We report the case of a 22-year-old woman in whom a focal aplasia of the pulmonary valve annulus associated with a multiple aneurysmal compensatory dysplasia was found. This patient had been followed since the age of seven years for a congenital asymmetric hypertrophic cardiomyopathy. Cardiac Doppler analysis showed significant pulmonary valvular insufficiency. The patient underwent heart transplant surgery because of total and refractory cardiac insufficiency. Pathological examination of the explanted heart (at the European Homograft Bank) enabled us to describe this valvular malformation. To date, this anomaly has not been described in the literature. Whether it is a malformation discovered fortuitously, or whether it is responsible in part for some of the signs associated with congenital hypertrophic cardiomyopathy is unclear. However, its role might be disclosed by a rigorous investigation of the patient's family.

How to cite: Fayad, G., Grandmougin, D., Abolmaali, K., Goffin, Y., Prat, A., Rey, C., & Warembourg, H. (1999). Multiple aneurysmal dysplasia of pulmonary valvular sinuses with congenital focal aplasia of the annulus. The Journal of heart valve disease, 8(6), 708–710.

Background and aim of the study: An increasing number of elderly patients are now requiring mitral valve surgery (MVS). However, due to a perceived increase in risk of morbidity and mortality following cardiac surgery, many elderly patients tend to be neglected or not referred for surgery.

Methods: The outcome of MVS in terms of hospital morbidity and mortality, length of intensive care unit (ICU) and hospital stays, and change in NYHA functional class and quality of life following surgery was assessed in 43 elderly patients (18 males, 25 females; median age 77 years (IQR 75-82 years)) who underwent primary open mitral valve repair (MVRr) or replacement (MVR) between November 1994 and September 1997. Their preoperative clinical characteristics, incidence of hospital morbidity, hospital mortality and length of ICU and hospital stays following MVS were recorded. At follow up, NYHA class was assessed and quality of life parameters monitored using the SF-36 questionnaire.

Results: At surgery, 69% of patients were in NYHA class III/IV, 36% underwent non-elective surgery and 44% had symptoms of more than three years' duration. Among patients, 80% presented with mitral incompetence and MVRr was undertaken in 51%. The median bypass and cross-clamp times for MVRr were significantly longer than for MVR. After surgery, 98% of patients required inotropic support, 9% renal dialysis, and 42% ventilatory support for >24 h. In addition, 37% developed respiratory complications, 12% renal failure, 19% needed re-exploration for bleeding, and 5% suffered a stroke. The mean ICU stay after surgery was three days; average in-hospital stay was 10 days. The 30-day mortality rate was 22.7% after MVRr and 38% after MVR. There was a significant improvement in energy, and role limitation due to physical and mental health after MVS.

Conclusions: Elderly patients underwent MVS, usually after a degree of clinical deterioration. Although morbidity and mortality following mitral valve surgery were high, at follow up there was a significant improvement in both symptoms and quality of life of survivors.

How to cite: Goldsmith, I., Lip, G. Y., Kaukuntla, H., & Patel, R. L. (1999). Hospital morbidity and mortality and changes in quality of life following mitral valve surgery in the elderly. The Journal of heart valve disease, 8(6), 702–707.

Background and aim of the study: Approximately 150,000 heart valves are implanted annually world-wide, of which 4% are implanted in the UK. We present a comprehensive profile of the trends in valve replacement (VR) surgery in the UK since 1986 based on data from the UK Heart Valve Registry (UKHVR).

Methodology: The UKHVR is a computerized database collecting prospective data on VR surgery in all UK cardiac units. All patients are tracked by national agencies who register all deaths of UK residents. Thus, the Registry receives a copy of each patient's death certificate and enters the date, place and certified cause(s) of death on the database.

Results: Between January 1st 1986 and December 31st 1997, a total of 58,195 patients underwent first-time VR surgery and received 63,649 valves. Mean age at operation in 1986 was 58.7 years (range: 18-87 years) and this rose to 64.7 years (range: 18-94 years) in 1997. In 1986, 12% (n = 578) of patients who underwent VR surgery were aged >70 years compared with 36% (n = 5125) in 1997. There was a 4% decrease in double VR surgery and a 15% reduction in mitral VR between 1986 and 1997. The majority of patients received a mechanical valve; within this group the number of bileaflet valve implants increased significantly since 1986. There has been a reversal in the downward trend in pericardial valves implanted since 1993. Follow up was 96.1% complete, with a total of 342,993 patient-years. Mortality (30-day) fell from 6.9% in 1986 to 3.8% in 1995, but increased to 6.7% in the two years to 1997. Actuarial survival at 1, 5 and 10 years was 89.5%, 78.5% and 61.8%, respectively; confidence intervals of 0.5% reflect the enormity of the database and quality of the data.

