Joseph N. Cunningham

Public reporting of surgical mortality: a survey of New York State cardiothoracic surgeons

BACKGROUNDnPublic disclosure of individual surgeons mortality following coronary artery bypass (CAB) is part of the New York State Department of Health Cardiac Surgery Reporting System (CSRS). The effects on the practice of cardiac surgery, as perceived by surgeons, remain unknown.nnnMETHODSnAll 150 New York State cardiac surgeons were sent an anonymous mail survey in 1997. Data was analyzed to determine the dominant opinion regarding the CSRS.nnnRESULTSnOne hundred and four surgeons (69.3%) responded. The majority (70%) did not experience a change in practice. Data reporting was performed by the surgeon or an employee (58%). Many picked the incorrect definition of chronic obstructive pulmonary disease (COPD) (45%) or statistical method (60%). The aspect of CSRS most in need of improvement was gaming with risk factors (40%). Most surgeons (62%) refused to operate on at least one high-risk CAB patient over the prior year, primarily because of public reporting. Refusal was more common in surgeons in practice less than 10 years, those with less than 100 cases per year, and those with a mixed cardiothoracic practice (p < 0.05, Pearsons chi2 test). A significantly higher percentage of high-risk CAB patients were treated non-operatively, when compared with ascending aortic dissection patients (not disclosed) (p < 0.001, Wilcoxon signed ranks test).nnnCONCLUSIONSnThe public disclosure of surgical results may be based on imperfect data and appears to have resulted in denial of surgical treatment to high-risk patients.

Cardiac Binding in Experimental Heart Failure

BACKGROUNDnCardiomyoplasty is a potential therapy for heart failure. Its benefits are attributed to systolic augmentation (dynamic cardiomyoplasty) and prevention of cardiac dilatation (static cardiomyoplasty). To evaluate the static component, we used an artificial membrane for cardiac binding in a canine model of heart failure.nnnMETHODSnIntracoronary doxorubicin was administered weekly for 4 weeks to induce heart failure in 10 dogs, each of which was assigned to one of two treatment groups: (1) no treatment, or (2) cardiac binding. Hemodynamic data were obtained at operation and at 7 weeks after operation. Echocardiography was performed weekly.nnnRESULTSnLeft ventricular end-diastolic pressure and diameter, and right ventricular end-diastolic diameter increased in group 1 (from 9.6 +/- 6.1 to 19.6 +/- 2.3 mm Hg, p = 0.009; from 3.9 +/- 0.4 to 5 +/- 0.3 cm, p = 0.0013; and from 1.6 +/- 0.2 to 1.9 +/- 0.3 cm, p = 0.0036, respectively). Ejection fraction fell in group 1 from 0.60 +/- 0.10 to 0.40 +/- 0.04 (p = 0.0009) and in group 2 from 0.56 +/- 0.02 to 0.40 +/- 0.04 (p = 0.0001), but the difference between groups was not significant.nnnCONCLUSIONnCardiac binding reduces the ventricular dilatation associated with heart failure without exacerbating left ventricular dysfunction.

Cerebrospinal Fluid Drainage and Steroids Provide Better Spinal Cord Protection During Aortic Cross- Clamping Than Does Either Treatment Alone

We investigated whether intravenous methylprednisolone (30 mg/kg) before 30 minutes of aortic cross-clamping and after 4 hours could enhance the effects of cerebrospinal fluid drainage on spinal cord perfusion pressure and postoperative paraplegia when proximal blood pressure was controlled with sodium nitroprusside and partial exsanguination. Dogs were randomized into three groups: group 1 (n = 6), control; group 2 (n = 7), steroids; and group 3 (n = 6), steroids with cerebrospinal fluid drainage. During aortic cross-clamping, blood pressure proximal to the clamp decreased significantly in each group compared with baseline (p less than 0.05), but did not differ among groups (group 1 = 82.2, group 2 = 82.1, group 3 = 86.6 mm Hg, p greater than 0.05). Mean distal pressure decreased from systemic values to 8.4, 8.5, and 3.7 mm Hg, respectively, after aortic cross-clamping (p less than 0.05); these values did not differ from one another (p greater than 0.05). During aortic cross-clamping, cerebrospinal fluid pressure in groups 1 and 2 did not differ significantly compared with baseline (12.2 versus 8.2, 14.2 versus 10.7 mm Hg, p greater than 0.05), whereas in group 3 the baseline cerebral spinal fluid pressure of 10.7 mm Hg decreased to 0.4 mm Hg (p less than 0.05). Spinal cord perfusion pressure in group 3 was significantly higher than in groups 1 and 2 (3.3 versus -3.9 and -5.7 mm Hg, p less than 0.05), but did not differ between groups 1 and 2 (p greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of sodium nitroprusside on spinal cord perfusion and paraplegia during aortic cross-clamping

