An alternative to left ventricular volume reduction.

BACKGROUND: Left ventricular (LV) remodeling leading to ventricular dilatation is ultimately a maladaptative process according to the law of Laplace. To counteract the wall stress increase, a new concept of reducing the LV cavity radius by changing the LV globular shape to a bilobular one through the insertion of transventricular splints has emerged. This procedure is tested in a model of congestive heart failure. METHODS: A bovine model was used (n = 9). Following splint insertion through a sternotomy, boluses of 2 liters of crystalloid were injected. After every bolus, hemodynamic measurements were performed without and with the splints tightened to a 10% and 20% stress level reduction, respectively. Comparisons between the 3 measurements were performed with analysis of variance test (p < 0.05). RESULTS: Splint tightening significantly reduced right and left heart pressures for central venous pressure (CVP) >10 mm Hg (CVP: 14.7 +/- 5.2, 12.1 +/- 5, 10.6 +/- 4.7 mm Hg, p < 0.001 for baseline, 10% and 20% stress level reduction, respectively; mean pulmonary artery pressure: 33.5 +/- 4.7, 31 +/- 4.4, 29.4 +/- 5.1 mm Hg, p < 0.001; pulmonary capillary wedge pressure: 20.5 +/- 2.8, 18.9 +/- 3.3, 17.5 +/- 3.1 mm Hg, p < 0.001). The same holds true for cardiac output (6.5 +/- 1.6, 6.7 +/- 1.4, 6.8 +/- 1.7 liter/minute, p < 0.001), whereas heart rate and mean arterial pressure were not affected. The systemic and pulmonary resistances did not vary significantly throughout the procedure. Importantly, none of the hemodynamic parameters worsened at any stage with the splints. CONCLUSIONS: In this model, hemodynamic parameters are improved with the splints for higher values of CVP, supporting the concept of reshaping the remodeled LV. This technique has the potential to improve patients with congestive heart failure.     

Videotape review leads to rapid and sustained learning

BACKGROUND: Performance review using videotapes is a strategy employed to improve future performance. We postulated that videotape review of trauma resuscitations would improve compliance with a treatment algorithm. METHODS: Trauma resuscitations were taped and reviewed during a 6-month period. For 3 months, team members were given verbal feedback regarding performance. During the next 3 months, new teams attended videotape reviews of their performance. Data on targeted behaviors were compared between the two groups. RESULTS: Behavior did not change after 3 months of verbal feedback; however, behavior improved after 1 month of videotape feedback (P <0.05) and total time to disposition was reduced by 50% (P <0.01). This response was sustained for the remainder of the study. CONCLUSIONS: Videotape review can be an important learning tool as it was more effective than verbal feedback in achieving behavioral changes and algorithm compliance. Videotape review can be an important quality assurance adjunct, as improved algorithm compliance should be associated with improved patient care.     

Left ventricular volume reduction and reconstruction in ischemic cardiomyopathy

Abstract Background: Ischemic cardiomyopathy can be the result of large or small my-ocardial infarctions or due to myocardial hibernation. Patients with an end-systolic volume index >100 mL/m² do not benefit from revascularization alone and require an operation that reduces ventricular volume. Various approaches to reduce ventricular volume have been described. We applied several of these techniques in patients with end-stage ischemic cardiomyopathy. Methods: Forty eight patients with end-stage ischemic cardiomyopathy (Class III-IV) underwent left ventricular volume reduction operations with coronary revascularization and mitral valve repair or Alfieri valvoplasty. Fourteen patients underwent interpapil-lary resections, 22 anterior resections, 4 posterior resections, 2 anterior and posterior resections, and 6 patients reduction of left ventricular volume with endocavitary patches. Results: All the techniques used improved left ventricular function. Analysis of mortality revealed that extensive resections (interpapillary, anterior, and posterior resection) had a 43% mortality. However, a limited resection or a ventricular reconstruction with an endocavitary patch had only a 12.5% mortality. When we changed our approach to a more conservative one, mortality was reduced from 26% the first 12 months to 13% in the last 15 months of the study. Conclusions: Ischemic cardiomyopathy has a poor prognosis if the end-systolic volume index exceeds 100 mL/m². Various procedures exist to reduce left ventricular volume. Extensive ventricular resections improve ventricular function, but have a high mortality. This led us to use other methods of ventricular volume reduction such as more conservative resections combined with left ventricular reconstructions or ventricular volume reduction with endocavitary patches. Mortality was reduced significantly by this approach. The patients that survived have remained Class I-II in a follow-up that extends up to 30 months. Surgical therapy of Class III-IV ischemic cardiomyopathy is feasible, but aggressive ventricular resections have a high mortality. We advocate a more reconstructive approach with limited or no ventricular resection.     

