Marc S. Sussman

Neurologic injury in cardiac surgical patients with a history of stroke.

BACKGROUND Controversy still exists as to whether patients with previous stroke are at increased risk for neurologic complications after heart operations. METHODS We performed a prospective analysis of 1,000 consecutive patients undergoing cardiac operations requiring cardiopulmonary bypass, without hypothermic circulatory arrest. Of the 1,000 patients, 71 had previously documented stroke (study group); 2 control patients with no history of stroke were selected for each of these patients (control group, n = 142). There were no significant differences between the study and control patients with respect to established risk factors for neurologic complications. RESULTS Compared with controls, study patients took longer to awaken (12.6 +/- 10.9 versus 3.5 +/- 2.1 hours; p < 0.0001) and longer to extubate (29.5 +/- 29.3 versus 9.1 +/- 5.2 hours; p < 0.001), and had a greater incidence of reintubation (7 of 71, 9.9% versus 2 of 142, 1.4%; p < 0.01) and postoperative confusion (26 of 71, 36.6% versus 7 of 142, 4.9%; p < 0.001). There was a higher incidence of focal neurologic deficit among study patients (31 of 71, 43.7% versus 2 of 142, 1.4%; p < 0.001). These deficits included new stroke (6 of 71, 8.5%) as well as the reappearance of previous deficits (19 of 71, 26.8%) or worsening of previous deficits (6 of 71, 8.5%), without new abnormalities on head computed tomography or magnetic resonance imaging. Study patients with neurologic deficit had longer cardiopulmonary bypass times than did study patients without deficit (146 +/- 48.5 versus 110 +/- 43.3 minutes; p < 0.001). The 30-day mortality rate was greater in study patients than in controls (5 of 71, 7% versus 1 of 142, 0.7%; p < 0.02), with four deaths among the 6 study patients with a new stroke (66.7%). CONCLUSION This analysis identifies a group of patients at high risk for neurologic sequelae and confirms the vulnerability of the previously injured brain to cardiopulmonary bypass, as evidenced by reappearance or exacerbation of focal deficits in such patients.

Aortic valve replacement in the elderly. Risk factors and long-term results.

OBJECTIVE The current study was undertaken to determine long-term results of aortic valve replacement (AVR) in the elderly, to ascertain predictors of poor outcome, and to assess quality of life. SUMMARY BACKGROUND DATA Aortic valve replacement is the procedure of choice for elderly patients with aortic valve disease. The number of patients aged 70 and older requiring AVR continues to increase. However, controversy exists as to whether surgery devoted to this subset reflect a cost-effective approach to attaining a meaningful quality of life. METHODS This study reviews data on 247 patients aged 70 to 89 years who underwent isolated AVR between 1980 and 1995; there were 126 men (51%) and 121 women (49%). Follow-up was 97% complete (239/247 patients) for a total of 974.9 patient-years. Mean age was 76.2 +/- 4.8 years. Operative mortality and actuarial survival were determined. Patient age, gender, symptoms, associated diseases, prior conditions, New York Health Association class congestive heart failure, native valve disease, prosthetic valve type, preoperative catheterization data, and early postoperative conditions were analyzed as possible predictors of outcome. Functional recovery was evaluated using the SF-36 quality assessment tool. RESULTS Operative mortality was 6.1% (15/247). Multivariate logistic regression showed that poor left ventricular function and preoperative pacemaker insertion were independent predictors of early mortality. After surgery, infection was predictive of early mortality. Overall actuarial survival at 1, 5, and 10 years was 89.5 +/- 2% (198 patients at risk), 69.3 +/- 3.4% (89 patients at risk), and 41.2 +/- 6% (13 patients at risk), respectively. Cox proportional hazards model showed that chronic obstructive pulmonary disease and urgency of operation were independent predictors of poor long-term survival. Postoperative renal failure also was predictive of poor outcome. Using the SF-36 quality assessment tool, elderly patients who underwent AVR scored comparably to their age-matched population norms in seven of eight dimensions of overall health. The exception is mental health. CONCLUSIONS Aortic valve replacement in the elderly can be performed with acceptable mortality. Significant preoperative risk factors for early mortality include poor left ventricular function and preoperative pacemaker insertion. Predictors of late mortality include chronic obstructive pulmonary disease and urgency of operation. These results stress the importance of operating on the elderly with aortic valve disease; both long-term survival and functional recovery are excellent.

Recurrence after neoadjuvant chemoradiation and surgery for esophageal cancer: Does the pattern of recurrence differ for patients with complete response and those with partial or no response?