Conclusions: UKHVR data can provide comprehensive year-by-year and trend analyses in a database in excess of 63,000 valves. Changes in patient demographics, choice of implanted valve and the pattern of heart valve disease are evident within the UK over the past 11 years.

How to cite: Edwards, M. B., & Taylor, K. M. (1999). A profile of valve replacement surgery in the UK (1986-1997): a study from the UK Heart Valve Registry. The Journal of heart valve disease, 8(6), 697–701.

Background and aim of the study: The St. Jude Medical (SJM) mechanical heart valve was the first bileaflet valve with leaflets and orifice all fabricated from pyrolytic carbon. In 1992, a supra-annular cuff configuration, the SJM mechanical heart valve Hemodynamic Plus Series (HP), was introduced, which gave a one-size gain in orifice area over the standard valve. In a continuing effort to improve hydrodynamic performance, a new enhanced configuration of the mechanical valve - the SJM Regent valve - has been developed. The blood-contacting components of the SJM Regent valve have the same design features as those of the standard or HP valve, but the orifice lumen area has been increased, without compromising structural integrity, by a shift in the cuff-retaining orifice rims.

Methods: Valve performance has been measured using a laboratory simulation of the left heart system. Three samples of both valve types (SJM Regent, HP) for sizes 17 mm to 27 mm, were tested at a cardiac output of 5 l/min. Supplementary steady-flow measurements were made at flow rates between 5 and 30 l/min. Pressure and flow signals were recorded and several performance parameters, including pressure gradient, effective orifice area (EOA), insufficiency (regurgitant volume as a percent of forward flow volume) and energy loss, were computed.

Results: All sizes of the SJM Regent valve showed improved hydrodynamic performance compared with the HP valve. For the small sizes (17, 19, 21 mm), the pressure gradient of the SJM Regent decreased by 37%, 36% and 39%, respectively; the EOA increased by 22%, 22% and 21%; and the total transaortic energy loss decreased by 33%, 31% and 31% compared with the HP valve. The regurgitation for both valves ranged between 4% and 8% of forward flow volume over the 17-27 mm size range.

Conclusions: Hydrodynamic measurements confirm the gain of the SJM Regent valve over the HP valve that is expected based on the increased geometric orifice area. Given its basic similarity of design, but with an increased EOA as demonstrated in vitro, the SJM Regent valve is anticipated to provide an increased level of clinical benefit.

How to cite: Walker, D. K., Brendzel, A. M., & Scotten, L. N. (1999). The new St. Jude Medical regent mechanical heart valve: laboratory measurements of hydrodynamic performance. The Journal of heart valve disease, 8(6), 687–696.

Background and aim of the study: Several studies have demonstrated a worse performance of small prostheses in the narrow aortic root. However, modern low-profile mechanical prostheses have improved hemodynamic performance, are easy to implant, and have been used increasingly in elderly patients, where narrow roots are most frequently observed. We describe our experience in patients with aortic annuli >21 mm with the use of Medtronic Hall prostheses.

Methods: Between April 1988 and December 1997, a total of 332 patients (218 females, 114 males; mean age 59.3 +/- 9.8 years (range: 29-75 years) received Medtronic Hall size 20 (n = 140), 21 (n = 96) or 22 (n = 96) prostheses. The mean body surface area was 1.59 +/-0.12 m2 (range: 1.27-2.01 m2); 140 patients were in NYHA functional classes III/IV. There were no significant differences in clinical characteristics of patients in the three prosthesis-size groups.

Results: The mean preoperative systolic left ventricular/aorta gradient was 64.5 +/- 24.8 mmHg (no significant inter-group difference). After cardiopulmonary bypass, peak gradients through the aortic prostheses were 13.9 +/- 8.0 mmHg in size 20 valves, 14.0 +/- 8.1 mmHg in size 21, and 10.1 +/- 8.9 mmHg in size 22. Four patients died in hospital (mortality rate 1.2%); there were no significant inter-group differences in hospital morbidity. Follow up was complete for 97% of the patients (mean 4.3 years; range: 1-11 years). The late mortality rate was 9.3% (n = 31; 2.56% per pt-yr); of these patients, 20 (14.3%) had size 20 prostheses, seven (7.3%) size 21, and four (4.2%) size 22 (p = 0.01). Fourteen patients (4.2%) died from cardiac causes, and six (1.8%) from prosthesis-related causes. Preoperative older age and aortic regurgitation were the only independent predictors of late mortality. Eight patients had systemic thromboembolic events (0.66% per pt-yr), two had prosthetic thrombosis (0.17% per pt-yr) and five had hemorrhagic episodes (0.41% per pt-yr). Seven patients had prosthetic valve endocarditis (0.58% per pt-yr). Among survivors, 97% are currently in NYHA class I/II.

