotid operations performed on 96 patients over the past 25 years were reviewed. Procedures performed under regional anesthesia were compared to those performed under general anesthesia with respect to patient characteristics, intraoperative courses, and perioperative results. Regional anesthesia was utilized in 79 operations (72.5%); 30 operations were performed with general anesthesia (27.5%). The two patient groups were essentially equivalent with regard to atherosclerotic risk factors, preoperative neurologic symptoms, and the prevalence of contralateral total occlusion. The etiologies for recurrent disease included recurrent atherosclerosis (50.4%), intimal hyperplasia (30.3%), and vein patch aneurysm (9.2%). The methods of reconstruction employed included saphenous vein patch (47.7%), vein interposition graft (11.9%), prosthetic patch (20.2%), and prosthetic graft (20.2%). Perioperative strokes occurred in one case performed under regional anesthesia (1.3%), and in two cases under general anesthesia (6.6%); this difference was not statistically significant. Reoperative carotid artery surgery can be performed under regional anesthesia safely in the majority of instances. The aforementioned theoretical factors in favor of general anesthesia could also lead to technical difficulties with intraarterial shunt insertion. Having the patient awake, even if just long enough to prove that the patient will tolerate carotid artery clamping, might simplify many of these operations by avoiding shunt insertion. Regional anesthesia should therefore be considered an acceptable option in cases of reoperative carotid surgery.
Annals of Vascular Surgery, 1999
The purpose of this study was to review a single-institution experience with the Endovascular Tec... more The purpose of this study was to review a single-institution experience with the Endovascular Technologies [(EVT) Menlo Park, CA] transfemoral, endovascular system of abdominal aortic aneurysm repair. This study was performed at a medical center participating in the phase 1 and phase 2 evaluations of the EVT device. We reviewed the 25 cases performed at our institution. The patient population consisted of 21 males (84%) and 4 females (16%), with a mean age of 73.4 years. A total of eight tube grafts (32%) and 17 bifurcated grafts (68%) were attempted. Twenty-two of the twenty-five grafts were successfully implanted endovascularly (88%). Implantation failures were due to tortuosity or inadequate caliber of the iliac arteries, or incorrect positioning of the graft. The results show that endovascular repair of abdominal aortic aneurysms is an appropriate treatment for selected patients. Conversions to open repair have decreased as experience has grown; careful patient selection can minimize the number of unsuccessful implantations. Patient selection and accurate technique can also minimize the number of endoleaks.
Annals of Vascular Surgery, 1997
Patients who have sustained a preoperative stroke are at increased risk for perioperative stroke ... more Patients who have sustained a preoperative stroke are at increased risk for perioperative stroke after carotid endarterectomy. At our institution this risk was recently shown to be increased two-to threefold. The purpose of this study was to investigate the reasons for the increased surgical risk in these patients. Records of 606 patients undergoing 704 consecutive carotid endarterectomies from 1988 through 1993 were reviewed. Patients who suffered preoperative strokes (n = 183) were compared to those who were either asymptomatic or experienced only transient ischemic attacks (TIAs) preoperatively (n = 423). Of the 183 patients who had suffered preoperative strokes, eight patients who experienced perioperative strokes after endarterectomy were compared with 175 who successfully underwent surgery. Patients with a prior stroke had an increased perioperative stroke rate (4.4% versus 1.2%, p = 0.01). They had a significantly higher incidence of hypertension (62.6% versus 47.9%, p < 0.001), cardiac disease (54.7% versus 40.7%, p = 0.001), and positive smoking history (52% versus 40.6%, p = 0.01) than did the asymptomatic/TIA patients. The presence of contralateral total occlusion was also significantly increased (22% versus 10.3%, p < 0.001). Although not statistically significant due to the overall small number of patients who sustained perioperative strokes, the preoperative stroke patients who sustained perioperative strokes had a higher incidence of hypertension (87.5% versus 61.5%) and contralateral total occlusion (37.5% versus 21.3%) than did those who successfully underwent surgery. Patients with both a prior stroke and contralateral total occlusion had a 7.5% perioperative stroke rate. Patients with both a prior stroke and hypertension had a 6.1% perioperative stroke rate. The perioperative strokes in patients with prior strokes were not related to the severity of the prior stroke, the interval between the stroke and surgery, the use of a shunt, or the type of anesthesia employed. Patients who have sustained preoperative strokes have a higher incidence of significant medical illnesses and overall cerebrovascular disease. Hypertension and total occlusion of the contralateral carotid artery appear to be particularly poor prognostic indicators of outcome after endarterectomy in these patients. Patients who have sustained preoperative strokes may be more likely to display clinical neurologic symptoms in response to any form of cerebral ischemia. In this higher risk subgroup, intraoperative and surgeon-dependent factors appear to play less of a role.
Annals of Vascular Surgery, 2003
Proponents of carotid angioplasty and stenting (CAS) believe that this technique would be preferr... more Proponents of carotid angioplasty and stenting (CAS) believe that this technique would be preferred over carotid endarterectomy (CEA) for the high-risk patient. Presumably this would include patients over 80 years of age. However, a recent large series of patients undergoing CAS revealed a 16% incidence of nonfatal strokes and deaths for patients over the age of 80; these results were significantly worse than those for younger patients undergoing CAS. The objective of this study was to reassess results of CEA in patients over 80, and to compare surgical results with the published results of CAS in this patient group. A review was conducted of a prospectively maintained database of all carotid surgery performed at our institution. Primary CEA that took place from 1997 through 1999 were included for analysis (n = 698). Our institutional results were compared with representative results from a recently published large series of CAS. Our analysis showed that CEA can be performed safely in the octogenarian, and results are equivalent to those of younger patients. CEA appears to have significantly better results in the octogenarian than CAS. The reasons for the poor outcomes of CAS in the octogenarian are unclear. The results of CAS in the older patient population are worrisome, and this ''less invasive'' technique may prove to be an inferior alternative in this patient group.
