Biomedical subjects

A Mazzucco

Publications and source records attributed to A Mazzucco.

At least 37 records · Page 2Linked to original sources

PubMed2000

Aortic valve replacement via minimal-access complete sternotomy.

Minimally invasive approaches to the chest for aortic valve replacement have been proposed recently in an attempt to reduce postoperative pain, length of hospital stay, and scarring. An alternative approach entailing a minimal skin incision and a complete median sternotomy is presented herein. This technique combines the advantage of limited cosmetic impact with the pattern of postoperative pain and the ventilatory mechanics typical of the sternotomy, which enables extubation upon skin closure and early discharge from the hospital.

Aortic Valve↗

PubMed2000

Experience with stentless aortic xenografts.

BACKGROUND AND AIM OF THE STUDY: The study aim was to define the long-term results after aortic valve replacement (AVR) with freehand stentless xenografts. METHODS: A retrospective analysis was performed of 376 consecutive patients (195 males, 181 females; mean age 70 +/- 7 years; range: 26-87 years) who underwent stentless AVR between October 1992 and April 2000. In total, 164 patients received Toronto SPV, 106 Biocor PSB, 101 Cryolife-O'Brien, and five other valves. Indication for surgery was valve stenosis (n = 246), regurgitation (n = 50), mixed lesion (n = 75) and prosthetic valve failure (n = 5). Mean preoperative NYHA functional class was 2.9 +/- 0.6 (range: 2-4). Associated procedures were required in 153 patients (41%), including coronary artery bypass grafting (n = 97), mitral operation (n = 26), ascending aortic replacement (n = 17) and 'other' (n = 13). Mean valve size was 25 +/- 3 mm (range: 21-29 mm), mean aortic cross-clamp time was 96 +/- 23 min (range: 42-186 min), and mean cardiopulmonary bypass time 128 +/- 34 min (range: 65-363 min). RESULTS: Ten patients (2.7%) died in hospital, due to cardiac causes (n = 6), cerebrovascular accident (n = 3) and multiorgan failure (n = 1). During a mean follow up of 40 +/- 20 months (range: 1-90 months) there were 33 late deaths. Survival was 96 +/- 1%, 83 +/- 3% and 80 +/- 4% and valve-related event-free survival 97 +/- 1%, 87 +/- 2% and 82 +/- 6% at one, five and seven years, respectively. Valve failure occurred in 21 (6%) patients (10 structural, nine non-structural, two endocarditis): freedom from structural valve deterioration was 99 +/- 1%, 95 +/- 2% and 92 +/- 4% at one, five and seven years. Reoperation on the xenograft was required in 17 (5%) patients, giving a freedom from reoperation of 99 +/- 1%, 94 +/- 2% and 90 +/- 4% at one, five and seven years. Freedom from valve failure and reoperation were significantly lower with Cryolife-O'Brien valves, but freedom from structural valve failure was similar. The average NYHA class was improved at follow up (1.4 +/- 0.7 versus 2.9 +/- 0.6 preoperatively, p = 0.01). CONCLUSION: Long-term survival and freedom from valve-related adverse events after stentless AVR in an elderly population were satisfactory. Freedom from structural deterioration was excellent and comparable for all xenograft models, while non-structural deterioration may have been more common with one valve model. Despite the advanced patient age, functional improvement late after operation may be expected.

Adult↗

PubMed1999

Pulmonary autograft replacement of the bicuspid aortic valve: a successful surgical option for young adults.

