Eva Germann

Effect of Prosthesis-Patient Mismatch on Long-Term Survival With Aortic Valve Replacement: Assessment to 15 Years

BACKGROUND The effect of prosthesis-patient mismatch on long-term survival after aortic valve replacement has received considerable attention but there remains controversy. This study was performed to determine the predictors of mortality after aortic valve replacement and influence of prosthesis-patient mismatch on survival. METHODS Contemporary mechanical prostheses and bioprostheses were implanted in 3,343 patients with aortic valve replacement between 1982 and 2003. The mean age was 68.06 +/- 11.20 years (median 70.06; range, 19 to 94), and the mean follow-up was 6.18 +/- 4.96 years, for a total of 20,666 years of follow-up. Prosthesis-patient mismatch was classified by effective orifice area index categories: normal (> 0.85 cm(2)/m(2)), 1,547 (46.3%); mild-to-moderate (> 0.65 cm(2)/m(2) to < or = 0.85 cm(2)/m(2)), 1,584 (47.4%); and severe (< 0.65 cm(2)/m(2)), 212 (6.3%). RESULTS The predictors of overall mortality were age, age categorization, New York Heart Association functional class III/IV, concomitant coronary artery bypass graft surgery, prosthesis type, preoperative congestive heart failure, diabetes mellitus, renal failure, and chronic obstructive pulmonary disease. All categories of effective orifice area indexes were not predictive of overall mortality, late mortality, or early mortality. The 15-year overall survival was differentiated by effective orifice area index categories: 38.1% +/- 2.1%, 37.0% +/- 2.2%, and 22.1% +/- 6.5%, respectively, for the three categories. Survival adjusted for the covariates (effective orifice area index, age, basal mass index, and ejection fraction) determined no effect except severe effective orifice area index when adjusted for ejection fraction more than 50% (p = 0.049). CONCLUSIONS Prosthesis-patient mismatch is not a predictor of overall standard unadjusted mortality to 15 years after aortic valve replacement, regardless of the category of effective orifice area index.

Reoperation in biological and mechanical valve populations: Fate of the reoperative patient

From 1975 through 1992 inclusive, reoperative valve replacement (REOP) was required by 12.9% of patients (708/5,499). Of 1,355 patients with mechanical prostheses (MP), 46 (3.4%) came to REOP versus 662 of 4,144 patients (16%) with biological prostheses (BP). Early REOP mortality rate was 17.4% (8/46) for MP and 10.6% (70/662) for BP (p = not significant). It was higher with age greater than 75 years (p < 0.05) and trended higher with concomitant procedures and with increasing number of REOPs (p = not significant). The percentage freedom from REOP at 5 and 10 years for all BP was 96.0% +/- 0.4% and 74.9% +/- 1.1% compared with 93.6% +/- 1.2% and 87.9% +/- 2.5% for MP. The most common cause of REOP in the BP patients was structural valve deterioration, which was uncommon in patients with MP (72% versus 2% of REOP but only 15% versus 0.1% of initial implants). Nonstructural dysfunction was the leading cause of REOP in the MP group (65% versus 11%). Prosthetic valve endocarditis (18% versus 10%) and thromboembolic complications (10% versus 1%) were also more frequent causes of REOP in MP patients. However, the increased relative role of these factors with MP is due to the minimal incidence of structural valve deterioration. When related to the original choice of MP versus BP, only thromboembolic complication (3.8 times) was more prevalent as a cause of REOP in patients receiving MP at their previous procedure (p = not significant). For patients who previously received BP, structural valve deterioration (69 times) was more likely to lead to REOP than with MP (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Performance of bioprostheses and mechanical prostheses assessed by composites of valve-related complications to 15 years after aortic valve replacement