Annals of Vascular Surgery, 2001
Annals of Vascular Surgery, 2002
Since the Food and Drug Administrations' approval of endovascular devices for abdominal aortic an... more Since the Food and Drug Administrations' approval of endovascular devices for abdominal aortic aneurysm (AAA) repair, clinicians have been relaxing the strict inclusion criteria present during the clinical trials. Although the long-term natural history of endoleaks remains unclear, attachment site leaks (type I) are believed to represent an ongoing risk for future rupture. We reviewed our experience with endovascular AAA repair to elucidate factors that predispose toward the development of endoleaks and found that larger AAAs are signi®cantly more likely to have a short proximal neck and severe proximal angulation. These factors likely contribute to the sig-ni®cantly increased rate of type I endoleaks that occurred after endovascular repair of large AAAs. Small AAAs (<5) had the lowest rate of endoleaks overall (8.3%) and of type I endoleaks in particular (0%). We conclude that AAA size and morphology can be used to predict which aneurysms will experience attachment site endoleaks in their course; AAAs from 4.5 to 5 cm in diameter may be particularly well suited for endovascular repair in this regard. 2 644
Annals of Vascular Surgery, 2004
Citing the higher perioperative risk of redo carotid surgery, balloon angioplasty and stenting of... more Citing the higher perioperative risk of redo carotid surgery, balloon angioplasty and stenting of the carotid artery (CAS) has been advocated for recurrent carotid stenosis (RCS). To examine the impact of CAS on the management and outcome of recurrent stenosis, a retrospective review of a prospectively compiled database was performed. From a registry of patients treated for carotid disease, 105 procedures were performed from 1992 to 2002 for RCS. For comparison, two study groups were examined. Time I consisted of 77 reoperations performed through 1998, before CAS was introduced at our institution. Time II included 12 reoperations and 16 CAS procedures performed for RCS from 1999 through 2002. Using perioperative stroke as a measure of outcome, the results for time II were poorer than for time I (7.2% vs. 5.2%, p = NS). Overall, the risk of perioperative stroke was the same for reoperation (5/89) and CAS (1/16) (5.6% vs. 6.3%, p = NS). Although not statistically significant, there was a trend toward a higher risk of perioperative stroke for patients treated with reoperation during the latter time period (8.3% vs. 5.2%, p = NS). This probably relates to the finding that during time II, CAS was most likely to be used in asymptomatic patients (68.6% vs. 41.7%, p = NS) with early (<3 years) RCS (87.5% vs. 41.7%, p = 0.01). No patient with asymptomatic, early RCS had a perioperative stroke with either surgery or CAS (0/35 cases, 0%). The presence of preoperative neurologic symptoms was significantly predictive of a perioperative stroke among all procedures performed for RCS (13.6% vs. 0%, p = 0.004). Contrary to suggestions that CAS might improve the management of RCS, a review of our data shows the overall risk of periprocedural stroke to be no better since CAS has become available. The bias for using CAS for asymptomatic myointimal hyperplastic lesions, and reoperation for frequently symptomatic late recurrent atherosclerotic disease, makes direct comparisons of the two techniques for treating RCS difficult. It is expected that the overall risk for redo carotid surgery will increase, as fewer low-risk patients will be receiving open procedures. However, the increased risk among symptomatic patients undergoing reoperation suggests that endovascular techniques should be investigated among this group of cases as well.
Annals of Vascular Surgery, 2001
To determine whether choice of material used for patch closure following carotid artery endartere... more To determine whether choice of material used for patch closure following carotid artery endarterectomy (CAE) influences rates of early or late restenosis, stroke, and death, 274 consecutive CAEs were retrospectively reviewed. Saphenous vein (SV) was used in 159 (58.0%) procedures; everted, double-thickness jugular vein (JV) was used in 25 (9.1%); and knitted Dacron (KD) was used in 90 (32.9%). Primary closure was not used in this series. There were four perioperative strokes: two (1.3%) in SV, one (4%) in JV, and one (1.1%) in KD (NS). Follow-up was obtained on 263 (96%) operated arteries (mean 41.5 months). Duplex scan results were available for 236 (89.7%) of these arteries (mean follow-up time 33.7 months). There were three (2%) late strokes in SV and two (2.2%) in KD (NS). In long-term follow-up, one patient (0.7%) in SV and two (2.4%) in KD developed > 80% stenosis (NS). One patient (0.7%) in SV, one (5.3%) in JV, and one (1.2%) in KD had total occlusion of the operated vessel (NS). Three procedures (2.2%) in SV, 1 (5.3%) in JV, and 7 (8.5%) in KD demonstrated moderate stenosis (50-79%) (NS). Three-year follow-up shows that choice of patch material does not affect early or late stroke rate, stroke-related death rate, rate of high-grade (> 80%) restenosis, or rate of total occlusion. There is a higher incidence of moderate stenosis in KD. Although our results and a review of the literature do not indicate that these patients are at increased risk for symptoms or progression of stenosis, they should be followed by duplex scanning to ensure that this is the case.