Conclusions: The small (size 20, 21 and 22) Medtronic Hall prostheses have good hemodynamic performance and are an excellent option as valve substitutes in patients with narrow aortic roots.

How to cite: Brazao, A. J., Prieto, D., de Oliveira, J. F., Eugenio, L., & Antunes, M. J. (1999). Aortic valve replacement with small-sized disc prostheses (medtronic hall). The Journal of heart valve disease, 8(6), 680–686.

Background and aim of the study: The long-term clinical experience of patients receiving Omnicarbon heart valve prostheses between January 1985 and December 1996 was investigated.

Methods: In total, 473 patients (255 males, 218 females; mean age 57.5 +/- 10.1 years (range: 20n-73 years) received 523 prostheses. These included 253 mitral (MVR), 170 atrial (AVR) and 50 double (DVR) valve replacements.

Results: The 30-day mortality rate was 4.7% (n = 22); in addition eight patients died more than 30 days after surgery, but during the same hospital stay. Mean follow up was 3.9 years (maximum 11 years and 7 months). Cumulative follow up was 1,750.1 patient-years (pt-yr); follow up was 97.5% complete. Among 39 late deaths, 20 were valve-related (seven cerebral infarction, seven cerebral bleeding, six endocarditis) and four cardiac-related. The overall five-year cumulative survival rate (excluding early mortality) was 90.2 +/- 11.7% (MVR 88.0 +/- 2.5%, AVR 93.1 +/- 2.3%, DVR 93.7 +/- 4.8%). At 10 years, the overall survival rate was 76.4 +/- 7.7%. Valve-related complications included thromboembolism (n = 13, 0.7%/pt-yr), anticoagulation-related hemorrhage (n = 12, 0.7%/pt-yr) and endocarditis (n = 7, 0.4%/pt-yr). Neither mechanical failure nor clinical hemolysis was observed. The overall valve-related event-free rate after five years was 89.3 +/- 2.0% (MVR 89.8 +/- 2.4%, AVR 93.5 +/- 2.6%, DVR 89.4 +/- 5.7%) and after 10 years it was 87.6 +/- 2.6% (MVR 85.4 +/- 3.7%, AVR 93.5 +/- 2.6%, DVR 82.5 +/-10.1%).

Conclusions: These long-term results with the Omnicarbon valve are excellent; especially satisfactory results were achieved in terms of the low rate of thromboembolic complication.

How to cite: Iguro, Y., Moriyama, Y., Yamaoka, A., Yamashita, M., Shimokawa, S., Toyohira, H., & Taira, A. (1999). Clinical experience of 473 patients with the omnicarbon prosthetic heart valve. The Journal of heart valve disease, 8(6), 674–679.

Background and aim of the study: Since 1986, the St. Jude Medical (SJM) mechanical heart valve prosthesis has been implanted in patients at the authors' institution. We present our experience of low-dose oral anticoagulation and antiplatelet therapy following SJM valve implantation.

Methods: Among 2,585 patients (mean age 40.3 +/- 13.5 years) living in a rural environment, 865 underwent aortic valve replacement (AVR), 1,231 mitral valve replacement (MVR) and 489 double valve replacement (DVR). All patients received 2.5 mg/day warfarin and a combination of antiaggregation therapy (dypridamole 3 x 75 mg/day plus aspirin 100 mg/day), irrespective of their prothrombin time and cardiac rhythm.

Results: Postoperatively, 139 adverse events occurred (51 in AVR patients, 58 in MVR, 30 in DVR). Operative mortality rate was 5.9%, 4.7% and 6.1%, respectively, in the three groups (overall mortality rate 5.4%). The most frequent cause of operative mortality was low cardiac output. During follow up, there were 88 anticoagulant hemorrhages (1.2%/patient-year (pt-yr)), 11 paravalvular leaks (0.2%/pt-yr), 52 thromboembolisms (0.7%/pt-yr), 60 mechanical valve thromboses (0.8%/pt-yr) and 78 reoperations (1.1%/pt-yr). These complications occurred in 101 patients after AVR, in 125 after MVR, and in 63 after DVR (4.2%, 3.7% and 4.6% per pt-yr, respectively). Patient age (p = 0.0004), concomitant surgery (p = 0.0017) and late valve-related complications (p = 0.0159) were statistically significant mortality factors after AVR. Previous surgery was a significant risk factor for operative mortality after MVR (p <0.05). Female gender (p = 0.0059) and age (p = 0.017) were significant risk factors for operative mortality after DVR (p <0.01).