A severely dysfunctioning congenitally bicuspid aortic valve may require surgical treatment within the fourth decade of life. Among conventional options, the pulmonary autograft (PA) offers many theoretical advantages particularly for young patients, including potential for growth, hemodynamic performance, no need for anticoagulants and freedom from endocarditis. However the operation is more complex and longer, may interfere with coronary and right ventricular anatomy and function and may expose the patient to the downside of two valves at risk. Aim of this retrospective study was to evaluate the mid-term results achieved with the PA performed in adolescents and young adults with a bicuspid aortic valve. Between July 94 and June 98, 26 patients, 22 males and four females, with a mean age of 24+/-10 years (range, 11 to 38), underwent bicuspid aortic valve replacement with a pulmonary autograft (stenosis 2-8%; insufficiency 13-50%; combined 11-42%). Eight patients (31%) were in NYHA FC I, 17 (65%) in II, and 1 (4%) in III. Mean preoperative ejection fraction was 67+/-7%. Three patients (11.5%) had a past medical history of endocarditis (healed in all) and in two the PA was a re-do procedure. The PA was inserted as a subcoronary implant in one case (4%) and utilized as a root in the remaining 25 (96%). The right ventricular outflow tract was reconstructed with a cryopreserved pulmonary homograft conduit in all cases. Mean cardiopulmonary bypass and aortic crossclamp times were 204+/-50 min (range, 174 to 300) and 157+/-35 min (range, 133 to 193) respectively. No early or late deaths had occurred at a mean follow-up of 22.5 months (range, 5 to 47.5). The first patient in the series (4%) was reexplored for bleeding and needed transfusions. The subsequent routine use medical and surgical strategies resulted in no further need for postoperative reexploration, and successful containment of total postoperative blood loss (<350 ml/m2BSA). 2-D Echo evaluation of neo-aortic valve competence at 6 months, revealed no evidence of aortic valve regurgitation in 17 (65%), trivial regurgitation in seven (27%), mild in one (4%) and mild-to-moderate in one (4%). The latter patient (subcoronary implant PA) required reoperation. At six months, the mean degree of regression of left ventricular mass compared to pre-operative data, was 36% (333+/-94 to 212+/-60 gr, p<0.05). All patients are asymptomatic, in NYHA FC I, and enjoy normal social interaction. In conclusion, PA root implantation can be offered as a low-risk alternative to conventional prosthetic aortic valve replacement to adolescents and young adults with a bicuspid aortic valve. The routine achievement of blood loss containment has minimized the risk of transfusion thus contributing to expand the indication in young patients. Continued patients evaluation particularly with regard to evidence of neo-aortic valve degeneration, root dilatation and homograft dysfunction in the long term is warranted.

Adolescent↗

PubMed1999

Effects of open heart surgery on respiratory mechanics.

OBJECTIVE: To investigate the changes in respiratory mechanics in patients undergoing cardiac surgery before and after the operation. DESIGN: Prospective physiological study. SETTING: Operating theatre of the Institute of Cardiac Surgery, Verona, Italy. PATIENTS: 8 patients needing heart surgery because of a coronary bypass or mitral valve replacement. MEASUREMENTS AND RESULTS: We measured respiratory mechanics before and immediately after the surgical procedure with two techniques: (1) the rapid airway occlusion technique during constant flow inflation at different lung volumes, and (2) the negative expiratory pressure (NEP) technique. We found that static and dynamic elastance (15.3 +/- 3.3 and 19.0 +/- 5.5 cmH(2)O/l, respectively) and respiratory resistance, both airway and total flow resistance (5.8 +/- 2.5 and 10.3 +/- 4 cmH(2)O. l(-1). s, respectively) before surgery were slightly higher than in normal anaesthetised subjects. In all patients, the static inflation V-P curves fitted the power function and exhibited a slight upward concavity towards the volume axis (a = 16.9 +/- 3.5, b = 0.74 +/- 0. 07), indicating that elastance decreased with inflating volume. Whereas elastance increased by 30 %, neither intrinsic positive end-expiratory pressure, which was small, averaging 1.5 +/- 1.2 cmH(2)O, nor flow resistance changed after surgery. With the NEP technique, four patients exhibited expiratory flow limitation during the tidal expiration, for about 67 % of the exhaled volume, without changes after surgery. Arterial carbon dioxide tension (32 +/- 4 mm Hg) and pH (7.46 +/- 0.07) did not change, whereas arterial oxygen tension (PaO(2)) (242 +/- 34 mm Hg) decreased significantly by about 70 mm Hg, on average, with a constant fractional inspired oxygen (0. 50). CONCLUSIONS: This study shows that (1) respiratory mechanics can be abnormal in patients undergoing cardiac surgery, including expiratory flow limitation; (2) elastance increases and PaO(2) decreases after surgery; (3) simple, noninvasive techniques are available to measure respiratory mechanics in the operating theatre.

