Ronald C. Elkins

Pulmonary autograft in children: Realized growth potential☆

Pulmonary autograft replacement of the aortic valve has the potential to remain viable and grow in proportion to the somatic growth of the child. Changes in aortic annulus and sinotubular dimensions were compared early and late postoperatively, and related to normal. Eighty-six children, 0.9 to 21 years, were operated on between 1986 and 1993: 42 had a root replacement, 24 an inclusion cylinder, and 20 a scalloped subcoronary implant. Actuarial survival at 7 years was 96.5% +/- 2.0%. Freedom from reoperation for the pulmonary autograft or the homograft reconstruction of the right ventricular outflow tract was 92% +/- 4%. Freedom from reoperation on the autograft in root replacements was 96% +/- 4%, in the inclusion cylinder was 100%, and in the scalloped subcoronary was 90% +/- 7% (not significant). Aortic annulus and sinotubular junction diameters were compared with normal values predicted by body surface area. In 22 intraaortic implants, early and late postoperative annulus diameter mean Z values are in the normal range. In the 23 root replacements, early annulus diameter was within the normal range, but late Z values were larger than normal (p < 0.02). Intraaortic implant annulus diameter increased proportionally to somatic growth, but the sinotubular junction, which was small, remained small but increased toward normal. In the root replacements, the annulus increased in diameter and became dilated. The sinotubular junction, which was small early, increased and was within the normal range late. Lower operative risk and valve durability without failure suggest improved results with inclusion cylinder technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Decellularized human valve allografts.

BACKGROUND Variable performance of allograft tissues in children and some adults may be linked to an immune response and could be mitigated by reducing implant antigenicity. METHODS As endothelial and fibroblast cells are the likely source of valve antigenicity, human (CryoValve SG) and sheep pulmonary valves were decellularized using the SynerGraft treatment process. Treated valves were evaluated in vitro using histochemical, biomechanical, and hydrodynamic methods, and compared with standard cryopreserved valves. Four SynerGraft-treated and two cryopreserved sheep pulmonary valves were implanted as root replacements in the right ventricular outflow tract of growing sheep and monitored echocardiographically and histologically at 3 and 6 months. CryoValve SG human pulmonary valves were implanted in 36 patients. RESULTS SynerGraft treatment reduced tissue antigen expression but did not alter human valve biomechanics or strength. Decellularized sheep allograft valves were functional during the implantation period, and, they became progressively recellularized with recipient cells. In humans, CryoValve SG pulmonary valves did not provoke a panel reactive antibody response. CONCLUSIONS SynerGraft decellularization leaves the physical properties of valves unaltered and substantially diminishes antigen content. Reduction in implant cellularity enables host recellularization of the matrix, which should favorably impact long-term graft durability.

Ross operation: 16-year experience

OBJECTIVE We performed a review of a consecutive series of 487 patients undergoing the Ross operation to identify surgical techniques and clinical parameters that affect outcome. METHODS We performed a prospective review of consecutive patients from August 1986 through June 2002 and follow-up through August 2004. Patient age was 2 days to 62 years (median, 24 years), and 197 patients were less than 18 years of age. The Ross operation was performed as a scalloped subcoronary implant in 26 patients, an inclusion cylinder in 54 patients, root replacement in 392 patients, and root-Konno procedure in 15 patients. Clinical follow-up in 96% and echocardiographic evaluation in 77% were performed within 2 years of closure. RESULTS Actuarial survival was 82% +/- 6% at 16 years, and hospital mortality was 3.9%. Freedom from autograft failure (autograft reoperation and valve-related death) was 74% +/- 5%. Male sex and primary diagnosis of aortic insufficiency (no prior aortic stenosis) were significantly associated with autograft failure by means of multivariate analysis. Freedom from autograft valve replacement was 80% +/- 5%. Freedom from endocarditis was 95% +/- 2%. One late thromboembolic episode occurred. Freedom from allograft reoperation or reintervention was 82% +/- 4%. Freedom from all valve-related events was 63% +/- 6%. In children survival was 84% +/- 8%, and freedom from autograft valve failure was 83% +/- 6%. CONCLUSIONS The Ross operation provides excellent survival in adults and children willing to accept a risk of reoperation. Male sex and a primary diagnosis of aortic insufficiency had a negative effect on late results.

Clinical experience with the Kim-Ray Greenfield vena caval filter.

Over a four year period in two institutions, 85 Kim-Ray Greenfield vena caval filters were inserted in 76 patients who have been followed for a minimum of 6 to 53 months. The most frequent indication for placement was pulmonary embolism during anticoagulant therapy. Both femoral and jugular routes were used for transvenous insertion, and fewer complications were associated with the jugular approach. Surgical mortality within two weeks of operation occurred in three patients (4%), none from recurrent embolism. Late complications included recurrent thrombophlebitis in 7% and persistent extremity edema in 12% of patients. Two patients developed recurrent embolism (2.6%) which also was seen in 2 patients after clips were placed on the vena cava above the filter after misplacement. Venacavagrams in 31 patients an average of 11 months postoperative showed patency in 30 (97%) and lysis of trapped thrombi in four patients. No episodes of migration have occurred and the filter offers the advantages of sustained patency and effective filtration without vena caval occlusion.