Conclusions: Following implantation of the St. Jude Medical mechanical heart valve prosthesis, a fixed dose of 2.5 mg/day warfarin and combined dipyridamole/aspirin provided satisfactory results in terms of thrombosis, embolism and bleeding.

How to cite: Yamak, B., Iscan, Z., Mavitas, B., Ulus, A. T., Katircioglu, S. F., Tasdemir, O., & Bayazit, K. (1999). Low-dose oral anticoagulation and antiplatelet therapy with St. Jude Medical heart valve prosthesis. The Journal of heart valve disease, 8(6), 665–673.

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How to cite: Height, S. E., & Smith, M. P. (1999). Strategems for anticoagulant therapy following mechanical heart valve replacement. The Journal of heart valve disease, 8(6), 662–664.

Background and aim of the study: When mechanical heart valves close, they generate an impulse that is transmitted to the patient's inner ear by two routes: (i) As acoustically transmitted sound waves; and (ii) as vibrations transmitted through bones and vessels. The aim of this study was to quantitate what patients perceive as sound from their mechanical heart valve prostheses - including both air-transmitted sound waves and bone-transmitted vibrations.

Methods: Thirty-four patients with implanted mechanical bileaflet aortic and mitral valves (St. Jude Medical and On-X) were included in the study. Measurements were performed in a specially designed sound-insulated chamber equipped with microphones, accelerometers, preamplifiers and a loud-speaker. The closing sounds measured by an accelerometer on the patient's chest were delayed 400 ms, amplified and played back to the patient through the loudspeaker. The patient adjusted the feedback sound to the same level as the 'real-time' clicks they perceived directly from their valve. In this way the feedback sound energy includes both the air- and bone-transmitted energies. Sound pressure levels (SPL) were quantitated in both dB(A) and in loudness units (sones) according to ISO 532B (Zwicker method).

Results: The mean air-transmitted SPL measured close to the patient's ear was 23 +/- 4 dB(A). The total air-and bone-transmitted sounds and vibrations were perceived by the patients as a SPL of 34 +/- 5 dB(A). There was no statistically significant difference in perceived sound from the two bileaflet valves investigated, and no difference between aortic and mitral valves.

Conclusions: The study showed that the presented feedback method is capable of quantitating the perceived sounds and vibrations from mechanical heart valves, if the patient's hearing is not too impaired. Patients with implanted mechanical heart valve prostheses seem to perceive the sound from their valve two to four times higher than nearby persons, because of the additional bone-transmitted vibrations.

How to cite: Nygaard, H., Johansen, P., Riis, C., Hasenkam, J. M., & Paulsen, P. K. (1999). Assessment of perceived mechanical heart valve sound level in patients. The Journal of heart valve disease, 8(6), 655–661.

Background and aim of the study: Our clinical experience was reviewed to determine the efficacy of replacement of the atrioventricular (AV) valve for the systemic circulation in children with discordant AV connections undergoing functional biventricular repair.

Methods: Nine children underwent replacement of the morphologically tricuspid valve at the age of 10 months to 15 years. Ventriculoarterial connections were discordant in five children, and double outlet right ventricle with pulmonary stenosis or atresia in four. In all children the prosthesis chosen was a mechanical valve; valve sizes ranged from 19 mm to 31 mm.

Results: One patient died of ventricular failure immediately after surgery. Two patients underwent reoperation for re-replacement at eight and 68 months after the initial replacement because of non-structural dysfunction. Complete AV block occurred after intracardiac maneuvers in the non-survivor. Transient AV dissociation was noted in another patient. General conditions improved greatly after surgery in all survivors. In the morphologically right ventricle placed for the systemic circulation the end-diastolic volume fell from 327 +/- 182% (range: 109-621%) to 169 +/- 97% (range: 85-352%) of the anticipated normal value (p = 0.03), while pressure fell from 13 +/- 4 (range: 7-19) mmHg to 8 +/- 3 (range: 2-12) mmHg (p = 0.005). The ejection fraction was only marginally reduced (47 +/- 13% (range: 26-62%) preoperatively versus 34 +/- 11% (range: 20-54%) postoperatively; p = 0.13).