Aged↗

PubMed1999

Heparin-coated circuits for high-risk patients: a multicenter, prospective, randomized trial.

BACKGROUND: Heparin-coated circuits (HCCs) in low-risk cardiac patients who have coronary revascularization have a limited impact on postoperative outcome. In this prospective, randomized investigation, we studied high-risk patients who had cardiac operations with or without HCCs. METHODS: A total of 886 patients who had cardiac operations with cardiopulmonary bypass and at least one patient-related or procedure-related risk factor were enrolled in a multicenter study. They were randomly allocated to have cardiopulmonary bypass with Duraflo II HCCs (HCC group, n = 442) or conventional circuits (control group, n = 444). Postoperative outcome was investigated with respect to the occurrence of organ dysfunction. RESULTS: HCCs are associated with a shorter intensive care unit and postoperative hospital stay and with a lower rate of patients having a severely impaired clinical outcome (stay in intensive care unit for more than 5 days or death) (relative risk 0.66, p = 0.045). Lung dysfunction rate was significantly lower for the patients in HCC group affected by chronic obstructive pulmonary disease or who had mitral procedure (relative risk, respectively, 0.31, p = 0.018 and 0.05, p = 0.02). Renal dysfunction rate was significantly (p = 0.05) lower for diabetics in the HCC group (relative risk 0.28). CONCLUSIONS: When HCCs were used postoperative times decreased and they had a protective effect on lung and kidney function in high-risk patients.

Aged↗

PubMed1999

Preservation of the aortic valve in acute type A dissection complicated by aortic regurgitation.

BACKGROUND: The aim of the present study was to verify the efficacy of preserving the aortic valve in patients with acute type A aortic dissection complicated by significant aortic regurgitation. METHODS: From January 1979 to December 1996, 178 patients (125 males; mean age 57 +/- 9 years) underwent emergency surgery for acute type A aortic dissection, with an overall operative mortality rate of 21%. Based on a retrospective analysis of the preoperative angio- or echocardiographic findings, the 141 survivors were divided into 2 groups: Group 1 (G1) included 80 patients (57%) with no or mild aortic regurgitation, and Group 2 (G2) the remaining 61 patients with moderate-to-severe aortic regurgitation. The native aortic valve was preserved by means of a uniform technique consisting of reconstruction of the aortic root and sinotubular junction in 99 patients (70%) [68 in G1 (85%) and 31 in G2 (51%)]. Forty-two patients required aortic valve (8 patients; 6%) or total root replacement (34 patients; 24%). RESULTS: At a mean follow-up of 4 +/- 3.6 years (range, 6 months to 19 years), 19 of the 99 patients with a preserved aortic valve developed moderate-to-severe aortic insufficiency [19%; 7/68 in G1 (10%) and 12/31 in G2 (39%)]. Multivariate analysis revealed that moderate-to-severe preoperative aortic valve insufficiency was a significant risk factor for development of postoperative aortic valve regurgitation (p = 0.008). Reoperation was necessary in 7 G1 patients (10%) and in 8 G2 patients (26%), with an actuarial freedom from reoperation at 5 and 10 years of 93% +/- 7% and 80% +/- 9% in G1 patients, and 81% +/- 8% and 40% +/- 15% in G2 patients (p = 0.045). CONCLUSIONS: Preservation of the aortic valve and aortic root is recommended in patients with acute type A aortic dissection and absent or mild aortic insufficiency. Patients presenting with moderate-to-severe aortic regurgitation and treated conservatively present an increased risk of recurrent valvular insufficiency.

Adolescent↗

PubMed1999

Recurrence of aortic insufficiency after aortic root remodeling with valve preservation.