The Ross operation: a 12-year experience

BACKGROUND The Ross operation, originally introduced as a scalloped subcoronary implant with an 80% survival and 85% freedom from reoperation, has recently been modified to a root replacement which is now the most utilized implant technique. The mid and late results of this operative technique and comparison of intra-aortic implants and root replacement in a single institution are reported. METHODS The records of 328 patients who had a Ross operation at the University of Oklahoma (August 1986 to July 1998) were reviewed to assess operative technique and patient-related factors on survival, autograft valve function, homograft valve function, valve-related complications, and need for reoperation. RESULTS Operative survival was 95.4% with an actuarial survival of 89% +/- 5% at 8 years. Freedom from replacement of the pulmonary autograft was 94% +/- 3% at 8 years, freedom from reoperation on the pulmonary homograft was 90% +/- 4% at 8 years, and freedom from autograft valve reoperation or dysfunction (3+ autograft valve insufficiency) was 83% +/- 6% at 9 years. The incidence of autograft valve reoperation and late autograft valve dysfunction was decreased by root replacement. Annulus reduction and fixation improved early results in patients with aortic insufficiency and annulus dilatation. CONCLUSIONS Early results have been excellent, as the development of late autograft valve dysfunction or dilatation has been rare. The excellent hemodynamic results with a limited incidence of reoperation and replacement of the autograft valve justify its continued use.

The Ross Operation in Children: 10-Year Experience

BACKGROUND The Ross operation, first performed in children in 1968, may be the ideal aortic valve replacement. Technical demands of the operation and two valves at risk have delayed acceptance. A review of our experience to assess midterm and long-term results with the Ross operation is presented. METHODS The records of 150 consecutive patients, aged 7 days to 21 years (median age, 12 years, 75% less than 15 years) were reviewed. Follow-up was complete within the last 12 months (median, 2.8 years; range, 1 month to 10 years). Echocardiographic assessment was available on 116 (71%) within 1 year of closure and in 136 (91%) within 2 years. RESULTS Survival was 97.3% at 8 years. Late autograft valve dysfunction required replacement in 2 and reoperation with restitution of autograft function in 6. Freedom from reoperation for autograft dysfunction is 90% +/- 4% at 8 years. Freedom from reoperation for homograft obstruction is 94% +/- 3% at 8 years. Pulmonary homograft dysfunction (gradient > 40 mm Hg) was present in 4 additional patients. Freedom from reoperation on the homograft or a gradient of 40 mm Hg is 89% +/- 4% at 8 years. All patients have a normal, active lifestyle, without anticoagulants for their aortic valve replacement. CONCLUSIONS The Ross operation is the preferred operative replacement in children requiring aortic valve replacement.

Advantage of autograft and homograft valve replacement for complex aortic valve endocarditis

BACKGROUND There are advantages to using homografts and autografts as aortic valve replacements, particularly in patients with infective endocarditis. To better define these advantages, we reviewed our 13-year experience with the surgical management of infective endocarditis involving the aortic valve and root. METHODS From 1986 through 1998, 81 adults with aortic valve endocarditis underwent valve replacement (AVR). The mean age of the 65 men and 16 women was 44 +/- 14 years. Sixty-three (78%) patients had active endocarditis at the time of operation. Non-native valve endocarditis was present in 29 (36%) patients, in 9 of whom the infection was a recurrence. Aortic valve replacements were performed with 46 homografts (homo-AVR), 25 autografts (Ross-AVR), and 10 prosthetic valves (prosth-AVR). Among Ross-AVR and homo-AVR patients, 11 required mitral valve replacement or repair (homo-Ross DVR). Follow-up was 90% complete within 2 years of the end of the study with a mean of 3.7 +/- 3.4 years. RESULTS Early mortality was 16% (13 of 81 patients). This was 12% (3 of 25 patients) for Ross-AVR, 17% (8 of 46 patients) for homo-AVR, and 20% (2 of 10 patients) for prosth-AVR. Overall late mortality was 10% (7 of 68 patients) with a valve-related late mortality of 7% (5 of 68 patients). Actuarial survival at 5 years was 88% +/- 9% in Ross-AVR, 69% +/- 11% in homo-AVR, and 29% +/- 22% in prosth-AVR (p = 0.03). Endocarditis recurred in 12.5% (1 of 8 patients) with prosth-AVR and 3% (2 of 60 patients) in homo-Ross AVR. CONCLUSIONS Valve replacement in the presence of native and prosthetic endocarditis remains a formidable challenge. Autografts and homografts are the preferred replacement aortic valves for these patients even if concomitant mitral valve replacement is required, and risk of valve-related death or recurrent endocarditis is low at medium-term follow-up.

