Outpatient Versus Inpatient Anterior Lumbar Spine Surgery: A Multisite, Comparative Analysis of Patient Safety Measures.

BACKGROUND: The frequency and complexity of spinal surgery performed in an ambulatory surgery center (ASC) is increasing. However, safety and efficacy data of most spinal procedures adapted to the ASC are sparse and have focused on anterior cervical surgery. The purpose of this study was to compare the 90-day complication and readmission rates of anterior lumbar spine surgery performed in an ASC or inpatient setting. METHODS: We performed a retrospective comparative analysis of 226 consecutive anterior lumbar surgeries (283 levels treated) completed in an ASC (n = 124) or in an inpatient tertiary care hospital (n = 102) over a 3-year period. These included anterior lumbar interbody fusion (ALIF), artificial disc replacement (ADR), and hybrids. Patients undergoing simultaneous or staged posterior procedures within 3 months were excluded. Patient demographics and surgical parameters between the two surgical settings were compared. Ninety-day medical complications and readmission rates were assessed. One-way analysis of variance and Chi-square analysis were used. A P value of less than .05 was considered statistically significant. RESULTS: The two study groups had similar baseline characteristics. While there was a trend toward fewer complications, reoperations, and readmissions for the ASC cohort, the differences were not statistically significant. There were 7 intraoperative complications (5.6% minor vascular injury) in the inpatient cohort and 0 in the ASC cohort. The overall 90-day postoperative complication rate was 5.6% for the inpatient cohort and 0.9% for the ASC cohort. The 90-day readmission rate was 1.9% in the ASC cohort and 1.6% in the inpatient cohort. The 90-day reoperation rate was 0.8% for the inpatient cohort and 0% in the ASC cohort. The average hospital stay was 2.3 ± 1.5 days for the inpatient cohort. CONCLUSION: The 90-day readmission rates were lower for outpatients than for inpatients, while the complication and reoperation rates were similar. Our results demonstrate that anterior lumbar procedures, including single-level and multilevel ALIF, ADR, and hybrid procedures, can be performed safely in an ASC. This has significant cost savings implications for the ASC setting.

Lead-Specific Features Predisposing to the Development of Tricuspid Regurgitation After Endocardial Lead Implantation.

BACKGROUND: Endocardial lead in the right ventricle is recognized as a cause for tricuspid regurgitation (TR), but the mechanism remains elusive. We sought to evaluate lead-specific features on the development of TR after endocardial lead implantation. METHODS: This was a prospective single-center study. The patients underwent 2-dimensional echocardiograms before endocardial lead implantation and at follow-up visits at 4 to 6 weeks, 6 months, and 12 months. We assessed the position of the endocardial lead at the tricuspid annulus by 3-dimensional echocardiography, the tricuspid leaflet interference by the endocardial lead by both 2- and 3-dimensional echocardiography, and the degree of lead slack radiologically. Patient characteristics and lead-related factors were evaluated in the prediction of new or worse TR by univariable and multivariable analyses. RESULTS: New or increased TR was detected in 38 of 128 patients at the 12-month follow-up. The postero-septal commissure was the most common lead position, and tricuspid leaflet interference detected in 21 patients was associated with a noncommissural lead position. The implantation of an implantable cardioverter defibrillator lead was not associated with new TR compared with the implantation of a pacemaker lead. Tricuspid leaflet interference (P < 0.0001), but not lead position or lead slack, was the only lead-specific factor associated with the development of TR. CONCLUSION: After right ventricle endocardial lead implantation, leaflet interference determined by echocardiography, but not the nature of the lead, the lead position at the tricuspid annulus, and the radiological lead slack, predicted TR development at 1 year postimplantation.