BACKGROUND: Aortic root remodeling (ARR) has recently been proposed for patients with aortic aneurysms and valve insufficiency (AI). To define factors associated with a favorable functional outcome, a review of the mid-term results with ARR was undertaken. METHODS: Between March 1994 and October 1997, 17 consecutive patients (11 men, 6 women), aged 57 +/- 11 years (range 35-71), had elective ARR for aortic aneurysm with or without annuloaortic ectasia (13), sinus of Valsalva aneurysm (3), or chronic aortic dissection (1). Moderate or severe AI was present in 11 patients (65%). Preoperative aortic root diameter was 58 +/- 5 mm (range 51-70). ARR involved replacement of all three aortic sinuses and coronary button reimplantation, using grafts with a mean diameter of 28 +/- 2 mm (range 24-30). RESULTS: There was one early death (6%) due to multiple organ failure. Survivors were followed for 16 +/- 12 months (range 1-44). Actuarial 3-year survival was 94% +/- 6%. Discharge echocardiogram showed a decrease in AI in all patients: AI was absent in 11 (69%) and mild in 5 (31%). Recurrence of moderate or severe AI after a mean of 16 +/- 9 months (range 9-28) was noted in 6 patients (37%), 3 of whom had no AI at discharge. Five of 6 patients required aortic valve replacement. Comparison of demographic and operative variables showed that severe preoperative AI (67% vs 20%, p = 0.06), annuloaortic ectasia (100% vs 20%, p = 0.002), and cystic medial necrosis (100% vs 20%, p = 0.002) were significantly more prevalent in patients developing severe AI at follow-up. The 10 patients (63%) with absent AI showed durable competence of the valve and relief from symptoms at follow-up. CONCLUSIONS: Despite early restoration of valve competence, AI may recur and progress after ARR at medium-term follow-up in a proportion of patients. The severity of preoperative AI and the nature of aortic root disease may negatively influence the durability of repair. Continued observation of results with ARR appears mandatory to identify the appropriate surgical candidates.

Adult↗

PubMed1999

Aortic root replacement with the Carboseal composite graft: 7-year experience with the first 100 implants.

BACKGROUND: Aortic root replacement remains a challenging surgical procedure. A variety of techniques and prosthetic devices have thus far been used. In order to assess the performance of the Carboseal (Sultzer Carbomedics, Inc, Austin TX) composite graft, review of the experience with composite root replacement was undertaken. METHODS: Between January 1979 and December 1998, 273 patients underwent composite aortic root replacement. One-hundred-six received the Carboseal composite prosthesis (group 1) and 84 other types of composite grafts (group 2). Demographic and operative variables were similar in the 2 patient groups, except for an older mean age in group 1 (58+/-12 versus 50+/-12 years, p = 0.001). RESULTS: Operative mortality was lower in group 1 patients (3 of 106, 3% versus 10 of 84, 12%, p = 0.04). Follow-up of survivors was longer in group 2 due to more recent adoption of the Carboseal grafts (93+/-57 versus 36+/-23 months, p = 0.01). Late mortality was higher in group 2 (3 of 103, 3% versus 13 of 74, 18%, p = 0.04), with higher prevalence of prosthetic-related complications (2 of 103, 2% versus 12 of 74, 15%, p = 0.002). Reoperation was more prevalent in group 2 (1 of 103, 1% versus 5 of 74, 8%, p = 0.04), and limited to patients having root replacement using the inclusion technique. Functional status of survivors was comparable in the 2 groups (83 of 103, 80% versus 45 of 74, 61% of patients in New York Heart Association class I, p = 0.1). CONCLUSIONS: Aortic root replacement using the Carboseal composite graft offers excellent long-term results, with negligible prevalence of prosthetic-related complications. Superior performance compared to other available composite grafts in the present series may be influenced by more recent adoption of the Carboseal conduit and concomitant uniform adoption of coronary button technique.

Aorta↗

PubMed1999

Blood versus crystalloid cardioplegia for myocardial protection of donor hearts during transplantation: A prospective, randomized clinical trial.