OBJECTIVE Predominant concerns of patients undergoing valve replacement surgery are risks of death, stroke, antithrombotic bleeding, and reoperation related to the replacement prosthesis. The purpose of this study was to compare valve-related reoperation, morbidity (permanent impairment), and mortality between bioprostheses and mechanical prostheses for mitral valve replacement. METHODS Between 1982 and 1998, a total of 959 bioprostheses were implanted in 943 patients, and a total of 961 mechanical prostheses were implanted in 839 patients. Total follow-ups were 5730 years for bioprostheses and 5271 years for mechanical prostheses. Eight variables were considered as predictors of risk for the composites of valve-related complications. RESULTS The linearized occurrence rates for valve-related reoperation were 3.7 events/100 patient-years for bioprostheses and 0.5 events/100 patient-years for mechanical prostheses ( P < .001), with all age groups differentiated except older than 70 years. Valve-related morbidity was undifferentiated for bioprostheses and mechanical prostheses. Valve-related mortalities were 1.7 events/100 patient-years for bioprostheses and 0.7 events/100 patient-years for mechanical prostheses ( P < .001). Predictors of valve-related reoperation were age and valve type. The only predictor of valve-related morbidity was age, whereas age and valve type were predictors for valve-related mortality. Actual freedom from valve-related reoperation favored mechanical prostheses in all age groups except older than 70 years (91.7% +/- 2.0% for bioprostheses at 15 years and 96.7% +/- 1.5% at 12 years for mechanical prostheses). Actual freedom from valve-related morbidity was not different between bioprostheses and mechanical prostheses. Actual freedom from valve-related mortality favored mechanical prostheses in all groups except older than 70 years. CONCLUSION Comparative evaluation gives high priority in mitral valve replacement for mechanical prostheses relative to bioprostheses for freedom from valve-related reoperation and valve-related mortality but not valve-related morbidity. Freedom from valve-related reoperation and valve-related mortality favors mechanical prostheses for all age groups except older than 70 years. Valve-related morbidity, due to neurologic or functional impairments, does not differentiate between bioprostheses and mechanical prostheses.

Porcine bioprostheses in the elderly: Clinical performance by age groups and valve positions

Porcine bioprostheses have been recommended and used for cardiac valve replacement in the elderly. A review of 1,984 patients with 2,042 operations, performed between 1975 and 1992, has afforded a detailed evaluation of clinical performance by valve positions and age groups within the elderly population. The numbers of operations performed by age groups were 65 to 69 years, 719; 70 to 74 years, 745; 75 to 79 years, 431; 80 to 84 years, 119; and 85 years or older, 28. The early mortality rate overall was 9.5% (195 patients), range 6.9% to 17.8% by age groups (p < 0.05), and 11.9% with concomitant procedures and 7.6% without (p < 0.05). The total cumulative follow-up was 10,060 patient-years (mean, 4.9 years). The late mortality rate was 7.0%/patient-year (for age groups, 5.8% to 13.4%/patient-year) (p = not significant). The patient survival at 15 years ranged from 25% +/- 4% for 65 to 69 years to 9% +/- 5% for 75 to 79 years (p < 0.05). The freedom from valve-related complications and composites at 10 years revealed differences (p < 0.05) by age groups only for structural valve deterioration: 85% +/- 2% for 65 to 69 years versus 98% +/- 2% for 80 to 84 years. The overall freedom from structural valve deterioration at 10 years for aortic valve replacement was 98% +/- 1%; for mitral valve replacement, 79% +/- 3%; and for multiple replacement, 86% +/- 7% (p < 0.05, aortic valve replacement > mitral valve replacement).(ABSTRACT TRUNCATED AT 250 WORDS)