Temporal factors in the reduction of myocardial infarct volume by methylprednisolone.

With a canine model of myocardial infarction [ligation of the left anterior descending (LAD) coronary artery] and an intracellular stain for lactic dehydrogenase (LDH) to directly measure size of infarction, the influence of 30 mg. per kilogram of methylprednisolone sodium succinate was evaluted. The intravenous administration of a pharmacologic dose of methylprednisolone one, 2, or 3 hours after the onset of myocardial infarction significantly reduced the ultimate extent of myocardial necrosis, with the greatest reduction seen following the injection of the drug one hour after ligation. The left atrial pressure was significantly decreased by corticosteroid administration, whereas the cardiac index and peripheral vascular tone were improved insignificantly. Inconsistent and/or insignificant effects were observed in the systemic and coronary sinus blood gases and in those indices of myocardial metabolism which were determined. The potential impact of these findings on the clinical applicability of methylprednisolone sodium succinate in acute myocardial ischemia is discussed.     

Renal infarct volume and renal function decline in acute and chronic phases

Background

Acute renal infarction (ARI) is a rare disease. ARI causes decline in renal function in both the acute and chronic phases. However, the correlation between the volume of the infarction and degree of renal function decline has not been fully investigated. Therefore, we aimed to examine the relationship between the volume of the infarction and degree of renal function decline.

Methods

We performed a single-center, retrospective, observational study investigating clinical parameters and the volume of the infarction. The volume of the infarction was measured using reconstructed computed tomography data.

Results

A total of 39 patients (mean age, 72.6?±?13.2 years; men, 59%) were enrolled. The median infarction volume was 45 mL (interquartile range, 14–91 mL). The volume of the infarction was significantly associated with the peak lactate dehydrogenase (LDH) level (median, 728 IU/L; interquartile range, 491–1227 U/L) (r?=?0.58, p?<?0.01) and the degree of renal function decline in both acute and chronic phases (r?=??0.44, ?0.38, respectively, p?<?0.05). The peak LDH level was significantly correlated with the degree of renal function decline in the acute phase but not in the chronic phase (r?=??0.35, ?0.21; p?<?0.05, N.S., respectively).

Conclusions

The volume of the infarction may be a factor in the degree of renal function decline in ARI. Therefore, assessment of infarct volume in ARI is important.

     

Early and mid-term results of left ventricular volume reduction surgery for dilated cardiomyopathy

OBJECTIVE: To evaluate structure-oriented left ventricular volume reduction surgery (LVVRS). The purpose of this study was to report the early and mid-term results of left volume reduction surgery for dilated cardiomyopathy (DCM). METHODS: We performed LVVRS on 29 patients with DCM. The age of the patient ranged from 8 to 73 years (mean 58 +/- 18 years). There were 19 male patients (63%). Twenty-three patients were ischemic, 5 were non-ischemic, and 1 had salcoidosis. Twenty-three patients were in New York Heart Association class III or IV. Fourteen patients underwent the Dor operation, 11 underwent a septal anterior ventricular exclusion operation, and 6 underwent a modified Batista operation. Fifteen patients underwent mitral annuloplasty and 2 patients had mitral valve replacement. All patients were divided into two groups, a Dor group (n = 14) and non-Dor group (n = 15). Postoperative early results and mid-term survival rate were compared between the two groups. RESULTS: Hospital mortality was 13.8% (4/29). The causes of death were low-output syndrome (n = 3) and septic shock (n = 1). Survival rate was 80% at 1 year and 72% at 3 years. Two-year survival rate of Dor and non-Dor groups were 69.8% and 93.8%, respectively (p = 0.099). CONCLUSIONS: Early and mid-term results of LVVRS were satisfied, and the non-Dor operation tended to be superior in mid-term survival to the Dor operation. Long-term follow-up is warranted.     