OBJECTIVE We hypothesized that most relapses in patients with esophageal cancer having neoadjuvant chemoradiation therapy would occur outside of the surgical and radiation fields. METHODS Recurrence patterns, time to recurrence, and median survival were examined in 267 patients who had esophagectomy after neoadjuvant chemoradiation therapy at Johns Hopkins over 19 years. RESULTS Of 267 patients, 82 (30.7%) showed complete response to neoadjuvant therapy, with 108 (40.4%) and 77 (28.8%) showing partial response or no response, respectively. Recurrence developed in 84 patients (patients with complete response 18/82, 21.4%; patients with partial response 39/108, 36.1%; patients with no response 27/77, 35.1%; P = .055, respectively). Most patients had recurrences at distant sites (65/84;77.4%) regardless of pathologic response, and subsequent survival was brief (median 8.37 months). Median disease-free survival was short (10 months) and did not differ based on recurrence site for patients with partial response or no response, but was longer for patients with complete response with distant recurrence, whose median disease-free survival was 27.3 months (P = .008). By multivariate analysis, no other factor except for pathologic response to neoadjuvant therapy was associated with disease recurrence or death. Patients with partial response or no response were 1.97 and 2.23 times more likely to have recurrence than patients with complete response (P = .024 and P = .012, respectively). CONCLUSIONS Most esophageal cancer recurrences after neoadjuvant therapy and surgery are distant, and survival time after recurrence is short regardless of pathologic response. Fewer patients achieving complete response had recurrences, and distant recurrences in these patients manifest later than in patients showing partial response and those showing no response. Only pathologic response is significantly associated with disease recurrence, suggesting that tumor biology and chemosensitivity are critical in long-term patient outcome.

Long-term Survival Outcomes by Smoking Status in Surgical and Nonsurgical Patients With Non-small Cell Lung Cancer: Comparing Never Smokers and Current Smokers

BACKGROUND Survival outcomes of never smokers with non-small cell lung cancer (NSCLC) who undergo surgery are poorly characterized. This investigation compared surgical outcomes of never and current smokers with NSCLC. METHODS This investigation was a single-institution retrospective study of never and current smokers with NSCLC from 1975 to 2004. From an analytic cohort of 4,546 patients with NSCLC, we identified 724 never smokers and 3,822 current smokers. Overall, 1,142 patients underwent surgery with curative intent. For survival analysis by smoking status, hazard ratios (HRs) were estimated using Cox proportional hazard modeling and then further adjusted by other covariates. RESULTS Never smokers were significantly more likely than current smokers to be women (P < .01), older (P < .01), and to have adenocarcinoma (P < .01) and bronchioloalveolar carcinoma (P < .01). No statistically significant differences existed in stage distribution at presentation for the analytic cohort (P = .35) or for the subgroup undergoing surgery (P = .24). The strongest risk factors of mortality among patients with NSCLC who underwent surgery were advanced stage (adjusted hazard ratio, 3.43; 95% CI, 2.32-5.07; P < .01) and elevated American Society of Anesthesiologists classification (adjusted hazard ratio, 2.18; 95% CI, 1.40-3.40; P < .01). The minor trend toward an elevated risk of death on univariate analysis for current vs never smokers in the surgically treated group (hazard ratio, 1.20; 95% CI, 0.98-1.46; P = .07) was completely eliminated when the model was adjusted for covariates (P = .97). CONCLUSIONS Our findings suggest that smoking status at time of lung cancer diagnosis has little impact on the long-term survival of patients with NSCLC, especially after curative surgery. Despite different etiologies between lung cancer in never and current smokers the prognosis is equally dismal.

Lateral MIDCAB grafting via limited posterior thoracotomy

OBJECTIVE Minimally invasive direct coronary artery bypass (MIDCAB) is a technique for coronary artery bypass grafting performed under direct vision without sternotomy or cardiopulmonary bypass. The approach has been used principally for primary single vessel grafting of the anterior or inferior coronary circulation. This initial experience presents a new lateral technique for patients with isolated circumflex coronary disease which can be used for both primary and reoperative revascularization with either saphenous vein or a free radial artery conduit. METHODS Lateral MIDCAB grafting of the circumflex coronary circulation was accomplished over a 33 month period at a single center using saphenous vein or free radial artery as the bypass conduit. Through a limited posterior thoracotomy, the lung is deflated and reflected superiorly. The pericardium is opened below the phrenic nerve to expose an obtuse marginal branch of the circumflex coronary artery. After heparinization, the coronary artery is temporarily occluded proximally and distally with local immobilization and an arteriotomy is performed. The distal anastomosis with running suture is followed by the proximal anastomosis on the descending aorta below the hilum of the lung using a side-biting clamp and radiopaque marker. Intraoperative transit time ultrasound flow measurements confirm adequate graft flow before wound closure. RESULTS To date, 19 patients have undergone this procedure with a mean follow-up of 12 months. A total of 12 patients received saphenous vein grafts and 7 patients received radial artery grafts. There was one death from arrhythmia on postoperative day 9. There was one elective conversion to conventional sternotomy due to inadequate exposure. Graft flows averaged 33.3 cc/min (range 5-87) and the mean postoperative length of stay was 4.5 days; 4 patients underwent recatheterization; 1 had graft occlusion and 2 received late postoperative catheter-based interventions. All patients are currently free of symptoms. CONCLUSIONS Lateral MIDCAB grafting provides focused revascularization to the circumflex distribution in both primary and reoperative settings. This approach avoids the hazards of resternotomy, eliminates cardiopulmonary bypass, and hastens postoperative recovery. These early results suggest the technique is effective at relieving symptoms and minimizing perioperative morbidity. Further experience at multiple centers will serve to define the ultimate capabilities of this new approach.