OBJECTIVE: To assess the safety and efficacy of myocardial protection of the donor heart during transplantation with the use of blood cardioplegia, a prospective randomized clinical trial was undertaken between January 1997 and March 1998. METHODS: Forty-seven consecutive patients were assigned either to crystalloid (27 patients; group 1) or blood cardioplegia (20 patients; group 2). Comparison of recipient age (54 +/- 11 years vs 55 +/- 7 years; P =. 9), sex (89% vs 90% male patients; P =.9), diagnosis (63% vs 65% dilated cardiomyopathy; P =.8), elevated pulmonary vascular resistance (30% vs 30%; P =.9), prior cardiac operations (22% vs 30%; P =.5), need for urgent heart transplantation (7% vs 20%; P =. 2), donor age (32 +/- 11 years vs 31 +/- 13 years; P =.7), cause of death (33% vs 40% vascular; P =.5), and global myocardial ischemia (176 +/- 51 minutes vs 180 +/- 58 minutes; P =.5) showed no difference. Hemodynamically unstable donors (15% vs 45%; P =.02) were more prevalent in group 2. RESULTS: Operative mortality rates (4% vs 5%; P =.8), high-dose inotropic support (41% vs 30%; P = 0.6), and postoperative mechanical assistance (11% vs 10%; P = 0.9) were comparable in the 2 groups. Prevalence of acute right heart failure (27% vs 0; P =.02) and of temporary complete atrioventricular block (52% vs 20%; P =.02) were greater in group 1. Spontaneous sinus rhythm recovery was more prevalent in group 2 (11% vs 40%; P =.02). Higher peak creatine kinase (1429 +/- 725 u/L vs 868 +/- 466 u/L; P =.01) and creatine kinase MB (144 +/- 90 u/L vs 102 +/- 59 u/L; P =. 06) levels suggested more severe ischemic injury in group I. CONCLUSION: Use of blood cardioplegia was associated with a lower prevalence of right heart failure, cardiac rhythm dysfunction, and laboratory evidence of ischemia.

Adult↗

PubMed1999

Routine left atrial catheterization for the post-operative management of cardiac surgical patients: is the risk justified?

OBJECTIVE: To assess the risk/benefit ratio, including cost, associated with routine left atrial catheterization for the post-operative management of patients after cardiac surgery. METHODS: From November 1991 to June 1998, out of 6187 open heart procedures performed at our institution, 5815 patients (94%) receive a left atrial monitoring line inserted invasively by a unique and reproducible technique. Catheters were removed on the first or second postoperative day before chest tube removal. A subgroup of 385 patients (7%) were switched to a Swan-Ganz catheter postoperatively. RESULTS: A total of 14 patients suffered a complication related to the left monitoring line (0.24%). Bleeding necessitating transfusion occurred in 10 patients (0.17%), seven of whom required surgical reexploration (0.12%). Catheter retention occurred in four cases (0.07%), requiring a mediastinal reexploration in one and a minimally invasive procedures in three, for removal. No other complications related to the presence of a left atrial line emerged in this series. Apart from providing crucial hemodynamic information on a routine basis, in nine selected patients (0.15%) in a low cardiac output state with increased pulmonary vascular resistance and right ventricular failure, the left atrial line was used as a preferential route for catecholamine infusion, with significant hemodynamic improvement. CONCLUSIONS: Complications of left atrial monitoring catheters in cardiac surgery do occur but at a very low and acceptable rate. No mortality was correlated to their use in our series. Complication rate can be further lowered by a meticulous management of the device. The wealth of information and therapeutic options offered by this line appears to outweigh the associated risk.

Cardiac Catheterization↗

PubMed1999

Mid-term results after heart valve replacement with the CarboMedics bileaflet prosthesis: experience with 785 implants.