超声监测肺减容术后早期右心功能

目的探讨肺减容术治疗慢性阻塞性肺气肿（COPD）对右心功能的影响。方法应用彩色多普勒超声技术，分别于术前、术后5～7d、术后12～14d、术后1个月、3个月测定26例接受肺减容术病人的右心收缩、舒张功能。结果右心收缩功能：术后5～7d心率（HR）、右心每搏输出量（RVSV）、右室射血分数（RVEF）、右室面积变化指数（FAC）降低（P〈0．01）；肺动脉平均压（PAP）、总肺血管阻力（TPR）增加（P〈0．05），术后12～14d上述指标除RVEF外与术前比较无统计学差异。术后3个月RVEF与术前比较无统计学差异。右室舒张功能：术后5～7d舒张早期快速充盈峰值流速（E），E峰流速积分（ETVI）、E／A下降，舒张晚期快速充盈流速（A），A峰流速积分（ATVI）增加（P〈0．01），术后3个月除E／A外与术前比较无差异。结论肺减容术后右心血流动力学指标可出现短暂变化，术后5～7d右心泵功能、舒张功能下降，肺动脉压及总肺血管阻力升高；收缩功能很快恢复，舒张功能恢复较慢。     

Salvage by volume reduction of chronic allograft rejection in emphysema.

BACKGROUND: We hypothesized that native lung volume reduction surgery (LVRS) would improve respiratory function in patients who had previously undergone single lung transplantation for emphysema and who were disabled by obliterative bronchiolitis. METHODS: Seven single lung transplant recipients who had advanced bronchiolitis obliterans syndrome (BOS grade 3b), absence of active infection, and suitable anatomy underwent native LVRS. Mean time from lung transplantation to LVRS was 39 +/- 17 months. RESULTS: Mean FEV1 rose from 684 +/- 164 ml before LVRS to 949 +/- 219 ml at 3 months after LVRS, an increment of 40% (p = .002). Mean 6-minute walk rose from 781 +/- 526 ft before LVRS to 887 +/- 539 ft at 3 months after LVRS (p = .031), and mean dyspnea index declined from 3.1 +/- 1.1 before LVRS to 1.6 +/- 0.5 at 3 months after LVRS (p = .010). Mean native lung volume declined from 2956 +/- 648 ml before LVRS to 2541 +/- 621 ml at 3 months after LVRS, but the change was not statistically significant (p = .12). Mean transplant lung volume was little changed before and after LVRS (2099 +/- 411 ml and 1931 +/- 607 ml, respectively, p = NS). There was also a trend toward increased ventilation and perfusion of the native lung and reduction in ventilation and perfusion of the transplant lung, but these changes did not achieve statistical significance. By six months after LVRS, three patients died (two as a consequence respiratory failure), and survivors began to show evidence of deteriorating spirometry. CONCLUSIONS: LVRS is capable of salvaging respiratory function in chronic allograft rejection in emphysema by reducing native lung hyperinflation. These benefits, however, appear to be limited in magnitude and duration by the severity of the underlying allograft dysfunction.     