Tricuspid valve replacement: Porcine bioprostheses and mechanical prostheses

The clinical performance of tricuspid valve replacement with bioprostheses and mechanical prostheses was assessed in a series of 5,489 total valve replacement operations performed from 1975 to 1992. There were 97 (1.8%) tricuspid valve replacements in 94 patients (16 men, 78 women) with a mean age of 55.4 +/- 13.8 years. Bioprostheses (mean patient age, 55.9 +/- 14.1 years) were used in 83 operations and mechanical prostheses (mean patient age, 52.1 +/- 11.9 years) were used in 14 operations. There were 30 isolated tricuspid valve replacements and 67 tricuspid valve replacements incorporated in multiple valve replacements. The total cumulative follow-up was 360 patient-years (bioprostheses, 321 years; mechanical prostheses, 39 years) (96.8% complete). The mean follow-up was 3.7 years (bioprostheses, 3.9 years; mechanical prostheses, 2.8 years) (p = not significant). The early mortality was 14.4% (bioprostheses, 14.5%; mechanical prostheses, 14.3%) (p = not significant) (isolated replacement, 13.3%; multiple replacement, 14.9%). The late mortality was 9.2% per patient-year (isolated replacement, 12.2% per patient-year; multiple replacement, 7.9% per patient-year). The freedom from structural valve deterioration at 5 and 7 years was 100% for mechanical prostheses and 97.1% +/- 2.9% for bioprostheses (p = not significant). For isolated tricuspid valve replacement, the freedom from structural valve deterioration for bioprostheses was 90.9% +/- 8.7% at 5 years and at 7 years (p = not significant). For the mechanical prostheses, the freedom was 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of abdominal quilting sutures for seroma prevention in TRAM flap reconstruction : A prospective, controlled trial

This study is designed to evaluate the effect of abdominal quilting sutures on the incidence of abdominal seroma formation in patients undergoing pedicled transverse rectus abdominis musculocutaneous (TRAM) flap reconstruction. It is theorized that the use of such sutures during closure of abdominal flaps will collapse dead space, thus preventing abdominal seroma formation. A total of 71 consecutive patients undergoing pedicled TRAM flap breast reconstruction were randomly assigned to receive abdominal quilting sutures or to undergo a standard abdominal closure. Primary outcome measures included: daily drain output for the first 3 postoperative days, time to drain removal, and seroma formation. Drain output per day decreased with the use of abdominal quilting sutures; however, the time to drain removal was not significantly affected. Most importantly, there was no significant decrease in the incidence of seroma formation with the use of abdominal quilting sutures in this series.

Surgical management of acute sigmoid diverticulitis

PURPOSE To determine the frequency of use of resection and primary anastomosis in the management of acute sigmoid diverticulitis at Royal Columbian Hospital. METHODS A retrospective chart review of all patients undergoing emergency surgery for acute sigmoid diverticulitis between 1989 and 2000 at the Royal Columbian Hospital, New Westminster, BC, was carried out in order to determine the frequency of resection and primary anastomosis. Patients who underwent bowel preparation were excluded. RESULTS Ninety-seven cases met the criteria. There were 33 cases of resection and primary anastomosis (34%). Five of these cases were protected with a proximal diverting stoma giving an incidence of 85% unprotected primary anastomosis in a group of patients undergoing emergency surgery for acute sigmoid diverticulitis. There was 1 anastomotic leak, 7 wound infections, and 3 deaths with an average length of stay of 9 days. CONCLUSIONS The practice of resection and primary anastomosis for acute sigmoid diverticulitis at the Royal Columbian Hospital has an acceptable morbidity and mortality.

Intra-abdominal complications after surgical repair of small bowel injuries: an international review.