BACKGROUND: The aim of the study was to evaluate our clinical experience with the CarboMedics Heart Valve Prosthesis. METHODS: Between October 1991 and December 1997, six hundred seventy-two consecutive patients (361 men, 54%; 311 women, 46%; mean age 57 +/- 12 year, range 6-73 years) underwent mechanical valve implantation at the Division of Cardiac Surgery of the University of Verona. Preoperatively, 69% of the patients were in NYHA FC III or IV. Eighty-one patients (12%) had undergone a previous cardiac operation and 14.5% had an ejection fraction less than 35%. We performed an aortic valve replacement in 309 patients (78 valved-conduits for replacement of the entire aortic root), a mitral valve replacement in 250, and a double valve in 113. 52 patients (8%) underwent associated myocardial revascularization. RESULTS: Early mortality was 2.8% (5/309 aortic, 1.6%; 11/250 mitral, 4.4%; 3/113 double, 2.6%). Late mortality was 4.4%. Actuarial survival at 5 years was 89.3% (aortic, 91.1%, mitral 86.4%, double 90.5%). Thromboembolism occurred in 26 patients (3.9%) and major hemorrhagic events in 20 (3%). Nine patients (1.3%) required a reoperation, in 3 cases (0.4%) after endocarditis (Staphylococcus epidermidis). No structural deterioration occurred in our series. CONCLUSION: Our study appears to confirm the safety and reliability of the CarboMedics mechanical valve prosthesis, even in old age groups. This bileaflet prosthesis demonstrates no structural deterioration, a low incidence of complications, and good hemodynamic performance.

Adolescent↗

PubMed1999

Factors influencing outcome after emergency surgical repair of acute type A aortic dissection.

OBJECTIVE: We retrospectively reviewed our more recent experience with acute type A aortic dissection in order to identify possible risk factors influencing current surgical results. METHODS: Between January 1990 and January 1998, 122 patients (86 males and 36 females; mean age 60 +/- 12 years) underwent emergency repair of acute type A aortic dissection using a standard surgical approach. Seventy-four (61%) patients required isolated replacement of the dissected ascending aorta, 27 (22%) required additional replacement of the aortic arch and 21 (17%) required total aortic root replacement. Surgical outcome was evaluated in terms of operative mortality and morbidity. Results of patients presenting with preoperative complications (Group C) (i.e. cardiac tamponade, cerebral stroke, cardiogenic shock, acute myocardial infarction, anuria or visceral ischemia) were compared with those of uncomplications cases (Group U) and with a calculated risk of expected operative mortality (EOM-rate) based on an analysis of each patient set of preoperative risk factors. Sixteen preoperative and 18 perioperative variables were also analyzed to identify conditions influencing morbidity and mortality. RESULTS: Fifty-seven patients (47%) presented with preoperative complications (Group C) and 65 (53%) did not (Group U). Overall operative mortality was 22% (27 patients). Mortality within subgroups was 40 and 6% for complicated and uncomplications cases, respectively (p < 0.001). The 85% of the overall mortality occurred in Group C patients. During the experience, the operative mortality rate actually observed ranged from 0 to 38% and was similar to the calculated expected risk, thus proving a direct relationship with the amount of complicated cases operated on each year. Multivariate analysis revealed that older age and hemopericardium significantly increased the risk of operative death, while male gender, preoperative complications, postoperative bleeding, duration of circulatory arrest and aortic cross-clamp time significantly predicted morbidity (p = 0.02). CONCLUSIONS: Current results of emergency repair of acute type A aortic dissection are strictly dependent on the number of complicated cases referred for operation. Earlier diagnosis and prompt referral before development of preoperative complications appear essential to improve surgical results.

Adult↗

PubMed1999

Risk factors for coronary complications after stentless aortic root replacement.