A rat model of ischemic cardiomyopathy for investigating left ventricular volume reduction surgery

OBJECTIVE: The effects of volume reduction surgery (VRS) for ischemic cardiomyopathy are not fully understood. The development of a proper animal model will help to resolve this issue. METHODS: Study 1 (Noninvasive study): Twenty-six rats developed large akinetic left ventricular (LV) aneurysms or ischemic cardiomyopathy after anterior descending artery ligation (first surgery). Four weeks after the surgery, 13 rats underwent volume reduction surgery (second surgery) (VRS group), while 13 underwent rethoracotomy alone (sham group). Before the first surgery, and before and after the second surgery, the LV dimensions were measured by echocardiography, and the heart rate and systolic blood pressure were recorded by the tail cuff method. Study 2 (Invasive study): In 7 rats undergoing the VRS and 9 undergoing the sham operation, LV pressure was measured with a manometer-tipped catheter, immediately before and after the second surgery. RESULTS: Study 1: All rats survived the second surgery, after which LV end-diastolic diameter decreased and LV fractional shortening increased (both p < 0.001) in the VRS group. This group also increased heart rate after the second surgery (p < 0.05). Study 2: There were no differences in LV end-systolic or end-diastolic pressure between the two groups before and after the second surgery. CONCLUSIONS: This model enables reproducible physiological evaluation of the LV after VRS, and since the rats show postoperative survival, it provides a useful tool for various investigations.     

Importance of preserving the apex and plication of the base in left ventricular volume reduction surgery

OBJECTIVE: Volume reduction surgery for dilated cardiomyopathy has not yielded predictable outcomes. The purpose of this study was to clarify the efficacy of modified volume reduction surgery in preserving the left ventricular apex and reducing the left ventricular diameter at the base to maintain fiber continuity. METHODS: Heart failure was induced with propranolol in 12 dogs, and the animals were randomized into 2 groups. In one group the left ventricular wall was plicated between the 2 papillary muscles from the middle to the apex (apex-sacrificing volume reduction surgery, group A, n = 6), and in the other group plication was done from the base to the middle (apex-sparing volume reduction surgery, group B, n = 6). Left ventricular function was then compared between the groups by using echocardiography and sonomicrometry crystals. RESULTS: After volume reduction surgery, the fractional area change at the base in group B was greater than that in group A (40% +/- 3% vs 27% +/- 4%, P =.003). Cardiac output in group B was better than that in group A (2.5 +/- 0.2 vs 1.8 +/- 0.2 L/min, P =.023). Left ventricular end-diastolic pressure in group A was higher than that in group B (16 +/- 2 vs 8 +/- 1 mm Hg, P =.001). Fractional shortening in the long axis, as assessed by means of sonomicrometry, was better in group B than in group A. CONCLUSIONS: Apex-sparing volume reduction surgery capable of maintaining left ventricular fiber continuity provided better left ventricular function in both the systolic and diastolic phases than apex-sacrificing volume reduction surgery in the acute heart failure model. This modification might improve the results of left ventricular volume reduction surgery.     

Effect of variable annular reduction on functional tricuspid regurgitation and right ventricular dynamics in an ovine model of tachycardia-induced cardiomyopathy

ObjectiveTo investigate the effect of variable tricuspid annular reduction (TAR) on functional tricuspid regurgitation (FTR) and right ventricular (RV) dynamics in ovine tachycardia-induced cardiomyopathy.MethodsNine adult sheep underwent implantation of a pacemaker with an epicardial lead and were paced at 200 to 240 bpm until the development of biventricular dysfunction and functional TR was noted. During reoperation on cardiopulmonary bypass, 6 sonomicrometry crystals were placed around the tricuspid annulus (TA) and 14 were placed on the RV epicardium. Annuloplasty suture was placed around the TA and externalized to an epicardial tourniquet. After weaning from cardiopulmonary bypass, echocardiographic, hemodynamic, and sonomicrometry data were acquired at baseline and during 5 progressive TARs achieved with suture cinching. TA area and RV free wall strains and function were calculated from crystal coordinates.ResultsAfter pacing, changes in left ventricular (LV) ejection fraction and RV fractional area decreased significantly. Mean TA diameter increased from 25.1 ± 2.9 mm to 31.5 ± 3.3 mm (P = .005), and median TR (range, 0-3+) increased from 0 (0) to 3 (2) (P = .004). Progressive suture cinching reduced the TA area by 18 ± 6%, 38 ± 11%, 56 ± 10%, 67 ± 9%, and 76 ± 8%. Only aggressive annular reductions (67% and 76%) decreased TR significantly, but these were associated with deterioration of RV function and strain. A moderate annular reduction of 56% led to a substantial reduction of TR with little deleterious effect on regional RV function.ConclusionsA moderate TAR of approximately 50% may be most advantageous for correction of functional TR and simultaneous maintenance of regional RV performance. Additional subvalvular interventions may be needed to achieve complete valvular competence.     