Conclusions: In children with discordant atrioventricular connections and severe regurgitation across the morphologically tricuspid valve, the valve can be efficiently replaced for the systemic circulation.

How to cite: Numata, S., Uemura, H., Yagihara, T., Kawahira, Y., Yoshikawa, Y., & Kitamura, S. (1999). Replacement of the morphologically tricuspid valve in children with discordant atrioventricular connections. The Journal of heart valve disease, 8(6), 649–654.

Background and aim of the study: Tricuspid valve replacement (TVR) is rarely undertaken, most surgeons preferring to use conservative tricuspid valve procedures. Thus, limited data are available in patients following TVR. The purpose of this study was to analyze the early and late results in 87 patients (52 tissue valves, 35 mechanical prostheses) who underwent TVR between January 1973 and September 1996.

Methods: The patient group comprised 74 (85%) females and 13 (15%) males; mean (+/- SD) age was 59.4 +/- 12.8 years; range: 15 to 81 years). Forty-four patients (51%) had undergone at least one previous cardiac operation. There were 19 (23%) isolated TVRs, 43 (49%) triple valve replacements, and 25 (29%) double valve replacements. Total cumulative follow up was 707 patient-years (pt-yr) (tissue valves 393 pt-yr, mechanical valves 314 pt-yr); mean follow up was 8.1 years (range: 0 to 23.6 years).

Results: The early (30-day) mortality rate was 10.3% (n = 9; tissue 7, mechanical 2, p = 0.28). Logistic regression identified prolonged cardiopulmonary bypass time (p <0.03) and advanced NYHA functional class (p <0.007) as risk factors for operative death. No risk factors were significant on multiple logistic regression analysis. Mean (+/- SEM) survival rate was 68 +/-5.3% (n = 50) at 5 years, 52 +/- 5.9% (n = 36) at 10 years, 35 +/- 6% (n = 20) at 15 years, and 16 +/- 5.3% (n = 7) at 20 years. Freedom from tricuspid valve reoperation at 5, 10 and 15 years was 93 +/- 3.3% (n = 46), 83 +/- 5.8% (n = 33) and 71 +/- 2.8% (n = 17) respectively. Eleven patients required tricuspid valve reoperation: six mechanical valves (five for prosthetic valve thrombosis and one for mechanical failure secondary to pannus ingrowth), and five tissue valves (two for prosthetic valve endocarditis and three for prosthetic valve degeneration). Freedom from reoperation at 5, 10 and 15 years for tissue prostheses was 97 +/- 2.5%, 89 +/- 6.3% and it was 70 +/- 12%, and 86 +/- 7.4%, 74 +/- 9.9% and 68 +/-11% for mechanical prostheses. The mechanical prostheses required reoperation earlier after the initial surgery.

Conclusions: We recommend the use of a bioprosthesis in the tricuspid position because of its initial durability and low reoperation rate.

How to cite: Dalrymple-Hay, M. J., Leung, Y., Ohri, S. K., Haw, M. P., Ross, J. K., Livesey, S. A., & Monro, J. L. (1999). Tricuspid valve replacement: bioprostheses are preferable. The Journal of heart valve disease, 8(6), 644–648.

Background and aim of study: This study was designed to determine: (i) Whether acute mitral valve regurgitation (MVR) due to chordal rupture can be reproducibly created under echocardiographic guidance; (ii) what degree of MVR can be created; (iii) what degree of acute regurgitation is survivable; and (iv) whether acute MVR due to chordal rupture progresses over time.

Methods: In a pilot group of six juvenile farm-bred sheep, selected chordae tendineae were ruptured using either a biopsy needle or endoscopic scissors under echocardiographic guidance, without need for cardiopulmonary bypass. Sheep were sacrificed acutely (n = 2), and at six weeks (n = 2) or eight weeks (n = 2). When the technique was optimized, five sheep entered a study group in which chords were ruptured using endoscopic scissors; the sheep were sacrificed 16 weeks after surgery.

Results: In the pilot study, acute MVR (grade 2-4+) was produced in all sheep, normal ventricular wall motion was maintained, with minimal progression of regurgitation over time. In one pilot sheep which did not survive, grade 4+ MVR was created acutely. Use of endoscopic scissors was preferable to the biopsy needle. In the study group, acute MVR (grade 2-4+) was produced in all five sheep, and was still present at 16 weeks, with progression in only one animal.