Coronary complications after aortic root replacement (ARR) with pulmonary autografts have been reported to be more common than with other stentless biological conduits (homografts, xenografts). To verify this hypothesis, results with 84 consecutive patients having stentless ARR between January 1992 and January 1999 were reviewed. Fifty patients had autograft (Group 1) and 34 either homograft or xenograft (Group 2) ARR. Comparison of age (27+/-9 vs. 38+/-22 years, P = ns), prevalence of male sex (86% vs. 79%, P = ns), aortic root disease (30% vs. 44%, P = ns), congenital coronary anomalies (10% vs. 3%, P = ns), prior aortic procedure (16% vs. 15%), and need for associated procedures (26% vs. 24%, P = ns), did not disclose significant differences. Bicuspid aortic valve was more prevalent in Group 1 (56% vs. 9%, P = .001). Mean aortic crossclamp (154+/-28 vs. 120+/-24 minutes, P = .05) and bypass (216+/-30 vs. 192+/-58 minutes, P = .05) times were longer in Group 1. Early mortality was comparable (2% vs. 3%, P = ns) and caused by right ventricular ischemia in both groups. Overall prevalence of coronary complications was higher in Group 1 (10% vs. 3%, P = .04), all resulting in right heart ischemia. Intraoperative partial takedown of repair in 5 Group 1 patients, associated with CABG in 1, resulted in prompt resolution of myocardial ischemia in 4 (80%) and prolonged in 1, which ultimately died as a result of sepsis. Recovery was prompt in all 4 patients (mean ICU stay 35+/-28 hours) with no metabolic or echocardiographic evidence of myocardial infarction. At discharge echocardiography, satisfactory biventricular kinetics was found in all patients. Analysis of preoperative variables showed bicuspid aortic valve (83% vs. 33%, P = .01) and coronary anomalies (67% vs. 3%, P = .001) to be more prevalent in patients suffering from coronary complications. Stentless ARR is a safe procedure with low operative mortality, regardless of the type of biological conduit. Autograft ARR may be at greater risk of right ventricular ischemia in patients with bicuspid aortic valve and coronary anomalies. An aggressive intraoperative approach including partial takedown of repair may limit the morbidity of coronary complications.

Adolescent↗

PubMed1999

Stentless aortic xenograft valve replacement: lessons learned after 300 implants.

Early results after aortic valve replacement (AVR) with three different types of stentless xenografts suggested less satisfactory outcome with a simplified implant model (Cryolife-O'Brien) compared with two standard implant models (Biocor PSB, Toronto SPV). To assess the impact of experience on mid-term outcome after stentless AVR, results with 322 implants were reviewed. Between July 1992 and February 1999, 106 patients underwent operations to implant the Biocor PSB (group 1), 139 patients the Toronto SPV (group 2), and 77 patients the Cryolife-O'Brien valve (group 3). Mean age (70+/-6 years; 70+/-7 years; 71+/-7 years; P = .7), prevalence of male gender (56 patients, 53%; 72 patients, 55%; 38 patients, 49%; P = .4), prevalence of aortic stenosis (72 patients, 68%; 77 patients, 55%; 38 patients, 49%; P = .7), and need for associated procedures (51 patients, 48%; 54 patients, 39%; 33 patients, 43%; P = .7) were similar among all three groups, respectively. Mean aortic cross-clamp time was shorter in group 3 (96+/-24 min; 98+/-24 min; 78+/-22 min; P = .02). Early deaths (3/106, 3%; 4/139, 3%; 2/77; 3%, P = .8) and late survival were comparable (89%+/-5%, 93%+/-4%, and 85%+/-7% at 5 years, P = .1) among groups. Follow-up ranged from 1 to 84 months (mean 52+/-20 months). Five-year freedom from valve deterioration (95%+/-5%, 96%+/-3%, and 85%+/-7%, P = .008) and from reoperation (98%+/-2%, 98%+/-2%, 92%+/-4%, P = .01) was significantly poorer in group 3 patients. When valve failure resulting from technical mishaps (none in the last 60 implants) with the Cryolife-O'Brien valve was excluded, no significant difference in freedom from valve deterioration was noted (98%+/-2%, 96%+/-3%, and 95%+/-4%, P = .1). Late functional status of 290 survivors was satisfactory and comparable among groups (1.3+/-0.8, 1.1+/-0.4, and 1.4+/-0.7 New York Heart Association class, P = .5). After an initial learning curve, simplified implant stentless xenografts offer satisfactory mid-term results, which are comparable to two-suture-line implant valves. Owing to the shorter grafting time, simplified implant xenografts such as the Cryolife-O'Brien may be particularly suited for complex operations where associated procedures are required.

Aged↗

PubMed1999

Diagnosis and early surgical management of traumatic thoracic aortic disruption.