BACKGROUND The ideal method of repairing serious small bowel injuries remains unknown. Prior reports suggest a higher rate of enteric anastomotic-related complications (EACs) with stapled posttraumatic bowel anastomosis but did not specifically focus on the small bowel or clarify fully the actual anastomotic construction. METHODS This was a retrospective review of patients requiring surgical repair of small bowel perforations at a Level I urban American center (Detroit Receiving Hospital [DRH]) and a Canadian provincial trauma center (Vancouver Hospital and Health Sciences Center [VHHSC]). All patients requiring a primary repair and/or resection were included. Anastomoses were hand-sewn, stapled, or combined stapling and sewing with mucosal inversion. Leaks, anastomotic fistulae, and intra-abdominal abscesses were considered specific EACs. A sample size of 53 per group was obtained to detect a 17% difference at alpha = 0.05 (one-sided) and beta = 0.2. RESULTS Full-thickness small bowel injuries were repaired in 232 patients (DRH, 165; VHHSC, 67). Injuries were penetrating at DRH (91.5%) and blunt at VHHSC (65.7%). Anastomotic repairs in 127 patients (158 anastomotic repairs [DRH, 113; VHHSC, 55]) were 64 (40.5%) stapled, 38 (24.1%) hand-sewn, and 56 (35.4%) combined. Also, 105 patients had 349 primary closures of an injury. Overall, there were 24 EACs. After anastomosis, there were 11 intra-abdominal abscesses: 6 after stapling, 3 after being sewn, and 2 after a combined construction. There were four small bowel anastomotic fistulae: three after stapled-only anastomosis and one after hand-sewing. After enteroenterostomy, the EAC rate was 10.2% per patient, or 8.4% per anastomosis. After primary repairs, one patient had an anastomotic fistula, which closed spontaneously, and 11 had intra-abdominal abscesses, yielding an EAC rate of 10.6% per patient or 3.4% per repair. A primary repair was significantly less likely to be associated with an EAC than any anastomosis (p = 0.035). No method of anastomosis was statistically safer in relation to EACs, whether analyzed by patient, by anastomosis, or by considering primarily either the use of a linear stapler or the principle of inverting the mucosal approximation. Only damage control procedures and associated pancreaticoduodenal injuries were identified as statistically significant predictors using multiple logistic regression analysis. CONCLUSION Anastomotic complications after enteroenterostomy or primary repair for trauma are uncommon regardless of the technique, but surgeons must be especially cautious during or after damage control. Primary repairs are desirable, but when anastomosis is unavoidable, the method of repair should reflect that with which the surgeon is the most comfortable.

Carpentier-Edwards supraannular porcine bioprosthesis: second-generation prosthesis in aortic valve replacement.

BACKGROUND The Carpentier-Edwards supraannular porcine bioprosthesis experience for more than 18 years has been evaluated by actuarial and actual analysis to determine the clinical performance in aortic valve replacement. METHODS From 1981 to 1998, 1,823 patients (mean age 68.5 years, range 20 to 90 years) underwent 1,846 procedures. Previous coronary artery bypass was performed in 3.1% (56) and previous valve repair/replacement in 6.0% (110). Concomitant coronary artery bypass grafting was performed in 41.5% (756). RESULTS The overall valve-related complication rate was 4.5%/patient-year (567 patients) with a fatality rate of 0.9%/patient-year (110 patients). The patient survival, at 15 years, was 33.0%+/-3.7% for the 61 to 70 years age group and 13.5%+/-2.4% for the older than 70 years group. At 15 years, the overall actual, cumulative freedom from reoperation was 83.2%+/-1.4%, valve-related mortality was 88.0%+/-1.2%, and valve-related residual morbidity was 92.0%+/-0.8%. The actual freedom from structural valve deterioration at 15 years was 84.2%+/-2.8% for the 61 to 70 years group and 97.1%+/-0.9% for the older than 70 years group. CONCLUSIONS The Carpentier-Edwards porcine bioprosthesis provides excellent freedom from structural valve deterioration, and overall freedom from valve-related morbidity, mortality, and reoperation for aortic valve replacement for up to 15 years. The prosthesis is recommended for patients older than 70 years and for patients 61 to 70 years, especially when extended survival is not anticipated.

An evaluation of prognostic scoring systems in patients with follicular thyroid cancer

BACKGROUND Prognostic scoring systems for thyroid cancer have not been investigated in patients with pure follicular cancer; thus, the purpose of this study was to compare the following prognostic indices: the European Organization for Research and Treatment of Cancer (EORTC) method; the Age, Grade, Extent, Size (AGES) score; and the Age, Metastasis, Extent, Size (ALIES) score. PATIENTS AND METHODS A retrospective study reviewing 122 patients actively treated between 1955 and 1990 was conducted. Scoring systems were calculated and survival analysis completed. AGES low-risk patients were analyzed with respect to known risk factors. RESULTS The AGES scoring system significantly defined low- and high-risk groups (P = 0.0041); the ratio of deaths between high-versus low-risk groups was 1.9:1. EORTC scores distinguished four risk groups (P = 0.002). The AMES scoring system did not significantly assign risk. In multivariate analysis of low-risk AGES patients, age, perithyroidal tissue involvement, and positive frozen section reached statistical significance. CONCLUSIONS The AGES and EORTC scoring systems best defined low- and high-risk groups of patients with pure follicular cancer, although the separation between groups was low.