CONTEXTE: Il est établi que la présence d'une sonde endocavitaire dans le ventricule droit est une cause de régurgitation tricuspide (RT), mais le mécanisme en cause n'est pas encore bien compris. Nous avons tenté d'évaluer la corrélation entre certaines caractéristiques des sondes et l'apparition d'une RT secondaire à l'implantation d'une sonde endocavitaire. MÉTHODOLOGIE: Il s'agit d'une étude prospective menée dans un seul centre. Une échocardiographie bidimensionnelle a été réalisée avant la mise en place d'une sonde endocavitaire, ainsi qu'aux visites de suivi menées 4 à 6 semaines, 6 mois et 12 mois après l'intervention. Nous avons évalué la position de la sonde endocavitaire par rapport à l'anneau tricuspidien par échocardiographie tridimensionnelle, l'interférence de la sonde avec la valve tricuspide par échocardiographie bidimensionnelle et tridimensionnelle, et le degré de liberté de mouvement de la sonde par radiographie. Les caractéristiques des patients et les facteurs liés à la sonde ont été pris en compte dans la prédiction du risque de RT nouvelle ou d'aggravation d'une RT existante au moyen d'analyses univariées et multivariées. RÉSULTATS: Une RT nouvelle ou aggravée a été détectée au suivi à 12 mois chez 38 des 128 patients. Dans la plupart des cas, la sonde se trouvait à la commissure postéroseptale; chez 21 patients, une interférence avec la valve tricuspide a été détectée alors que la sonde ne se trouvait pas à la commissure. La mise en place d'une sonde de défibrillateur implantable n'a pas été associée à l'apparition d'une RT, comparativement à l'implantation d'une sonde de stimulateur cardiaque. L'interférence avec la valve tricuspide (p < 0,0001) était le seul facteur lié à la sonde associé à l'apparition d'une RT; aucun lien n'a été établi avec la position et le degré de liberté de mouvement de la sonde. CONCLUSION: Après la mise en place d'une sonde endocavitaire dans le ventricule droit, l'interférence avec la valve tricuspide établie par échocardiographie permettait de prédire l'apparition d'une RT dans l'année suivant la mise en place de la sonde sans égard au type de sonde, à sa position par rapport à l'anneau tricuspidien ou à la liberté de mouvement détectée par radiographie.

The Influence of Collagen Impregnation of a Knitted Dacron Patch Used in Carotid Endarterectomy.

BACKGROUND: In selected populations, carotid endarterectomy (CEA) reduces long-term stroke risk. Studies have shown increased risk of restenosis with use of a collagen-impregnated Dacron patch compared to a polytetrafluorethylene patch. There is concern that collagen impregnation may initiate thrombosis or promote restenosis due to platelet activation. We performed a retrospective analysis of our CEA experience with routine patching using knitted Dacron patches with (Hemashield) and without (Sauvage) collagen impregnation. METHODS: Our database was queried for all CEAs between January 2006 and December 2010. Seven surgeons performed 655 CEAs. Patients were excluded if no patch was used (n = 1), a primary CEA was performed before study period or by other surgeons (n = 11), or the patch type was indeterminable (n = 38). Demographics, clinical data, and outcomes were compared between the collagen-impregnated (C, Hemashield) group and non-collagen-impregnated (NC, Sauvage) group. RESULTS: A total of 605 CEAs were analyzed (395 C and 210 NC). Demographics were similar except for coronary artery disease (C 54.3% vs. NC 41.6%, P = 0.003). There was no statistically significant difference in 30-day (C 99.7% vs. NC 99.5%, P > 0.99) or 5-year survival (C 80.0% vs. NC 83.7%, P = 0.26) or 30-day stroke rate (C 0.3% vs. NC 1.0%, P = 0.28). No late ipsilateral strokes occurred during 5-year follow-up. The 5-year freedom from restenosis >30% (C 85.3% vs. NC 86.4%, P = 0.33), restenosis >50% (C 94.5% vs. NC 95.5%, P = 0.44), and restenosis >70% (C 98.6% vs. NC 98.9%, P = 0.73) were similar. Two patients underwent carotid stenting for restenosis >70%. Two patients (both in the C group) developed occlusion of the carotid artery. CONCLUSIONS: The thrombosis and restenosis rates in the 2 groups were similar. This suggests that collagen-impregnated patches do not initiate thrombosis or increase restenosis rates after CEA.

Contemporary midterm echocardiographic outcomes of Bentall procedure and aortic valve sparing root replacement.