Apical suction leads to severe ischemia of the ventricular apex.

OBJECTIVE: Apical suction devices allow displacement of the heart in off-pump coronary artery surgery. However, high vacuum pressure may injure the suctioned myocardium. It has been demonstrated that partial pressure of oxygen in the myocardium (ptiO(2)) is a sensitive and rapid indicator of myocardial ischemia. The purpose of this study is to evaluate the effect of apical suction on the ptiO(2) as an indirect measure of myocardial perfusion of the ventricular apex. METHODS: Twenty-six patients undergoing elective off-pump coronary surgery were studied. Intramyocardial ptiO(2) was continuously measured using a flexible catheter microprobe (Licox GMS mbH, Kiel, Germany). Patients were divided into two groups. In one group (Group A; n=14), the microprobe was intraoperatively inserted into the myocardium of the left ventricular apex. In the second group (Group B; n=12), the probe was inserted in the anterior wall of the left ventricle. Intramyocardial ptiO(2) monitoring was made with the heart in the resting position and after placing the apical suction device. RESULTS: In Group A, basal ptiO(2) was 15.3+/-7.4 mmHg. One minute after placing the apical suction device, the ptiO(2) significantly decreased to 2.3+/-1 mmHg (p<0.001). A progressive increase of ptiO(2) was observed immediately after the Xpose suction device was removed. ptiO(2) was 13.6+/-9.1 mmHg 5 min after releasing the suction cup and increased to 27.2+/-12.6 mmHg 20 min later. In Group B, basal ptiO(2) was 17+/-10.3 mmHg. No significant changes were observed in Group B after placing and removing the suction cup. CONCLUSIONS: Apical suction devices lead to severe ischemia of the suctioned myocardium. Collapse of coronary vessels due to vacuum pressure is a possible mechanism. Reperfusion occurs immediately after removing the suction cup and a significant reactive hyperemia is observed.     

Prolonged neoadjuvant combined androgen blockade leads to a further reduction of prostatic tumor volume: three versus six months of endocrine therapy

OBJECTIVES: In most clinical trials that have investigated the potential beneficial effects of neoadjuvant combined androgen blockade (CAB) in clinically localized prostate cancer, CAB has been given for 3 months, but no data are available on the influence of a longer duration of neoadjuvant CAB on the pathologic features of prostate cancer. METHODS: Prostatectomy specimens of 40 patients, randomized to 3 (n = 18) or 6 (n = 22) months of neoadjuvant CAB, were blindly evaluated with regard to tumor volume, pathologic stage, and surgical margins. The morphologically most vital tumor areas were investigated for nucleolar size and MIB-1 defined proliferative activity. RESULTS: The patients treated for 6 months had a median tumor volume 60% lower than the 3-month treatment group (P = 0.005). In the 6-month treatment group, no residual tumor could be found in 2 cases, but the proportion of prostatectomy specimens with seminal vesical invasion and positive surgical margins was not statistically different from that after 3 months. Compared with untreated controls, tumor proliferative activity assessed by MIB-1 immunoreactivity was significantly lower at 3 and 6 months of neoadjuvant CAB (P = 0.01). However, in 2 of 1 7 examined tumors that had been treated for 6 months, high MIB-1 scores suggested a development toward therapy-resistant cancer. CONCLUSIONS: Prolonged neoadjuvant CAB for 6 months leads to a further decrease in prostatic tumor volume compared with the findings after 3 months. In a few instances, residual tumor areas with substantial MIB-1 defined proliferative activity persist at 6 months, thus indicating that in at least some cases, despite the overall decrease in tumor size, cancer cells can continue the cell cycle under CAB.     