Annals of Vascular Surgery, 2001
In order to maximize the efficacy of carotid endarterectomy (CEA), the rate of perioperative stro... more In order to maximize the efficacy of carotid endarterectomy (CEA), the rate of perioperative stroke must be kept to a minimum. A recent analysis of carotid surgery at our institution found that most perioperative strokes were due to technical errors resulting in thrombosis or embolization. From 1992 through 1997 we have performed nearly 1200 additional CEAs; the purpose of this study was to examine recent trends in the causes of perioperative stroke, with specific attention to differences in symptomatic and asymptomatic patients. The records of 1041 patients undergoing 1165 CEAs were reviewed from a prospectively compiled database. Analysis of these data showed that a history of preoperative stroke appears to increase the risk of perioperative stroke after CEA. Surgical factors associated with perioperative stroke include an inability to tolerate clamping, use of an intraarterial shunt, and having surgery performed under general anesthesia; these factors are clearly interrelated and only the use of intraarterial shunting remains a risk factor by multivariate analysis. Over half of all perioperative strokes (54%) appear to be caused by intraoperative or postoperative thrombosis and embolization. The patient requiring use of intraarterial shunting and/or with a preoperative stroke most likely has a significant watershed area of brain at increased risk of infarction. However, technical errors are still the most common cause of perioperative stroke in these high-risk patients. Such high-risk patients may manifest clinical stroke from small emboli that may be tolerated by asymptomatic clamptolerant patients. Technical precision and appropriate cerebral protection are particularly critical for successful outcomes in high-risk patients.
Cardiovascular Surgery, 1995
Recent data from the North American Symptomatic Carotid Endarterectomy Trial revealed a 14.3% per... more Recent data from the North American Symptomatic Carotid Endarterectomy Trial revealed a 14.3% perioperative risk of stroke or death with carotid endarterectomy contralateral to a carotid artery occlusion. Since last reporting on this topic in the mid-1980s, the authors have reviewed 180 patients with occlusion of one internal carotid artery (ICA) and who underwent endarterectomy of the stenotic contralateral ICA operated from 1965 to 1984 (group A) compared with 135 operated on from 1985 to 1991. The two groups were similar with respect to age, sex, incidence of coronary artery disease, hypertension, diabetes and history of smoking, but group B had a significantly increased incidence of patients who were neurologically symptom-free before surgery (21.5% versus 7.8%, P < 0.001). The combined perioperative stroke or death rate for patients in group B was significantly lower than for those in group A (0.7% versus 6.7%, P < 0.01). Comparison of the operative techniques showed more frequent placement of intra-arterial shunt (52.6% versus 29.4%, P < 0.001) and increased use of general anesthesia (20.0% versus 9.4%, P < 0.01) in patients of group B. Analysis of the etiology of the complications, however, showed that shunting alone could not account for the improved results. Lower incidences of postoperative thrombosis, embolization and intracerebral hemorrhage were equally important.(ABSTRACT TRUNCATED AT 250 WORDS)
Radiology, 2005
To retrospectively determine the natural history of type II endoleaks detected at thin-section mu... more To retrospectively determine the natural history of type II endoleaks detected at thin-section multi-detector row computed tomographic (CT) angiography. Neither institutional review board approval nor patient informed consent was required. Between December 1999 and December 2000, 83 patients (73 men and 10 women; mean age, 61 years; range, 55-75 years) underwent endovascular repair of an infrarenal abdominal aortic aneurysm with an endoluminal stent graft. Postprocedural abdominal CT angiography was performed every 3-12 months for the evaluation of endoleaks and the maximal sac diameter. A retrospective analysis of all postprocedural CT angiographic reports was performed until November 2003 to document the presence and development of type II endoleaks and the maximal orthogonal aneurysmal sac size. Findings at CT angiography were evaluated with regard to clinical outcomes and treatment in all patients in whom type II endoleaks were observed. The postprocedural follow-up period was 1.5-4.5 years (mean, 2.5 years). Twenty type II endoleaks were identified in 16 (19%) of the 83 patients. Four (20%) of the 20 endoleaks were embolized secondary to an increasing aneurysmal sac size when compared with that at preoperative CT angiography. These four leaks occurred in two patients, each with two separate endoleaks. Sixteen (80%) of the 20 endoleaks in 14 patients were managed with continued observation. In these patients, the aneurysmal sac size was stable or had decreased when compared with the size at preoperative CT angiography. Ten (62.5%) of the 16 endoleaks have sealed spontaneously during the follow-up, and six (37.5%) have persisted with stable or decreased aneurysmal sac size. None of the patients experienced aneurysmal sac rupture. Type II endoleaks with a stable or decreased aneurysmal sac size can be followed up with CT angiography secondary to the high rate of spontaneous resolution and a low risk of rupture.