OBJECTIVE: Traumatic rupture of the thoracic aorta is a major cause of death. Survival greatly depends on early diagnosis, degree of injuries to other districts and timing of repair. To address the controversial aspects of this condition, we retrospectively reviewed our experience. METHODS: Between April 1984 and December 1998, 39 patients (31 males, 79%), with a mean age of 33 +/- 7 (range, 17 to 59 years), underwent surgical repair at our institution. Final diagnosis of aortic disruption was achieved in 33 patients (85%) by aortogram, and in 6 (15%) by transesophageal echocardiography (TEE) alone. Four patients (8%) had a false negative chest X-ray on admission. Twenty-four patients (61.5%) had additional major injuries to other districts (n = 4, cranial trauma; n = 13, cranial trauma + pelvic fracture; n = 5, lesions to abdominal viscera; n = 2, lesions to abdominal viscera + pelvic fracture). Surgical techniques included simple aortic cross-clamping in 7 patients (18%), partial femoral-femoral bypass in 17 (44%), and partial left heart bypass in 15 (38%). Two patients underwent direct aortic suture (5%), whereas 37 (95%) had interposition of a vascular graft. RESULTS: Three patients (8%) died after major hemorrhaging during the early phases of our experience. Paraplegia occurred in 1 patient (2.5%) in the single aortic cross-clamping group. There was no morbidity directly attributable to the administration of heparin for cardiopulmonary bypass. CONCLUSION: Although aortography is still the gold standard to achieve diagnosis, the use of TEE as a method of detecting traumatic injury to the thoracic aorta appears feasible in critical patients, advantageously saving time. With a meticulous surgical approach and the use of an effective method for distal aortic perfusion during repair, it is possible to achieve good outcomes.

Adolescent↗

PubMed1998

Results of Biocor stentless valve replacement for infective endocarditis of the native aortic valve.

The mid-term results in a selected group of 9 patients with native aortic valve endocarditis managed by aortic valve replacement (with or without complex annular reconstruction) using a totally biological stentless valve are outlined. At a mean follow-up of 48 months, there are currently 7 survivors (2 late noncardiac deaths) with 100% freedom from reoperation, valve-related complication, and endocarditis.

Adult↗

PubMed1998

Methylenetetrahydrofolate reductase C677T mutation, plasma homocysteine, and folate in subjects from northern Italy with or without angiographically documented severe coronary atherosclerotic disease: evidence for an important genetic-environmental interaction.

Moderate elevation of plasma total homocysteine (tHcy) is a strong and independent risk factor for coronary artery disease (CAD). It can result from genetic or nutrient-related disturbances in the transsulfuration or remethylation pathways for Hcy metabolism. A point mutation (C677T; Ala-to-Val) in the gene encoding the 5, 10-methylenetetrahydrofolate reductase (MTHFR) has been recently reported to render the enzyme thermolabile and less active. Studies on the role of this mutation as a risk factor for CAD have given conflicting results. We studied a total of 415 subjects, 278 with angiographically documented multivessel CAD and 137 with angiographically documented normal coronary arteries. The overall frequency of the MTHFR V/V homozygous genotype was 15.7% (with 52.5% heterozygous and 31.8% normal). Subgroup analysis showed no significant differences between CAD and CAD-free subjects. A genotype/phenotype correlation study showed a marked effect of folate on the association between MTHFR genotypes and tHcy. Among individuals with folate levels below the median (11.5 nmol/L), fasting tHcy was significantly increased not only in V/V homozygotes (by 59%) but also, at intermediate values, in A/V heterozygotes (by 21% on average). Conversely, the mutation resulted neutral with respect to tHcy levels in subjects with adequate folate levels. We conclude that, in our population, the MTHFR C677T mutation is rather common, but it does not appear to be associated per se to CAD. A genetic-environmental interaction may contribute to the vascular risk by elevating tHcy when folate status is low.

Adult↗

PubMed1998

Recurrence of pulmonary hypertension after ventricular septal defect closure and perioperative response to nitric oxide.

The ability of inhaled nitric oxide to reduce pulmonary vascular resistance is currently used to select borderline patients for reparative surgery and to treat postoperative crises of pulmonary hypertension. A case of an infant with non-restrictive VSD who classified as a nitric oxide responder both in the catheterization laboratory and after surgery, but developed recurrent pulmonary hypertension is described. The limitations of inhaled nitric oxide in predicting the natural history of successfully operated patients are discussed.

Administration, Inhalation↗