To evaluate the effects of sodium nitroprusside (SNP) on hemodynamics, cerebrospinal fluid dynamics, and neurological outcome after 30 minutes of thoracic aortic occlusion, we monitored proximal and distal blood pressure, cerebrospinal fluid pressure, spinal cord blood flow, and somatosensory evoked potentials. In group 1 (n = 6), no attempts were made to control proximal hypertension, whereas in group 2 (n = 6), proximal blood pressure was controlled with intravenous infusion of SNP. There was no significant difference in proximal or distal blood pressure or cerebrospinal fluid pressure between the two groups at baseline. During the crossclamp interval, the mean proximal aortic pressure rose from 108 +/- 21 to 146 +/- 14 mm Hg (p less than 0.001) in the control group, whereas the mean blood pressure in the SNP group was maintained at 99.8 +/- 12 mm Hg (p = not significant compared with baseline blood pressure). Mean distal aortic pressure decreased from systemic values to 23 +/- 7 mm Hg in control animals and to 11 +/- 5 mm Hg in the SNP group (p less than 0.005). In the latter group, cerebrospinal fluid pressure increased significantly from 10.6 +/- 1.9 to 20.1 +/- 5.5 mm Hg (p less than 0.005). In animals receiving SNP, spinal cord blood flow was decreased in the lower spinal cord segments and increased in the upper cord segments. When compared with controls, this difference did not reach significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous angiotensin converting enzyme inhibition moderates ventricular dysfunction caused by doxorubicin

The purpose of this study was to determine that the administration of an angiotensin converting enzyme (ACE) inhibitor enalapril would confer protection against doxorubicin‐induced experimental heart failure, and attenuate the development of left ventricular dysfunction.

Transthoracic intraaortic balloon pump: A simplified technique

A technique of transthoracic intraaortic balloon pump insertion and a clinical experience with 14 patients is reported. The technique of transthoracic intraaortic balloon pump insertion can be done in a rapid and atraumatic fashion. A short prosthetic graft is used, and intraaortic balloon pump removal does not require resternotomy. The technique is a safe alternative in postcardiotomy failure patients with inadequate peripheral arterial access.

Composite cardiac binding in experimental heart failure

BACKGROUNDnComposite cardiac binding consists of wrapping the heart with a synthetic membrane and a pericardial interposition. The goal of the present study was to apply composite cardiac binding to a canine model of heart failure.nnnMETHODSnTwenty dogs were randomized to 2 groups: untreated heart failure (group 1, n = 13) and heart failure pretreated by composite cardiac binding (group 2, n = 7). They received a total dose of 1 mg x kg(-1) of intracoronary doxorubicin over 4 weeks. Hemodynamic data were obtained at weeks 0, 7, and 12. All animals were followed up with weekly echocardiography for 12 weeks.nnnRESULTSnSurvival in group 1 was 54% and in group 2 was 100% at week 12 (p = 0.0438). Left ventricular end-diastolic pressure increased by 153% in group 1 and by 59% in group 2 (p = 0.0395) at week 12. Ejection fraction decreased by 27% in group 1 and by 19% in group 2 (p = 0.4401) at week 12.nnnCONCLUSIONSnComposite cardiac binding significantly prolongs survival and attenuates left ventricular dilatation and the increase in left ventricular end-diastolic pressure associated to chronic heart failure. Further evaluation in established heart failure is needed. Composite cardiac binding may be used for the prevention of recurrent dilatation following reduction ventriculoplasty.

STUDIES IN THORACIC AORTIC GRAFT INFECTIONS: THE DEVELOPMENT OF A PORCINE MODEL AND A COMPARISON OF COLLAGEN-IMPREGNATED DACRON GRAFTS AND CRYOPRESERVED ALLOGRAFTS