dPIRPLE: a joint estimation framework for deformable registration and penalized-likelihood CT image reconstruction using prior images

Sequential imaging studies are conducted in many clinical scenarios. Prior images from previous studies contain a great deal of patient-specific anatomical information and can be used in conjunction with subsequent imaging acquisitions to maintain image quality while enabling radiation dose reduction (e.g., through sparse angular sampling, reduction in fluence, etc). However, patient motion between images in such sequences results in misregistration between the prior image and current anatomy. Existing prior-image-based approaches often include only a simple rigid registration step that can be insufficient for capturing complex anatomical motion, introducing detrimental effects in subsequent image reconstruction. In this work, we propose a joint framework that estimates the 3D deformation between an unregistered prior image and the current anatomy (based on a subsequent data acquisition) and reconstructs the current anatomical image using a model-based reconstruction approach that includes regularization based on the deformed prior image. This framework is referred to as deformable prior image registration, penalized-likelihood estimation (dPIRPLE). Central to this framework is the inclusion of a 3D B-spline-based free-form-deformation model into the joint registration-reconstruction objective function. The proposed framework is solved using a maximization strategy whereby alternating updates to the registration parameters and image estimates are applied allowing for improvements in both the registration and reconstruction throughout the optimization process. Cadaver experiments were conducted on a cone-beam CT testbench emulating a lung nodule surveillance scenario. Superior reconstruction accuracy and image quality were demonstrated using the dPIRPLE algorithm as compared to more traditional reconstruction methods including filtered backprojection, penalized-likelihood estimation (PLE), prior image penalized-likelihood estimation (PIPLE) without registration, and prior image penalized-likelihood estimation with rigid registration of a prior image (PIRPLE) over a wide range of sampling sparsity and exposure levels.

Cardiac valve replacement in human immunodeficiency virus–infected patients

BACKGROUND Valve replacement in human immunodeficiency virus (HIV)-infected patients is being performed with increasing frequency, but the early and late results in these immunocompromised patients are not known. METHODS A 10-year retrospective clinical review was undertaken; patients and their physicians were contacted for follow-up clinical status. RESULTS Twenty-two HIV-infected patients underwent valve replacement between 1990 and 1999, with no operative or hospital deaths. Mean patient age was 37.6 years; 15 were men. Indications for operation were heart failure in 59% (13/22) and sepsis in 91% (20/22). There were 12 aortic valve replacements, seven mitral valve replacements, and three double valve replacements. Mechanical valves were used in 11, bioprostheses in seven, and homografts in four. Follow-up information was available in 20 of 22 patients (84%). At mean follow-up of 5 years, there were 10 late deaths, due to: intracerebral hemorrhage (2), heart failure (2), unknown cause (2), renal failure (1), AIDS (1), sepsis (1) and endocarditis (1). Of the 20 patients with active preoperative endocarditis, 4 (20%) developed recurrent endocarditis; freedom from recurrent endocarditis was 83% at 1 year. Intravenous drug abuse was reported in 16 patients; survival among these patients was 94% at 1 month and 50% at 5 years. Recurrent endocarditis was only seen in patients with continued intravenous drug abuse. CONCLUSIONS Valve replacement in HIV-infected patients has low operative risk, but late results are poor when HIV infection is associated with intravenous drug abuse, probably due to immunocompromise and continued high-risk behavior.

Successful Repair of an Atrioesophageal Fistula After Catheter Ablation for Atrial Fibrillation

Catheter ablation of arrhythmias can result in the rare but devastating complication of an atrioesophageal fistula. This complication can be associated with significant neurologic morbidity and high mortality and requires a high index of suspicion to facilitate life-saving surgical intervention. Herein, we report the successful repair of an atrioesophageal fistula after catheter ablation for atrial fibrillation.