Journal of Vascular Surgery, 2000
Purpose: When managing a new neurologic deficit after carotid endarterectomy (CEA), the surgeon i... more Purpose: When managing a new neurologic deficit after carotid endarterectomy (CEA), the surgeon is often preoccupied with determining the cause of the problem, requesting diagnostics tests, and deciding whether the patient should be surgically reexplored. The goal of this study was to analyze a series of perioperative neurologic events and to determine if careful analysis of their timing and mechanisms can predict which cases are likely to improve with reoperation. Methods: A review of 2024 CEAs performed from 1985 to 1997 revealed 38 patients who manifested a neurologic deficit in the perioperative period (1.9%). These cases form the focus of this analysis. Results: The causes of the events included intraoperative clamping ischemia in 5 patients (13.2%); thromboembolic events in 24 (63.2%); intracerebral hemorrhage in 5 (13.2%); and deficits unrelated to the operated artery in 4 (10.5%). Neurologic events manifesting in the first 24 hours after surgery were significantly more likely to be caused by thromboembolic events than by other causes of stroke (88.0% vs 12.0%, P < .002); deficits manifesting after the first 24 hours were significantly more likely to be related to other causes. Of 25 deficits manifesting in the first 24 hours after surgery, 18 underwent immediate surgical reexploration. Intraluminal thrombus was noted in 15 of the 18 reexplorations (83.3%); any technical defects were corrected. After the 18 reexplorations, in 12 cases there was either complete resolution of or significant improvement in the neurologic deficit that had been present (66.7%). Conclusions: Careful analysis of the timing and presentation of perioperative neurologic events after CEA can predict which cases are likely to improve with reoperation. Neurologic deficits that present during the first 24 hours after CEA are likely to be related to intraluminal thrombus formation and embolization. Unless another etiology for stroke has clearly been established, we think immediate reexploration of the artery without other confirmatory tests is mandatory to remove the embolic source and correct any technical problems. This will likely improve the neurologic outcome in these patients, because an uncorrected situation would lead to continued embolization and compromise
Journal of Vascular Surgery, 2001
Objectives: Although the results of the Asymptomatic Carotid Atherosclerosis Study clearly demons... more Objectives: Although the results of the Asymptomatic Carotid Atherosclerosis Study clearly demonstrated the benefit of surgical over medical management of severe carotid artery stenosis, the results for women in particular were less certain. This was to some extent because of the higher perioperative complication rate observed in the 281 women (3.6% vs 1.7% in men). The objective of this study was to review a large experience with carotid endarterectomy in female patients and to determine whether the perioperative results differed from those of male patients. Methods: A review was conducted of a prospectively compiled database on all carotid endarterectomies performed between 1982 and 1997. Operations performed in 991 female patients were compared with those performed in 1485 male patients. Results: Female patients had a significantly lower incidence of diabetes, coronary artery disease, and contralateral carotid artery occlusion than did male patients. Female patients had a significantly higher incidence of hypertension. There were no significant differences in the age, smoking history, anesthetic route, shunt use, or clamp tolerance between the two groups. Of 991 female patients, 659 (66.5%) had preoperative symptoms, whereas 332 (33.5%) cases were performed for asymptomatic stenosis. Among 1485 male patients, 1041 (70.1%) had symptoms, and 444 (29.9%) were symptom free before surgery. There were no significant differences noted in the perioperative stroke rates between men and women overall (2.3% vs 2.4%, P = .92), or when divided into symptomatic (2.5% vs 3.0%, P = .52) and asymptomatic (2.0% vs 1.2%, P = .55) cases. Conclusions: Carotid endarterectomy can be performed with equally low perioperative stroke rates in men and women in both symptomatic and asymptomatic cases. In this series, symptom-free female patients had the lowest overall stroke rate. The concerns of the Asymptomatic Carotid Atherosclerosis Study regarding the benefit of carotid endarterectomy in female patients should therefore not prevent clinicians from recommending and performing carotid endarterectomy in appropriately selected symptom-free female patients. (J Vasc Surg 2001;33:236-41.)
Journal of Vascular Surgery, 2001
excision of a T4 meningioma. Recent gait unsteadiness had led to a magnetic resonance imaging (MR... more excision of a T4 meningioma. Recent gait unsteadiness had led to a magnetic resonance imaging (MRI) of the spine, which revealed a pseudomeningocele at the site of the earlier operation. It was concluded with neurosurgical evaluation that this was likely the cause of his gait disturbance. Neurosurgical intervention was planned, but this was deferred until the AAA was addressed.
Journal of Vascular Surgery, 2003
Journal of Vascular Surgery, 1997
Natural history and management of the asymptomatic, moderately stenotic internal carotid artery C... more Natural history and management of the asymptomatic, moderately stenotic internal carotid artery C a r o n B. R o c k m a n , M D , T h o m a s S. Riles, M D , Patrick J. L a m p a r e l l o , M D , G a r y Giangola, M D , M a r k A. A d e l m a n , M D , D a v i d Stone, BA, C l a u d i o Guareschi, M D , J o n a t h a n Goldstein, BA, and R o n n i e Landis, R N , New York, N.Y.
Annals of vascular surgery, 1995
To determine whether the choice of material used for patch closure following carotid artery endar... more To determine whether the choice of material used for patch closure following carotid artery endarterectomy (CAE) affected the immediate operative results, the early follow-up results, or the incidence of early restenosis, a retrospective study of 275 consecutive carotid endarterectomies by two vascular surgeons was performed. Among 275 primary CAEs performed between July 1991 and August 1993, 159 (57.8%) were closed with saphenous vein (SV), 25 (9.1%) with double-thickness internal jugular vein (JV), and 91 (33.1%) with knitted Dacron (KD). Primary closure was not used in any of the arteries in this series. The overall perioperative mortality rate was 1.1% and the rate of major and minor morbidity was 4.4% There were four (1.5%) perioperative strokes: two (1.3%) in the SV group, one (4.0%) in the JV group, and one (1.1%) in the KD group. Two-hundred fifty-eight (93.8%) of the 275 endarterectomies were followed postoperatively for 2 to 35 months (mean 14.4). Two-hundred nineteen (79....
European Journal of Vascular Surgery, 1991
From a registry of 2406 carotid endarterectomies performed on 1818 patients over a 19-year period... more From a registry of 2406 carotid endarterectomies performed on 1818 patients over a 19-year period, 29 patients (1.6%) underwent reoperations for recurrent stenosis. Reoperations were performed for symptomatic stenosis for 23 and asymptomatic greater than 80% stenosis for six patients. Compared to the entire series, there was no difference in the incidence of restenosis for men and women. The pathologic findings were myointimal hyperplasia in 27%, atherosclerosis in 53%, thrombus with vessel dilatation in 17% and extrinsic scar in 3%. Redo endarterectomy with patch angioplasty was used for reconstruction in 27 patients and patch angioplasty alone in two. There were no operative deaths or strokes. Late follow-up (mean 50 months) revealed only one stroke and six other deaths. Although 21 (75%) were alive and stroke-free, follow-up studies suggest a high incidence (21%) of tertiary lesions among patients who have undergone redo endarterectomy for recurrent stenosis.