BACKGROUND: Valve sparing root replacement (VSRR) and aortic valve repair (AVr) is an attractive treatment option compared with composite valve and root replacement (Bentall procedure) for patients with aortic root dilatation with or without aortic valve disease. While aortic valve preservation reduces the risk of valve-related complications, little is known about echocardiographic differences at follow-up between these 2 strategies. METHODS: Consecutive nonemergent patients undergoing VSRR and AVr (n=68) were compared with contemporary historical controls undergoing the Bentall procedure for aortic root pathology with or without mixed aortic valve disease (insufficiency or stenosis) (n=96). The VSRR was performed preferentially using the reimplantation technique. Bentall procedure utilized a mechanical valve in 65% of patients, a biologic prosthesis in 22%, and a homograft in 13%. Clinical and echocardiographic data were obtained at baseline and at follow-up (median=30 months). RESULTS: The 2 cohorts were similar with respect to all preoperative characteristics with the exception of disease etiology. The Bentall group had a higher proportion of degenerative valve and root disease (47.8% vs 27.9%) and a lower proportion of bicuspid aortic valve disease (22.8% vs 51.5%) as compared with the VSRR group (p=0.007). Postoperative echocardiographic outcomes were comparable between groups with the exception of higher peak (23.37±11.80 vs 18.0±12.04; p=0.02) and mean (13.07±7.53 vs 9.56±6.49; p=0.01) transvalvular aortic gradients in the Bentall group. Persistence of left ventricular dysfunction (8.4% vs 6.1%; p=0.61), presence of greater than moderate aortic valve (AV) insufficiency (3% vs 4.6%; p=0.32), and left ventricular mass (213.24±72.36 vs 207.38±63.07, p=0.61) were comparable between the Bentall and VSRR group, respectively. Finally, survival (p=0.21) and freedom from valve-related events (p=0.74) were similar between groups. CONCLUSIONS: Valve sparing root replacement with AV repair provides similar mid-term echocardiographic and clinical outcomes compared with the Bentall.

An unusual case of cardiogenic shock: common cause from uncommon etiology.

Mechanical complications of an acute coronary syndrome can lead to hemodynamic instability out of proportion to the degree of left ventricular dysfunction. We present the case of a patient with cardiogenic shock secondary to severe mitral regurgitation in the setting of an acutely occluded obtuse marginal artery. Echocardiography and pathologic findings revealed an uncommon cause of anterolateral papillary muscle rupture. Using the unique features of this case, we present a clinical self-assessment exercise highlighting the challenges involved in the management of this type of patient.

Acute mitral regurgitation in suspected acute coronary syndrome: what is the cause?

Patients presenting with acute chest pain and suspected acute coronary syndrome (ACS) who have nonobstructive coronary disease on angiography, but new regional wall motion abnormalities are often diagnosed with takotsubo cardiomyopathy (TTC). The cause of TTC is often physical or emotional stress, and this clinical syndrome occurs more often in women than men. When hemodynamically significant mitral regurgitation (MR) accompanies TTC, the mechanism must be carefully elucidated, as systolic anterior motion (SAM) of the mitral valve can cause significant MR and left ventricular outflow tract (LVOT) obstruction. These patients can be conservatively managed, with SAM-associated MR and LVOT obstruction resolving with medical therapy as TTC-associated left ventricular (LV) dysfunction resolves, as opposed to true ACS where further intervention for MR is often necessary. This case report describes 2 cases of TTC presenting with severe MR, who were initially thought to have ACS-associated MR caused by ischemia, but on further echocardiographic interrogation were found to have SAM-associated MR which resolved along with resolution of LV wall motion abnormalities on medical therapy by follow-up echocardiography.

The challenge of timing surgery in a complex case of endocarditis.

While the results of clinical trials are useful in guiding management of the "average" patient, physicians are often left to their own devices when confronted with cases that neither fulfil the entrance criteria for clinical trials nor conveniently match evidence-based guidelines. We present a teaching exercise, built around a complex case of endocarditis, in a branched self-assessment format that challenges the reader's clinical judgement. The case involves a woman aged 45 years with decompensated liver cirrhosis who presents with endocarditis complicated by heart failure and multiple systemic emboli. The risk-to-benefit ratio for urgent surgical intervention tilts as the complications accumulate.