Conclusions: This pilot study demonstrated that controlled degrees of survivable acute MVR due to chordal rupture can be created under echocardiographic guidance, with minimal progression of MVR over time. This animal model can be applied to investigate the pathogenesis of clinical MVR, and to suggest appropriate medical or surgical intervention.

How to cite: Kunzelman, K. S., Linker, D. T., Sai, S., Miyake-Hull, C., Quick, D., Thomas, R., Rothnie, C., & Cochran, R. P. (1999). Acute mitral valve regurgitation created in sheep using echocardiographic guidance. The Journal of heart valve disease, 8(6), 637–643.

Background and aim of the study: The study aim was to determine whether re-replacement of the systemic atrioventricular (AV) valve can be achieved efficiently in children.

Methods: The systemic AV valve was re-replaced in 10 children. Initial replacement was needed for regurgitation in nine cases and congenital mitral stenosis in one case at a mean age of 3.7 +/- 3.1 years (range: 0.7-10.2 years). The initial prosthesis chosen was a mechanical valve in all cases; prosthesis size ranged from 16 mm to 27 mm. Reoperation was indicated at a mean age of 9.7 +/- 3.6 years (range: 3.5-14.8 years) because of non-structural dysfunction in five cases, prosthetic valve endocarditis in two, thrombosed valve in two, and progressive obstruction of the left ventricular outflow tract in one case. Fibrous tissues were extensively resected to enlarge the valvular orifice. A translocation maneuver was employed in five cases.

Results: Re-replacement using a bileaflet mechanical valve was successful, with no operative or late deaths. Up-sizing was feasible in six cases with the initial valve < or = 25 mm, the alternative prosthesis being 2-8 mm (mean 4.5 mm) larger than the initial one. Consecutive echocardiography demonstrated improved peak flow velocity across the AV valve (from 2.3 +/- 0.6 to 1.6 +/- 0.3 m/s). Catheterization showed improved mean pulmonary arterial pressure (from 32 +/- 13 to 21 +/- 3 mmHg). No change was seen in cardiac index (3.4 +/- 0.6 and 3.5 +/- 0.6 l/min/m2) or systemic ventricular ejection fraction (55 +/- 14% and 49 +/- 23%).

Conclusions: Re-replacement of the systemic AV valve can be achieved efficiently, even in children, with up-sizing feasible by appropriate surgical maneuvers

How to cite: Nakajima, H., Uemura, H., Yagihara, T., Kawahira, Y., Yoshikawa, Y., & Kitamura, S. (1999). Re-replacement of the atrioventricular valve for the systemic circulation in children. The Journal of heart valve disease, 8(6), 632–636.

A 64-year-old woman presented with congestive heart failure due to severe mitral valve stenosis and chronic atrial fibrillation. A Maze III procedure was performed, and the mitral valve replaced with a mitral homograft. Postoperatively, the patient regained normal sinus rhythm, had trivial mitral regurgitation, regained her atrial transport function, and had improved myocardial function.

How to cite: Khan, J. H., Foster, E. A., Intinarelli, G. M., & Merrick, S. H. (1999). Maze procedure and homograft replacement of a rheumatic mitral valve. The Journal of heart valve disease, 8(6), 630–631.

Multiplane transesophageal echocardiography (TEE) is useful in providing a detailed anatomic map for successful mitral valve repair. This report describes an approach, developed over the past two to three years, which helps to delineate valve anatomy in specific detail. Mid-esophageal views are selected to view different segments of the valve leaflets. When correlated with surgical anatomy, this approach is found to be both practical and useful.

How to cite: Shah, P. M., Raney, A. A., Duran, C. M., & Oury, J. H. (1999). Multiplane transesophageal echocardiography: a roadmap for mitral valve repair. The Journal of heart valve disease, 8(6), 625–629.

Background and aim of the study: Autologous tissue is being used more commonly for valvular repair and reconstruction, but methods for testing the mechanical properties of the tissue intraoperatively have not been available. Before committing to its use, the surgeon should know its thickness, strength, and if it is isotropic or anisotropic. We have developed an intraoperative tissue tester (ITT), based on optical and mechanical methods that allows a surgeon to assess these parameters rapidly.