Annals of vascular surgery, 2002
The natural history and clinical significance of type II or branch vessel endoleaks following end... more The natural history and clinical significance of type II or branch vessel endoleaks following endovascular aortic aneurysm (AAA) repair remain unclear. Some investigators have suggested that these endoleaks have a benign course and outcome and that they can be safely observed. The purpose of this study was to document the natural history and outcome of all type II endoleaks that have occurred following endovascular AAA repair at our institution. A review of a prospectively compiled database of all endovascular AAA repairs performed at our institution was performed. From this review, we determined that type II endoleaks appear to have a relatively benign course, with a reasonable chance of spontaneously sealing within a 2-year period. No cases of rupture or aneurysm enlargement were documented in patients with open type II leaks. However, almost one-third of the patients did not manifest a type II leak until after their initial CT scan. The implications of such a "delayed" ...
Annals of Vascular Surgery, 1998
It has been suggested that general anesthesia is the preferred method for reoperative carotid sur... more It has been suggested that general anesthesia is the preferred method for reoperative carotid surgery for several reasons, including: the difficulty of the reoperative dissection; the disease may extend unusually high into the internal carotid artery; and the reconstruction required may be more complex than a typical endarterectomy. The purpose of this study is to show that reoperative carotid surgery can be performed safely under regional anesthesia. The records of 109 reoperative carotid operations performed on 96 patients over the past 25 years were reviewed. Procedures performed under regional anesthesia were compared to those performed under general anesthesia with respect to patient characteristics, intraoperative courses, and perioperative results. Regional anesthesia was utilized in 79 operations (72.5%); 30 operations were performed with general anesthesia (27.5%). The two patient groups were essentially equivalent with regard to atherosclerotic risk factors, preoperative neurologic symptoms, and the prevalence of contralateral total occlusion. The etiologies for recurrent disease included recurrent atherosclerosis (50.4%), intimal hyperplasia (30.3%), and vein patch aneurysm (9.2%). The methods of reconstruction employed included saphenous vein patch (47.7%), vein interposition graft (11.9%), prosthetic patch (20.2%), and prosthetic graft (20.2%). Perioperative strokes occurred in one case performed under regional anesthesia (1.3%), and in two cases under general anesthesia (6.6%); this difference was not statistically significant. Reoperative carotid artery surgery can be performed under regional anesthesia safely in the majority of instances. The aforementioned theoretical factors in favor of general anesthesia could also lead to technical difficulties with intraarterial shunt insertion. Having the patient awake, even if just long enough to prove that the patient will tolerate carotid artery clamping, might simplify many of these operations by avoiding shunt insertion. Regional anesthesia should therefore be considered an acceptable option in cases of reoperative carotid surgery.
Annals of Vascular Surgery, 1999
The purpose of this study was to review a single-institution experience with the Endovascular Tec... more The purpose of this study was to review a single-institution experience with the Endovascular Technologies [(EVT) Menlo Park, CA] transfemoral, endovascular system of abdominal aortic aneurysm repair. This study was performed at a medical center participating in the phase 1 and phase 2 evaluations of the EVT device. We reviewed the 25 cases performed at our institution. The patient population consisted of 21 males (84%) and 4 females (16%), with a mean age of 73.4 years. A total of eight tube grafts (32%) and 17 bifurcated grafts (68%) were attempted. Twenty-two of the twenty-five grafts were successfully implanted endovascularly (88%). Implantation failures were due to tortuosity or inadequate caliber of the iliac arteries, or incorrect positioning of the graft. The results show that endovascular repair of abdominal aortic aneurysms is an appropriate treatment for selected patients. Conversions to open repair have decreased as experience has grown; careful patient selection can minimize the number of unsuccessful implantations. Patient selection and accurate technique can also minimize the number of endoleaks.
Annals of Vascular Surgery, 1997
Patients who have sustained a preoperative stroke are at increased risk for perioperative stroke ... more Patients who have sustained a preoperative stroke are at increased risk for perioperative stroke after carotid endarterectomy. At our institution this risk was recently shown to be increased two-to threefold. The purpose of this study was to investigate the reasons for the increased surgical risk in these patients. Records of 606 patients undergoing 704 consecutive carotid endarterectomies from 1988 through 1993 were reviewed. Patients who suffered preoperative strokes (n = 183) were compared to those who were either asymptomatic or experienced only transient ischemic attacks (TIAs) preoperatively (n = 423). Of the 183 patients who had suffered preoperative strokes, eight patients who experienced perioperative strokes after endarterectomy were compared with 175 who successfully underwent surgery. Patients with a prior stroke had an increased perioperative stroke rate (4.4% versus 1.2%, p = 0.01). They had a significantly higher incidence of hypertension (62.6% versus 47.9%, p < 0.001), cardiac disease (54.7% versus 40.7%, p = 0.001), and positive smoking history (52% versus 40.6%, p = 0.01) than did the asymptomatic/TIA patients. The presence of contralateral total occlusion was also significantly increased (22% versus 10.3%, p < 0.001). Although not statistically significant due to the overall small number of patients who sustained perioperative strokes, the preoperative stroke patients who sustained perioperative strokes had a higher incidence of hypertension (87.5% versus 61.5%) and contralateral total occlusion (37.5% versus 21.3%) than did those who successfully underwent surgery. Patients with both a prior stroke and contralateral total occlusion had a 7.5% perioperative stroke rate. Patients with both a prior stroke and hypertension had a 6.1% perioperative stroke rate. The perioperative strokes in patients with prior strokes were not related to the severity of the prior stroke, the interval between the stroke and surgery, the use of a shunt, or the type of anesthesia employed. Patients who have sustained preoperative strokes have a higher incidence of significant medical illnesses and overall cerebrovascular disease. Hypertension and total occlusion of the contralateral carotid artery appear to be particularly poor prognostic indicators of outcome after endarterectomy in these patients. Patients who have sustained preoperative strokes may be more likely to display clinical neurologic symptoms in response to any form of cerebral ischemia. In this higher risk subgroup, intraoperative and surgeon-dependent factors appear to play less of a role.