Safety and effectiveness of lung volume reduction surgery for treatment of chronic obstructive pulmonary disease

Lung volume reduction surgery (LVRS) has been proposed and performed in order to decrease dyspnea and improve wordly life without major impairments in oxygen-dependent patients affected by serious chronic obstructive pulmonary disease (COPD) and severe dyspnea that doesn't suffer drastic alterations notwithstanding rehabilitation procedures tailored for the specific case. The purpose of LVRS is to optmize thoraco-pulmonary dynamics, considerably compromised in these patients, relaxing the serious expiratory restraint to airflow and improving the muscular respiratory functionality. In this work the authors bring forth the physio-pathological foundations that justify the use of LVRS, also analyzing data brought by the international literature about surgery guidelines, short-term morbidity and mortality, clinical-functional effects and long-term survival. They also underline the need for careful evaluation research, aimed at getting a precise account of cardio-respiratory functional outcome, that will enable the positive accomplishement of the demanding and risky surgery, especially whenever the pathology has reached remarkable proportions or appears to be bilaterally localized. Only committing to painstaking analysis, setting and customization protocols, the latter especially addressing carefully chosen patients, can the surgeon rely on to achieve both short and long-term positive outcomes.     

Passive ventricular constraint to improve left ventricular function and mechanics in an ovine model of heart failure secondary to acute myocardial infarction

OBJECTIVE: This study investigated the effects on global cardiac function and myocardial energetics of limiting progressive dilatation after infarction by means of a woven polyester jacket cardiac support device. We hypothesized that placement of the cardiac support device results in a decrease in myocardial wall stress and improvement in cardiac function and myocardial energetics. METHODS: To investigate the effect of passive constraint on left ventricular function and mechanics, a total of 10 sheep were studied with pressure-volume analysis and magnetic resonance imaging. A baseline study was followed by the creation of an anterior infarct. After 1 week, the animals underwent a second study. The cardiac support device was then placed over the epicardium in 5 sheep; the remaining animals served as controls. A terminal study was performed at 2 months after the infarct. RESULTS: The cardiac support device group at the terminal study exhibited a decrease in end-diastolic volume (control 110.3 +/- 19.8 mL vs cardiac support device 67.6 +/- 4.7 mL, P =.006) and an improved ejection fraction (control 15.5% +/- 5.7% vs cardiac support device 29.46% +/- 4.42%, P =.008) relative to the control group. Myocardial energetics were also enhanced in the cardiac support device group, as evidenced by the significant improvements in potential energy (control 2015 +/- 503 mL. mm Hg/beat vs cardiac support device 885 +/- 220 mL. mm Hg/beat, P =.006), efficiency (control 39.4% +/- 13.6% vs cardiac support device 59.8% +/- 8.5%, P =.044), and oxygen consumption (control 0.072 +/- 0.013 mL O(2)/beat vs cardiac support device 0.052 +/- 0.007 mL O(2)/beat, P =.034). CONCLUSION: Passive constraint with the cardiac support device after infarct prevents further remodeling and may stimulate reverse remodeling in heart failure secondary to acute myocardial infarction. These results suggest that in human beings placement of the cardiac support device after a large anterior myocardial infarction may be effective in halting the remodeling process that often leads to end-stage heart failure. If proved effective, placement of a cardiac support device after large heart attacks has the potential to decrease the incidence of heart failure that results after large myocardial infarctions.