Human immunodeficiency virus infection as a prognostic factor in surgical patients with non-small cell lung cancer

BACKGROUND The purpose of this study was to assess the effect of human immunodeficiency virus (HIV) infection on postoperative survival among non-small cell lung cancer (NSCLC) patients. METHODS A retrospective cohort study compared 22 HIV-infected lung cancer patients to 2,430 lung cancer patients with HIV-unspecified status who underwent resection at Johns Hopkins Hospital from 1985 to 2009. Subcohort comparative analyses were performed using individual matching methods. RESULTS Thirty-day mortality rates did not differ between HIV-infected and HIV-unspecified patients. Survival rates for HIV-infected lung cancer patients were significantly shorter than for HIV-unspecified patients (median, 26 versus 48 months; p=0.001). After adjustment, the relative hazard of mortality among HIV-infected NSCLC patients was more than threefold that of HIV-unspecified patients (adjusted hazard ratio, 3.08; 95% confidence interval: 1.85 to 5.13). When additional surgical characteristics were modeled in a matched subcohort, the association remained statistically significant (adjusted hazard ratio, 2.31; 95% confidence interval: 1.11 to 4.81). Moreover, HIV-infected lung cancer patients with CD4 counts less than 200 cells/mm3 had shortened median survival compared with patients whose CD4 counts were 200 cells/mm3 or greater (8 versus 40 months; p=0.031). Postoperative pulmonary and infectious complications were also elevated in the HIV-infected group (p=0.001 and p<0.001, respectively). After surgery, median time to cancer progression was shorter among HIV-infected patients (20.4 months) versus HIV-unspecified patients (p=0.061). CONCLUSIONS The HIV-infected NSCLC patients have more postoperative complications, rapid progression to disease recurrence, and poorer postoperative survival. Optimizing immune status before surgery and careful patient selection based on diffusion capacity of lung for carbon monoxide may improve patient outcomes.

Deformable registration of the inflated and deflated lung in cone-beam CT-guided thoracic surgery: initial investigation of a combined model- and image-driven approach.

PURPOSE Surgical resection is the preferred modality for curative treatment of early stage lung cancer, but localization of small tumors (<10 mm diameter) during surgery presents a major challenge that is likely to increase as more early-stage disease is detected incidentally and in low-dose CT screening. To overcome the difficulty of manual localization (fingers inserted through intercostal ports) and the cost, logistics, and morbidity of preoperative tagging (coil or dye placement under CT-fluoroscopy), the authors propose the use of intraoperative cone-beam CT (CBCT) and deformable image registration to guide targeting of small tumors in video-assisted thoracic surgery (VATS). A novel algorithm is reported for registration of the lung from its inflated state (prior to pleural breach) to the deflated state (during resection) to localize surgical targets and adjacent critical anatomy. METHODS The registration approach geometrically resolves images of the inflated and deflated lung using a coarse model-driven stage followed by a finer image-driven stage. The model-driven stage uses image features derived from the lung surfaces and airways: triangular surface meshes are morphed to capture bulk motion; concurrently, the airways generate graph structures from which corresponding nodes are identified. Interpolation of the sparse motion fields computed from the bounding surface and interior airways provides a 3D motion field that coarsely registers the lung and initializes the subsequent image-driven stage. The image-driven stage employs an intensity-corrected, symmetric form of the Demons method. The algorithm was validated over 12 datasets, obtained from porcine specimen experiments emulating CBCT-guided VATS. Geometric accuracy was quantified in terms of target registration error (TRE) in anatomical targets throughout the lung, and normalized cross-correlation. Variations of the algorithm were investigated to study the behavior of the model- and image-driven stages by modifying individual algorithmic steps and examining the effect in comparison to the nominal process. RESULTS The combined model- and image-driven registration process demonstrated accuracy consistent with the requirements of minimally invasive VATS in both target localization (∼3-5 mm within the target wedge) and critical structure avoidance (∼1-2 mm). The model-driven stage initialized the registration to within a median TRE of 1.9 mm (95% confidence interval (CI) maximum = 5.0 mm), while the subsequent image-driven stage yielded higher accuracy localization with 0.6 mm median TRE (95% CI maximum = 4.1 mm). The variations assessing the individual algorithmic steps elucidated the role of each step and in some cases identified opportunities for further simplification and improvement in computational speed. CONCLUSIONS The initial studies show the proposed registration method to successfully register CBCT images of the inflated and deflated lung. Accuracy appears sufficient to localize the target and adjacent critical anatomy within ∼1-2 mm and guide localization under conditions in which the target cannot be discerned directly in CBCT (e.g., subtle, nonsolid tumors). The ability to directly localize tumors in the operating room could provide a valuable addition to the VATS arsenal, obviate the cost, logistics, and morbidity of preoperative tagging, and improve patient safety. Future work includes in vivo testing, optimization of workflow, and integration with a CBCT image guidance system.