Annals of Vascular Surgery, 2003
Proponents of carotid angioplasty and stenting (CAS) believe that this technique would be preferr... more Proponents of carotid angioplasty and stenting (CAS) believe that this technique would be preferred over carotid endarterectomy (CEA) for the high-risk patient. Presumably this would include patients over 80 years of age. However, a recent large series of patients undergoing CAS revealed a 16% incidence of nonfatal strokes and deaths for patients over the age of 80; these results were significantly worse than those for younger patients undergoing CAS. The objective of this study was to reassess results of CEA in patients over 80, and to compare surgical results with the published results of CAS in this patient group. A review was conducted of a prospectively maintained database of all carotid surgery performed at our institution. Primary CEA that took place from 1997 through 1999 were included for analysis (n = 698). Our institutional results were compared with representative results from a recently published large series of CAS. Our analysis showed that CEA can be performed safely in the octogenarian, and results are equivalent to those of younger patients. CEA appears to have significantly better results in the octogenarian than CAS. The reasons for the poor outcomes of CAS in the octogenarian are unclear. The results of CAS in the older patient population are worrisome, and this ''less invasive'' technique may prove to be an inferior alternative in this patient group.
Annals of Vascular Surgery, 2001
Annals of Vascular Surgery, 2002
Since the Food and Drug Administrations' approval of endovascular devices for abdominal aortic an... more Since the Food and Drug Administrations' approval of endovascular devices for abdominal aortic aneurysm (AAA) repair, clinicians have been relaxing the strict inclusion criteria present during the clinical trials. Although the long-term natural history of endoleaks remains unclear, attachment site leaks (type I) are believed to represent an ongoing risk for future rupture. We reviewed our experience with endovascular AAA repair to elucidate factors that predispose toward the development of endoleaks and found that larger AAAs are signi®cantly more likely to have a short proximal neck and severe proximal angulation. These factors likely contribute to the sig-ni®cantly increased rate of type I endoleaks that occurred after endovascular repair of large AAAs. Small AAAs (<5) had the lowest rate of endoleaks overall (8.3%) and of type I endoleaks in particular (0%). We conclude that AAA size and morphology can be used to predict which aneurysms will experience attachment site endoleaks in their course; AAAs from 4.5 to 5 cm in diameter may be particularly well suited for endovascular repair in this regard. 2 644
Annals of Vascular Surgery, 2004
Citing the higher perioperative risk of redo carotid surgery, balloon angioplasty and stenting of... more Citing the higher perioperative risk of redo carotid surgery, balloon angioplasty and stenting of the carotid artery (CAS) has been advocated for recurrent carotid stenosis (RCS). To examine the impact of CAS on the management and outcome of recurrent stenosis, a retrospective review of a prospectively compiled database was performed. From a registry of patients treated for carotid disease, 105 procedures were performed from 1992 to 2002 for RCS. For comparison, two study groups were examined. Time I consisted of 77 reoperations performed through 1998, before CAS was introduced at our institution. Time II included 12 reoperations and 16 CAS procedures performed for RCS from 1999 through 2002. Using perioperative stroke as a measure of outcome, the results for time II were poorer than for time I (7.2% vs. 5.2%, p = NS). Overall, the risk of perioperative stroke was the same for reoperation (5/89) and CAS (1/16) (5.6% vs. 6.3%, p = NS). Although not statistically significant, there was a trend toward a higher risk of perioperative stroke for patients treated with reoperation during the latter time period (8.3% vs. 5.2%, p = NS). This probably relates to the finding that during time II, CAS was most likely to be used in asymptomatic patients (68.6% vs. 41.7%, p = NS) with early (<3 years) RCS (87.5% vs. 41.7%, p = 0.01). No patient with asymptomatic, early RCS had a perioperative stroke with either surgery or CAS (0/35 cases, 0%). The presence of preoperative neurologic symptoms was significantly predictive of a perioperative stroke among all procedures performed for RCS (13.6% vs. 0%, p = 0.004). Contrary to suggestions that CAS might improve the management of RCS, a review of our data shows the overall risk of periprocedural stroke to be no better since CAS has become available. The bias for using CAS for asymptomatic myointimal hyperplastic lesions, and reoperation for frequently symptomatic late recurrent atherosclerotic disease, makes direct comparisons of the two techniques for treating RCS difficult. It is expected that the overall risk for redo carotid surgery will increase, as fewer low-risk patients will be receiving open procedures. However, the increased risk among symptomatic patients undergoing reoperation suggests that endovascular techniques should be investigated among this group of cases as well.