Unusual cause of an ejection murmur: myxoma in the left ventricular outflow tract.

We present the case of a healthy, asymptomatic 50-year-old woman with a systolic ejection murmur who was found to have an obstructive left ventricular outflow tract mass. Transthoracic echocardiography revealed a large mobile mass attached to the basal anterior septum of the left ventricle. Surgical resection was performed and a benign left ventricular outflow tract myxoma was diagnosed. The patient's postoperative course was unremarkable. We describe the clinical presentation and role of 2- and 3-dimensional transthoracic and transesophageal echocardiography in surgical management.

Clinical comparative study: efficacy and tolerability of tolperisone and thiocolchicoside in acute low back pain and spinal muscle spasticity.

STUDY DESIGN: We performed a multicentric, randomized, comparative clinical trial. Eligible patients were randomly assigned to receive 150 mg of Tolperisone thrice daily or 8 mg of Thiocolchicoside twice daily for 7 days. PURPOSE: To assess the efficacy and tolerability of Tolperisone in comparison with Thiocolchicoside in the treatment of acute low back pain with spasm of spinal muscles. OVERVIEW OF LITERATURE: No head on clinical trial of Tolperisone with Thiocolchicoside is available and so this study is done. METHODS: The assessment of muscle spasm was made by measuring the finger-to-floor distance (FFD), articular excursion in degrees on performing Lasegue's maneuver and modified Schober's test. Assessment of pain on movement and spontaneous pain (pain at rest) of the lumbar spine was made with the help of visual analogue scale score. RESULTS: The improvement in articular excursion on Lasegue's maneuver was significantly greater on day 3 (p = 0.017) and day 7 (p = 0.0001) with Tolperisone as compared to Thiocolchicoside. The reduction in FFD score was greater on day 7 (p = 0.0001) with Tolperisone. However there was no significant difference in improvement in Schober's test score on day 3 (p = 0.664) and day 7 (p = 0.192). The improvement in pain score at rest and on movement was significantly greater with Tolperisone ((p) = 0.0001). CONCLUSIONS: Tolperisone is an effective and well tolerated option for treatment of patients with skeletal muscle spasm associated with pain.

Temporal trends and patterns of early clopidogrel use across the spectrum of acute coronary syndromes.

BACKGROUND: Randomized trials have established efficacy of clopidogrel in various types of acute coronary syndromes (ACS). The objective of this study was to examine the temporal trends and patterns of early clopidogrel use (within the first 24 hours of hospitalization) across the spectrum of patients with ACS in Canada. METHODS: Using the multinational, prospective GRACE (Global Registry of Acute Coronary Events) and GRACE(2), we identified 11,177 patients who were admitted for ACS from January 2003 to December 2007 in Canada. Demographic information, clinical features, and treatment were recorded. We examined the early use of clopidogrel over time and in relation to the type of ACS, clinical features on presentation, and the mode of reperfusion therapy. RESULTS: Of the 11,177 patients with ACS, 3,091 (27.7%) had ST-elevation myocardial infarction (STEMI), 5,194 (46.5%) had non-STEMI, and 2,892 (25.9%) had unstable angina; the rates of early clopidogrel administration were 63.0%, 66.6%, and 57.2%, respectively (P < .001). Overall, there was a significant increase in clopidogrel use over the period studied (P for trend < .001). In patients with non-ST-elevation ACS (non-STEMI and unstable angina), clopidogrel use was higher among those with positive cardiac biomarkers compared to those without (67.1% vs 59.8%, P < .001) but similar in the groups with and without ST deviation. There was an inverse relationship between GRACE risk score and rates of early clopidogrel administration. In patients with STEMI receiving fibrinolytic therapy, only 55.7% of patients <65 years old received clopidogrel compared with 47.0% and 42.6% of patients 65 to 74 and >75 years old, respectively (P for trend < .001). CONCLUSIONS: Although early use of clopidogrel therapy has increased over time across the spectrum of ACS, a significant proportion of eligible patients still do not receive this evidence-based therapy. There is a need to optimize the use of proven antiplatelet therapies to improve clinical outcome.