OBJECTIVEnA porcine model of thoracic aortic graft infection was created, and various anatomic sites and the timing of inoculation of the graft to induce infection were investigated. Ultimately, the ability of cryopreserved allograft to resist infection was compared with that of collagen-impregnated Dacron graft.nnnMETHODSnYorkshire pigs (n = 16) underwent placement of an expanded polytetrafluoroethylene patch graft in the ascending aorta and the left atrial appendage (phase I). Eight animals were immediately given a 50-mL bolus (1 x 10(8) cfu/mL) of Staphylococcus aureus whereas the other 8 received the infusion 24 hours later. Animals were put to death 8 weeks later and the grafts were sterilely explanted and analyzed via microbiologic culture and standard histologic procedures for evidence of infection. The results displayed that the aortic graft and a delay of induced bacteremia of 24 hours were more reliable methods of producing infection. During phase II, 13 pigs were randomized to receive either a collagen-impregnated Dacron graft (n = 6) or a cryopreserved allograft (n = 7) in the ascending aortic position only and infusion of S aureus 24 hours after the operation. The experiment then proceeded to completion.nnnRESULTSnPhase I results displayed that use of an aortic graft and induced bacteremia 24 hours after the operation was a more reliable and reproducible method of producing infection. In phase II, graft infection was present in 38.5% (5/13) of animals, with only 16.7% (1/6) in the collagen-impregnated Dacron graft group and 57.2% (4/7) in the cryopreserved allograft group becoming infected. There was no significant difference between the collagen-impregnated Dacron graft and cryopreserved allograft groups in the incidences of thoracic aortic graft infections (P =.27, Fisher exact test).nnnCONCLUSIONSnThis novel porcine model of thoracic aortic graft infection is a reproducible method for the investigation of thoracic aortic graft infections. The phase I study investigated the timing of the induced bacteremia and the most susceptible position of a graft. Phase II demonstrated that collagen-impregnated Dacron grafts are equivalent, if not superior, to cryopreserved allografts in resisting central vascular graft infections in the ascending aorta.

A multimodality approach lengthens warm ischemic time during aortic cross-clamping☆

To evaluate the effects of exsanguination, cerebrospinal fluid drainage (CSFD), steroids alone and in conjunction with CSFD on spinal cord perfusion pressure (SCPP), and neurological outcome following 70 min of normothermic spinal cord ischemia, we monitored proximal (Px BP) and distal (Ds BP) aortic blood pressure, cerebrospinal fluid pressure, and somatosensory evoked potentials (SEP) in 29 mongrel dogs. In all animals Px BP during aortic cross-clamping was controlled with partial exsanguination (40-50% circulating blood volume). Dogs were randomized into four groups (gp): gp 1 (n = 6) control; gp 2 (n = 8) steroids only (methylprednisolone 30 mg/Kg 10 min before aortic occlusion and 4 hr later); gp 3 (n = 8) CSFD only; gp 4 (n = 7) steroids and CSFD. Partial exsanguination effectively controlled Px BP during aortic cross-clamping in all groups. After the statistically significant decrease from preclamp values, mean Px BP did not differ among groups (78.9, 81.2, 80.5, and 80.3 mm Hg, respectively, P greater than 0.05). Mean Ds BP decreased from systemic values to 12.6, 16.8, 16.7, and 17 mm Hg, respectively, after aortic occlusion (P less than 0.05); these values did not differ from one another. CSFP did not change significantly from its baseline value while the aorta was cross-clamped in gp 1; CSFP was significantly reduced to 6.2 mm Hg in gp 2, steroid-treated animals (P less than 0.05 vs gp 1); a further significant reduction in CSFP was noted in gp 3 and 4 undergoing CSFD (0.07 and 0.67 mm Hg, respectively, P less than 0.05 vs gp 1 and 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Pleural Drainage After Repair of Tetralogy of Fallot

Abstract Prolonged pleural effusion after congenital heart surgery results in extended hospitalization. Pleural drainage was evaluated in 39 consecutive patients undergoing repair of tetralogy of Fallot, to identify risk factors for persistent pleural effusion. Duration and amount of drainage was examined by the Kaplan‐Meier method and risk factors were evaluated by univariable and multivariable analyses. Median time of pleural drainage was 6.1 days, range 3 to 42 days. Duration of pleural drainage correlated with length of hospital stay (p < 0.0001). Postrepair right atrial pressure (p = 0.018) and preoperative hemoglobin (p = 0.035) were risk factors for persistent drainage. The presence of a previous right thoracotomy reduced drainage duration (p = 0.034). Prolonged mechanical ventilation increased the average daily volume of effusion (p < 0.0001). In conclusion, prolonged pleural effusion is an important morbidity factor after repair of tetralogy of Fallot. Bilateral chest tube insertion is indicated in patients with high preoperative hemoglobin and elevated postrepair right atrial pressure. Right thoracotomy is the preferred surgical approach when a preliminary palliative shunt is required.