A 26-year experience with surgical management of tetralogy of fallot: risk analysis for mortality or late reintervention

BACKGROUND Over the past decade repair of tetralogy of Fallot (TOF) in infancy has gained favor. It is still uncertain what effect early complete repair will have on survival or late reoperation on the right ventricular outflow tract. METHODS To assess these outcomes, we reviewed our experience (1971-1997) with 294 patients undergoing operation at one institution. Median follow-up was 10.6 years (range, 0.1 to 26 years), and was complete for 90.2% patients. RESULTS Primary complete repair was done in 199 patients (68%), and a staged repair in 62 patients (21%). Thirty-three patients had only a palliative procedure. Sixty-eight patients (23.1%) had complex pathologic processes, including pulmonary atresia in 53. Hospital mortality for primary repair was 11.1% (22/199), for staged repair was 17.7% (11/62), and for palliative procedures was 15.5% (16/103 procedures). Since 1990 mortality has been 2.1%, 11.8%, and 0% respectively (p < 0.001), despite younger age at repair (0.6+/-0.1 versus 2.1+/-0.2 years; p < 0.001). Multivariate analysis identified longer period of hypothermic circulatory arrest, pulmonary artery patch angioplasty, earlier year of operation, and closure of the foramen ovale as risk factors for hospital death. For hospital survivors 20-year survival was 98%+/-3% for TOF with pulmonary stenosis and 88%+/-9% for TOF with pulmonary atresia (p=0.09). Reintervention on the right ventricular outflow tract was needed in 14.1% (37/261) patients. Freedom from reintervention on the right ventricular outflow tract at 20 years was 86%+/-4% for TOF with pulmonary stenosis and 43%+/-16% for TOF with pulmonary atresia (p=0.001). For the subgroup TOF with pulmonary stenosis, this was 85%+/-5% after primary repair and 91%+/-8% after staged repair (not significant). At 15-year follow-up, this was 78%+/-10% for patients not older than 1 year at operation compared with 88%+/-4% for older patients (not significant). CONCLUSIONS Early mortality after primary repair of TOF has significantly improved and late survival is excellent. Primary repair in infancy does not increase risk for reintervention on the right ventricular outflow tract.

Body surface area as a predictor of aortic and pulmonary valve diameter

BACKGROUND Predicting cardiac valve size from noncardiac anatomic measurements would benefit pediatric cardiologists, adult cardiologists, and cardiac surgeons in a number of decision-making situations. Previous studies correlating valve size with body size have been generated with the use of fixed autopsy specimens, angiography, and echocardiography, but primarily in the young. This study examines the relation of body surface area to measurements of the left ventricular-aortic junction (aortic valve anulus diameter) and the right ventricular-pulmonary trunk junction (pulmonary valve anulus diameter) in 6801 hearts across a wide spectrum of ages. METHODS From June 1985 to October 1998, cardiac valves from 6801 donated hearts were analyzed morphologically. Donor age was newborn to 59 years (mean 31 +/- 17 years; median 32 years). Calculated body surface areas ranged from 0.18 to 3.55 m(2). Aortic (n = 4636) and pulmonary valve diameters (n = 5480) were measured from enucleated valves suitable for allograft transplantation. Mean valve sizes were computed for ranges in body surface area in 0.1-m(2) increments. RESULTS For adult men (age >/= 17 years), the mean aortic valve diameter was 23.1 +/- 2.0 mm (n = 2214) and the mean pulmonary valve diameter was 26.2 +/- 2.3 mm (n = 2589). For adult women, the mean aortic valve diameter was 21.0 +/- 1.8 mm (n = 1156) and the mean pulmonary valve diameter was 23.9 +/- 2.2 mm (n = 1408). The mean indexed aortic valve area was 2.02 +/- 0.52 cm(2)/m(2) and the pulmonary valve area 2.65 +/- 0.52 cm(2)/m(2). Between 82% and 85% of the variability was explained by the size of the patient. Regression equations were developed both overall and separately for men and women, although the additional contribution of sex above that of body size was less than 1%. CONCLUSIONS Aortic and pulmonary valve diameters are closely related to body size. Thus, body surface area, when used in conjunction with other clinically accepted evaluations, is a useful tool for estimating normal aortic and pulmonary valve size.

Pulmonary autograft replacement in children. The ideal solution

Fifty-one children, aged 1.8 to 21 years (mean, 11.4) with aortic valve replacement using a pulmonary autograft are reviewed. Twenty-nine were intra-aortic implants and 22 were root replacements. There was one operative death, no late deaths, and two have required reoperation. Actuarial freedom from reoperation was 93% +/- 5.5 at 5.6 years. Freedom from progression of aortic insufficiency (AI) was 81% +/- 9 at 5.6 years in the intra-aortic implants and 86% +/- 10 in the root replacement. Enlargement of the pulmonary autograft was seen echocardiographically in both groups. This enlargement was consistent with somatic growth and not associated with progression of AI. Ten of 19 patients with aortic stenosis had an LV mass index suggestive of LV hypertrophy before operation. At 1 year, 18 of 25 had a normal LV mass index. Thirteen of 16 patients with AI had preoperative abnormal LV mass index. All but four returned to normal by 1 year. Low operative risk, excellent function, resolution of abnormal LV hemodynamics, and enlargement consistent with somatic growth suggest that the pulmonary autograft is the ideal replacement for the malfunctioning aortic valve.