Annals of Vascular Surgery, 2001
To determine whether choice of material used for patch closure following carotid artery endartere... more To determine whether choice of material used for patch closure following carotid artery endarterectomy (CAE) influences rates of early or late restenosis, stroke, and death, 274 consecutive CAEs were retrospectively reviewed. Saphenous vein (SV) was used in 159 (58.0%) procedures; everted, double-thickness jugular vein (JV) was used in 25 (9.1%); and knitted Dacron (KD) was used in 90 (32.9%). Primary closure was not used in this series. There were four perioperative strokes: two (1.3%) in SV, one (4%) in JV, and one (1.1%) in KD (NS). Follow-up was obtained on 263 (96%) operated arteries (mean 41.5 months). Duplex scan results were available for 236 (89.7%) of these arteries (mean follow-up time 33.7 months). There were three (2%) late strokes in SV and two (2.2%) in KD (NS). In long-term follow-up, one patient (0.7%) in SV and two (2.4%) in KD developed > 80% stenosis (NS). One patient (0.7%) in SV, one (5.3%) in JV, and one (1.2%) in KD had total occlusion of the operated vessel (NS). Three procedures (2.2%) in SV, 1 (5.3%) in JV, and 7 (8.5%) in KD demonstrated moderate stenosis (50-79%) (NS). Three-year follow-up shows that choice of patch material does not affect early or late stroke rate, stroke-related death rate, rate of high-grade (> 80%) restenosis, or rate of total occlusion. There is a higher incidence of moderate stenosis in KD. Although our results and a review of the literature do not indicate that these patients are at increased risk for symptoms or progression of stenosis, they should be followed by duplex scanning to ensure that this is the case.
Annals of Vascular Surgery, 2001
In order to maximize the efficacy of carotid endarterectomy (CEA), the rate of perioperative stro... more In order to maximize the efficacy of carotid endarterectomy (CEA), the rate of perioperative stroke must be kept to a minimum. A recent analysis of carotid surgery at our institution found that most perioperative strokes were due to technical errors resulting in thrombosis or embolization. From 1992 through 1997 we have performed nearly 1200 additional CEAs; the purpose of this study was to examine recent trends in the causes of perioperative stroke, with specific attention to differences in symptomatic and asymptomatic patients. The records of 1041 patients undergoing 1165 CEAs were reviewed from a prospectively compiled database. Analysis of these data showed that a history of preoperative stroke appears to increase the risk of perioperative stroke after CEA. Surgical factors associated with perioperative stroke include an inability to tolerate clamping, use of an intraarterial shunt, and having surgery performed under general anesthesia; these factors are clearly interrelated and only the use of intraarterial shunting remains a risk factor by multivariate analysis. Over half of all perioperative strokes (54%) appear to be caused by intraoperative or postoperative thrombosis and embolization. The patient requiring use of intraarterial shunting and/or with a preoperative stroke most likely has a significant watershed area of brain at increased risk of infarction. However, technical errors are still the most common cause of perioperative stroke in these high-risk patients. Such high-risk patients may manifest clinical stroke from small emboli that may be tolerated by asymptomatic clamptolerant patients. Technical precision and appropriate cerebral protection are particularly critical for successful outcomes in high-risk patients.
Cardiovascular Surgery, 1995
Recent data from the North American Symptomatic Carotid Endarterectomy Trial revealed a 14.3% per... more Recent data from the North American Symptomatic Carotid Endarterectomy Trial revealed a 14.3% perioperative risk of stroke or death with carotid endarterectomy contralateral to a carotid artery occlusion. Since last reporting on this topic in the mid-1980s, the authors have reviewed 180 patients with occlusion of one internal carotid artery (ICA) and who underwent endarterectomy of the stenotic contralateral ICA operated from 1965 to 1984 (group A) compared with 135 operated on from 1985 to 1991. The two groups were similar with respect to age, sex, incidence of coronary artery disease, hypertension, diabetes and history of smoking, but group B had a significantly increased incidence of patients who were neurologically symptom-free before surgery (21.5% versus 7.8%, P < 0.001). The combined perioperative stroke or death rate for patients in group B was significantly lower than for those in group A (0.7% versus 6.7%, P < 0.01). Comparison of the operative techniques showed more frequent placement of intra-arterial shunt (52.6% versus 29.4%, P < 0.001) and increased use of general anesthesia (20.0% versus 9.4%, P < 0.01) in patients of group B. Analysis of the etiology of the complications, however, showed that shunting alone could not account for the improved results. Lower incidences of postoperative thrombosis, embolization and intracerebral hemorrhage were equally important.(ABSTRACT TRUNCATED AT 250 WORDS)
Radiology, 2005
To retrospectively determine the natural history of type II endoleaks detected at thin-section mu... more To retrospectively determine the natural history of type II endoleaks detected at thin-section multi-detector row computed tomographic (CT) angiography. Neither institutional review board approval nor patient informed consent was required. Between December 1999 and December 2000, 83 patients (73 men and 10 women; mean age, 61 years; range, 55-75 years) underwent endovascular repair of an infrarenal abdominal aortic aneurysm with an endoluminal stent graft. Postprocedural abdominal CT angiography was performed every 3-12 months for the evaluation of endoleaks and the maximal sac diameter. A retrospective analysis of all postprocedural CT angiographic reports was performed until November 2003 to document the presence and development of type II endoleaks and the maximal orthogonal aneurysmal sac size. Findings at CT angiography were evaluated with regard to clinical outcomes and treatment in all patients in whom type II endoleaks were observed. The postprocedural follow-up period was 1.5-4.5 years (mean, 2.5 years). Twenty type II endoleaks were identified in 16 (19%) of the 83 patients. Four (20%) of the 20 endoleaks were embolized secondary to an increasing aneurysmal sac size when compared with that at preoperative CT angiography. These four leaks occurred in two patients, each with two separate endoleaks. Sixteen (80%) of the 20 endoleaks in 14 patients were managed with continued observation. In these patients, the aneurysmal sac size was stable or had decreased when compared with the size at preoperative CT angiography. Ten (62.5%) of the 16 endoleaks have sealed spontaneously during the follow-up, and six (37.5%) have persisted with stable or decreased aneurysmal sac size. None of the patients experienced aneurysmal sac rupture. Type II endoleaks with a stable or decreased aneurysmal sac size can be followed up with CT angiography secondary to the high rate of spontaneous resolution and a low risk of rupture.