Methods: Tissue thickness was measured with a micrometer. Specimens of tissue were incrementally pressurized to 200 mmHg, resulting in a dome-shaped distortion. The dome is a section of a spheroid whose dimensions are determined by the diameter of the circle and the height of the dome. The LaPlace equation for a sphere was used to calculate tissue stress. Moire fringe patterns are visualized as concentric circles or ellipses produced by directing a beam of collimated light at 450 through a grid with Ronchi rulings onto the surface of the dome. Circles indicate isotropy and ellipses indicate anisotropy. Uniaxial testing was performed on strips of tissue taken from orthogonal and intermediate axes to validate Moire fringe pattern analysis. Specimens of human pericardium (n = 8), lightly tanned by a 10-min immersion in buffered 0.625% glutaraldehyde, were examined.

Results: Mean thickness of eight specimens was 0.61 mm (range: 0.41-0.99 mm). During inflation, the lightly tanned human pericardium showed non-linear deformation characteristic of pericardium. Mean peak stress for the dome was 136 kPa. There was good correlation between dome height in the inflation tester and the uniaxial Young's modulus. Moire fringe pattern analysis showed minimal anisotropy to 200 mmHg pressure, confirmed by uniaxial testing.

Conclusions: The basic mechanical properties of autologous tissue to be used for valvular repair or reconstruction should be determined to avoid use of tissue that is outside an expected range of values for strength, anisotropy/isotropy and thickness. A self-contained ITT, based on optical and mechanical principles, has been developed to measure those parameters.

How to cite: Hanlon, J. G., Suggit, R. W., & Love, J. W. (1999). Pre-use intraoperative testing of autologous tissue for valvular surgery: a proof of concept study. The Journal of heart valve disease, 8(6), 614–624.

Background and aim of the study: A novel geometric trefoil pattern has been suggested for semilunar valve reconstruction. Optimization of the geometry must rely on an appreciation of normal anatomy and knowledge of the mechanical properties of the tissue used for the reconstruction.

Methods: Computer-assisted design (CAD) was used to create an optimized leaflet geometry based on published dimensions for normal human aortic valves. The optimized leaflet geometry was subjected to finite element analysis (FEA) to study stress distribution with pressure loading of the leaflet. In vitro function of the optimized trefoil tissue pattern is being studied by static testing initially, with physiological saline.

Results: An optimized leaflet geometry has been developed by CAD, and further refined by FEA. Static testing of the optimized trefoil tissue pattern shows near-normal anatomy, with no prolapse or pin wheeling, and full valve competence to 90 mmHg pressure.

Conclusions: An initial optimized geometry has been developed for a two-dimensional tissue pattern that can be used to reconstruct diseased semilunar heart valves with human pericardium. Optimization studies are based on the mechanical properties of the tissue, CAD to mimic normal anatomy, FEA to study stress distribution, and static load testing to confirm function.

How to cite: Hanlon, J. G., Suggit, R. W., Gibbs, E., McMeeking, R. M., & Love, J. W. (1999). Geometric optimization of a tissue pattern for semilunar valve reconstruction. The Journal of heart valve disease, 8(6), 609–613.

Background and aim of the study: Minimally invasive aortic valve replacement (AVR) has several theoretical advantages over standard median sternotomy, but the effects of these techniques on postoperative pulmonary function have not been determined.

Methods: Twenty-six patients undergoing AVR through either a ministernotomy (group M; n = 12) or a median sternotomy (group S; n = 14) underwent pulmonary function tests. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), PaO2 and PaCO2 were determined preoperatively and before hospital discharge (at a mean of five days). Data regarding time to extubation, degree of pain and opening of the pleura were collected prospectively. Both groups had similar preoperative characteristics.

Results: There was a significant decrease in FVC, FEVJ, PaO2 and PaCO2 during the postoperative period in all patients, though differences between the groups were not significant. Patients in group M referred less pain than those in group S. In this group, the fall in FVC and FEV1 correlated with the degree of pain, while preoperative FVC correlated with early extubation. Pleurotomy did not affect pulmonary function or pain.

Conclusion: FVC, FEV1, PaO2 and PaCO2 are reduced significantly following AVR, but a minimally invasive approach does not prevent postoperative pulmonary dysfunction.

How to cite: Aris, A., Camara, M. L., Casan, P., & Litvan, H. (1999). Pulmonary function following aortic valve replacement: a comparison between ministernotomy and median sternotomy. The Journal of heart valve disease, 8(6), 605–608.

Background and aim of the study: Minimally invasive aortic valve replacement (AVR) has several theoretical advantages over standard median sternotomy, but the effects of these techniques on postoperative pulmonary function have not been determined.