Carotid reconstruction in nonagenarians: is surgery a viable option?

Because of limited longevity and perceived increased perioperative risk, the optimal treatment of significant carotid stenosis in nonagenarians is controversial. This study was conducted to evaluate our results in this demographic group. A retrospective review was performed of carotid endarterectomies (CEAs) done in nonagenarians at Cedars-Sinai Medical Center between 1996 and 2006. During this period, a total of 2,038 CEAs were performed on patients of all ages. Data abstracted included demographics, patient risk factors, indications for surgery, perioperative complications, and survival. Fifty-three (2.8%) CEAs were performed as the primary procedure on 49 patients aged 90 or greater during the study period. Of these patients, 11 (22.4%) had diabetes, 38 (77.5%) had hypertension, and 31 (63.3%) had coronary artery disease. Eleven patients (22.4%) had a history of smoking, and there were no current smokers. Renal disease was present in three (6.1%) patients, one of whom was dialysis-dependent. The median length of stay was 2 days with a range of 1 to 24 days. Five patients (10.2%) required the intensive care unit following surgery. There were no postoperative strokes, and none of the patients had suffered ipsilateral stroke during follow-up. One patient (1.8%) had a perioperative myocardial infarction. One patient died in the perioperative period (1.8%). The 1-month stroke and mortality results did not differ significantly from those in patients under the age of 90, 0.3% and 0.4%, respectively (p = nonsignificant by Fisher's exact test). Using Kaplan-Meier life-table analysis, the 1- and 5-year survival rates were 84 +/- 5% and 33 +/- 9%, respectively. Our study demonstrates that in a group of well-selected nonagenarians, CEA is a safe procedure with acceptable perioperative morbidity.

Access strategies for revision or explantation of the Charité lumbar artificial disc replacement.

BACKGROUND: Several lumbar disc prostheses are being developed with the goal of preserving mobility in patients with degenerative disc disease. The disadvantage of lumbar artificial disc replacement (ADR) compared with anterior interbody fusion (ALIF) is the increased potential for displacement or component failure. Revision or removal of the device is complicated by adherence of the aorta, iliac vessels, and the ureter to the operative site. Because of these risks of anterior lumbar procedures, vascular surgeons usually provide access to the spine. We report our experience with secondary exposure of the lumbar spine for revision or explantation of the Charité disc prosthesis. METHODS: Between January 2001 and May 2006, 19 patients with prior implantation of Charité Artificial Discs required 21 operations for repositioning or removal of the device. Two patients had staged removal of prostheses at two levels. One patient had simultaneous explantation at two levels. The mean age was 49 years (range, 31 to 69 years; 56% men, 42% women). The initial ADR was performed at our institution in 14 patients (74%). The mean time from implantation to reoperation was 7 months (range, 9 days to 4 years). The levels of failure were L3-4 in one, L4-5 in nine, and L5-S1 in 12. RESULTS: The ADR was successfully removed or revised in all patients that underwent reoperation. Three of the 12 procedures at L5-S1 were performed through the same retroperitoneal approach as the initial access. One of these three, performed after a 3-week interval, was converted to a transperitoneal approach because of adhesions. The rest of the L5-S1 prostheses were exposed from a contralateral retroperitoneal approach. Four of the L4-5 prostheses were accessed from the original approach and five from a lateral, transpsoas exposure (four left, one right). The only explantation at L3-4 was from a left lateral transpsoas approach. Nineteen of the 22 ADR were converted to ALIF. Two revisions at L5-S1 involved replacement of the entire prosthesis. One revision at L4-5 required only repositioning of an endplate. Access-related complications included, in one patient each, iliac vein injury, temporary retrograde ejaculation, small-bowel obstruction requiring lysis, and symptomatic, large retroperitoneal lymphocele. There were no permanent neurologic deficits, deep vein thromboses, or deaths. CONCLUSIONS: Owing to vascular and ureteral fixation, anterior exposure of the lumbar spine for revision or explantation of the Charité disc replacement should be performed through an alternative approach unless the procedure is performed < or = 2 weeks of the index procedure. The L5-S1 level can be accessed through the contralateral retroperitoneum. Reoperation at L3-4 and L4-5 usually requires explantation and fusion that is best accomplished by way of a lateral transpsoas exposure.