Journal of Vascular Surgery, 2000
Purpose: When managing a new neurologic deficit after carotid endarterectomy (CEA), the surgeon i... more Purpose: When managing a new neurologic deficit after carotid endarterectomy (CEA), the surgeon is often preoccupied with determining the cause of the problem, requesting diagnostics tests, and deciding whether the patient should be surgically reexplored. The goal of this study was to analyze a series of perioperative neurologic events and to determine if careful analysis of their timing and mechanisms can predict which cases are likely to improve with reoperation. Methods: A review of 2024 CEAs performed from 1985 to 1997 revealed 38 patients who manifested a neurologic deficit in the perioperative period (1.9%). These cases form the focus of this analysis. Results: The causes of the events included intraoperative clamping ischemia in 5 patients (13.2%); thromboembolic events in 24 (63.2%); intracerebral hemorrhage in 5 (13.2%); and deficits unrelated to the operated artery in 4 (10.5%). Neurologic events manifesting in the first 24 hours after surgery were significantly more likely to be caused by thromboembolic events than by other causes of stroke (88.0% vs 12.0%, P < .002); deficits manifesting after the first 24 hours were significantly more likely to be related to other causes. Of 25 deficits manifesting in the first 24 hours after surgery, 18 underwent immediate surgical reexploration. Intraluminal thrombus was noted in 15 of the 18 reexplorations (83.3%); any technical defects were corrected. After the 18 reexplorations, in 12 cases there was either complete resolution of or significant improvement in the neurologic deficit that had been present (66.7%). Conclusions: Careful analysis of the timing and presentation of perioperative neurologic events after CEA can predict which cases are likely to improve with reoperation. Neurologic deficits that present during the first 24 hours after CEA are likely to be related to intraluminal thrombus formation and embolization. Unless another etiology for stroke has clearly been established, we think immediate reexploration of the artery without other confirmatory tests is mandatory to remove the embolic source and correct any technical problems. This will likely improve the neurologic outcome in these patients, because an uncorrected situation would lead to continued embolization and compromise
Journal of Vascular Surgery, 2001
Objectives: Although the results of the Asymptomatic Carotid Atherosclerosis Study clearly demons... more Objectives: Although the results of the Asymptomatic Carotid Atherosclerosis Study clearly demonstrated the benefit of surgical over medical management of severe carotid artery stenosis, the results for women in particular were less certain. This was to some extent because of the higher perioperative complication rate observed in the 281 women (3.6% vs 1.7% in men). The objective of this study was to review a large experience with carotid endarterectomy in female patients and to determine whether the perioperative results differed from those of male patients. Methods: A review was conducted of a prospectively compiled database on all carotid endarterectomies performed between 1982 and 1997. Operations performed in 991 female patients were compared with those performed in 1485 male patients. Results: Female patients had a significantly lower incidence of diabetes, coronary artery disease, and contralateral carotid artery occlusion than did male patients. Female patients had a significantly higher incidence of hypertension. There were no significant differences in the age, smoking history, anesthetic route, shunt use, or clamp tolerance between the two groups. Of 991 female patients, 659 (66.5%) had preoperative symptoms, whereas 332 (33.5%) cases were performed for asymptomatic stenosis. Among 1485 male patients, 1041 (70.1%) had symptoms, and 444 (29.9%) were symptom free before surgery. There were no significant differences noted in the perioperative stroke rates between men and women overall (2.3% vs 2.4%, P = .92), or when divided into symptomatic (2.5% vs 3.0%, P = .52) and asymptomatic (2.0% vs 1.2%, P = .55) cases. Conclusions: Carotid endarterectomy can be performed with equally low perioperative stroke rates in men and women in both symptomatic and asymptomatic cases. In this series, symptom-free female patients had the lowest overall stroke rate. The concerns of the Asymptomatic Carotid Atherosclerosis Study regarding the benefit of carotid endarterectomy in female patients should therefore not prevent clinicians from recommending and performing carotid endarterectomy in appropriately selected symptom-free female patients. (J Vasc Surg 2001;33:236-41.)
Journal of Vascular Surgery, 2001
excision of a T4 meningioma. Recent gait unsteadiness had led to a magnetic resonance imaging (MR... more excision of a T4 meningioma. Recent gait unsteadiness had led to a magnetic resonance imaging (MRI) of the spine, which revealed a pseudomeningocele at the site of the earlier operation. It was concluded with neurosurgical evaluation that this was likely the cause of his gait disturbance. Neurosurgical intervention was planned, but this was deferred until the AAA was addressed.
Journal of Vascular Surgery, 2003
Journal of Vascular Surgery, 1997
Natural history and management of the asymptomatic, moderately stenotic internal carotid artery C... more Natural history and management of the asymptomatic, moderately stenotic internal carotid artery C a r o n B. R o c k m a n , M D , T h o m a s S. Riles, M D , Patrick J. L a m p a r e l l o , M D , G a r y Giangola, M D , M a r k A. A d e l m a n , M D , D a v i d Stone, BA, C l a u d i o Guareschi, M D , J o n a t h a n Goldstein, BA, and R o n n i e Landis, R N , New York, N.Y.