Methods: Twenty-six patients undergoing AVR through either a ministernotomy (group M; n = 12) or a median sternotomy (group S; n = 14) underwent pulmonary function tests. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), PaO2 and PaCO2 were determined preoperatively and before hospital discharge (at a mean of five days). Data regarding time to extubation, degree of pain and opening of the pleura were collected prospectively. Both groups had similar preoperative characteristics.

Results: There was a significant decrease in FVC, FEVJ, PaO2 and PaCO2 during the postoperative period in all patients, though differences between the groups were not significant. Patients in group M referred less pain than those in group S. In this group, the fall in FVC and FEV1 correlated with the degree of pain, while preoperative FVC correlated with early extubation. Pleurotomy did not affect pulmonary function or pain.

Conclusion: FVC, FEV1, PaO2 and PaCO2 are reduced significantly following AVR, but a minimally invasive approach does not prevent postoperative pulmonary dysfunction.

How to cite: Aris, A., Camara, M. L., Casan, P., & Litvan, H. (1999). Pulmonary function following aortic valve replacement: a comparison between ministernotomy and median sternotomy. The Journal of heart valve disease, 8(6), 605–608.

Background and aims of the study: The potential advantages of the Ross procedure in children under 10 years of age have yet to be validated. Concerns remain regarding progressive dilatation of the pulmonary autograft and potential homograft stenosis. We present our experience in this age population.

Methods: A retrospective analysis of aortic root replacement using the Ross procedure in 11 young children (nine males, two females; median age 84 months; range 3 months to 10 years) between January 1996 and January 1999 was performed jointly in two pediatric surgical centers.

Results: There were no operative deaths. Mean hospital stay was 12 +/- 4 days, and mean follow up 14.5 +/- 8 months. The event-free survival (death, reoperation, endocarditis, arrhythmia) was 100%. Currently, nine children are in NYHA functional class I, and two in class II. The autograft and homograft were evaluated by serial echocardiography. There was no sign of progressive dilatation of the autograft. Aortic regurgitation was trivial in four children and mild in seven. No growth of the autograft was noted; this was consistent with minimal somatic growth. Homograft peak gradients remained low during the follow up.

Conclusions: Although the pulmonary autograft procedure is more complex than other types of aortic valve replacement, it can be safely applied in children. Early follow up indicates satisfactory performance of the autograft. If dilatation will not occur, pulmonary root autograft may be an attractive substitute for diseased aortic valves in children.

How to cite: Vitale, N., Hornung, T., Ciotti, G., Hamilton, J. R., Pozzi, M., & Hasan, A. (1999). The Ross procedure in children under ten years of age. The Journal of heart valve disease, 8(6), 601–604.

Background and aim of the study: The root replacement (RR) method for insertion of the pulmonary autograft (PA) has resulted in improved immediate aortic valve competence. However, the unsupported pulmonary artery wall is thinner, more elastic, and thus more prone to dilatation than the normal aortic root. This might predispose to late aortic regurgitation (AR) due to splaying of the aortic commissures, similar to the mechanism of AR in Marfan's syndrome.

Methods: A fully supported root replacement (FSRR) method was designed and implemented in 78 patients, with preservation of the aortic root and proximal ascending aortic remnant fully to surround and support the PA root. Additional aortic annulus reduction was performed in 29 patients, and adjustment of the sinotubular diameter in 27.

Results: Seventy-eight patients were analyzed with sequential Doppler echocardiography. The maximal neoaortic sinus diameter remained constant for up to three years after surgery (mean 34.3 +/- 4.0 mm) compared with before surgery (35.2 +/- 4.0 mm). There was one early death, no late deaths or reoperations, and at last follow up AR was nil/trivial in 72% of patients, mild in 27% and moderate in 1%. There was no progression of AR over four years' follow up. By comparison, four patients previously underwent unsupported RR for insertion of the PA; in these patients, mean neoaortic sinus diameter increased significantly from 31 +/- 6 mm to 41 +/- 3 mm at three years after surgery (p = 0.005).

Conclusions: Insertion of the PA using a FSRR method prevents dilatation of the neoaortic sinuses and sinotubular junction without need for prosthetic material, and provides similar results to conventional RR with regard to aortic valve competence. Retaining the advantages of RR in this manner and maintaining aortic root size may prove valuable in the longer term.

How to cite: Skillington, P. D., Fuller, J. A., Grigg, L. E., Yapanis, A. G., & Porter, G. F. (1999). Ross procedure. Inserting the autograft using a fully supported root replacement method; techniques and results. The Journal of heart valve disease, 8(6), 593–600.