Treatment options for traumatic pseudoaneurysms of the paravisceral abdominal aorta.

Penetrating gunshot wounds (GSWs) to the abdominal aorta are frequently lethal. Alternative management options for treatment of traumatic pseudoaneurysms of the abdominal aorta are illustrated by three patient case histories. Patient A sustained two GSWs to the abdomen (midepigastrium, right subcostal region). He was hypotensive in the field. Emergent laparotomy was undertaken with suture ligature of a celiac injury and distal pancreatectomy/splenectomy for a pancreatic injury. Postoperative abdominal CT for an intraabdominal infection with leukocytosis revealed a 4 cm traumatic pseudoaneurysm of the abdominal aorta that extended from the suprarenal aorta to the level of the renal arteries. Six weeks later, he underwent an open repair. Patient B sustained multiple GSWs to his right arm and right upper quadrant. He was hemodynamically stable. He underwent abdominal exploration for a grade 3 liver laceration. Postoperative abdominal CT revealed a supraceliac abdominal aortic pseudoaneurysm. An aortogram demonstrated a 1.5 cm defect in the aortic wall above the celiac trunk communicating with the inferior vena cava (IVC). He underwent endovascular repair with covered aortic stent graft. Patient C sustained multiple thoracoabdominal GSWs. He was hemodynamically stable. Emergent laparotomy revealed multiple left colonic perforations, two duodenal lacerations, and an unsalvageable left kidney laceration. Postoperatively, he developed a duodenal-cutaneous fistula with multiple intraabdominal abscesses. Serial CT scans revealed an enlarging infrarenal aortic pseudoaneurysm. He underwent angiographic coil embolization and intraarterial injection of thrombin into the pseudoaneurysm sac. The average time from injury to surgical treatment was 46 days (range 29-67). Postoperatively, none of the patients developed paraplegia. Advances in endovascular techniques have provided options to deal with traumatic pseudoaneurysms of the abdominal aorta. In a hemodynamically stable patient with a traumatic pseudoaneurysm, careful selection of a specific intervention can be tailored to the clinical scenario electively.

Influence of crystallite size on acetone hydrogenation over copper catalysts.

Acetone hydrogenation was studied over a family of Cu/SiO2 catalysts as well as UHP Cu powder and a Cu chromite catalyst. Oxygen chemisorption via dissociative N2O adsorption was used to count surface Cu atoms and calculate crystallite sizes, and a microwave absorption technique was used to measure the electrical conductivity of these Cu particles. Under differential reaction conditions at 423 K and 1 atm, all catalysts exhibited deactivation on stream and activities were typically 10-20% of their initial values after 3-4 h on stream. However, initial turnover frequencies (TOFs) varied from 0.056 s(-1) on the most highly dispersed Cu catalyst to 0.50 s(-1) on Cu powder, with the highest TOF of 2.4 s(-1) occurring on 110 nm crystallites. A similar trend with a broader (80-fold) variation was observed in the "steady-state" TOF values. Apparent activation energies varied between 11 and 14 kcal/mol. These initial TOF values are in good agreement with previous results, and a correlation exists between TOF and Cu crystallite size in this reaction, which appears to be structure sensitive. In addition, the electrical conductivity of these dispersed Cu nanoparticles, which was always less than that of bulk Cu, also increased with increasing Cu crystallite size; consequently, the change in this parameter may offer a possible explanation for the increase in TOF.

Current endovascular management of atherosclerotic renal artery stenosis.

The recent advances in stent technology and renal endovascular management have provided a technically reproducible method of percutaneously treating atherosclerotic renal artery stenosis (RAS). In many centers, this has resulted in endovascular management being the primary therapy for atherosclerotic RAS. Although still controversial, it appears that endovascular management of RAS by primay stent deployment provides better blood pressure control than that afforded by best medical management. The impact on renal function is less than that found for hypertension, but there is evidence to suggest that the use of protection devices and primary stenting may enhance renal function outcomes. Whether the ultimate benefit of enhanced survival follows remains an important question and should be the subject of future prospective studies.