Mini-sternotomy for aortic valve surgery

In the recent years more and more efforts have been made widely to introduce new techniques in the minimally invasive cardiac surgery. At our Department and the Link?ping University Hospital, Cardiothoracic Surgery Department, from August 1996 to January 1997, aortic valve surgery was performed in 23 adult patients (9 female, 14 male), age 28-86 years (mean age 62.5 years). Twenty-two patients had aortic valve replacement, among these, in 3 cases concomitant aortic annulus dilatation was made and in one case reduction-plasty of the dilated ascending aorta. In another one case resection of a sub-aortic membrane was performed. The operations and postoperative period were free of complications in all patients. Following an average 36 hours intensive care all patients were discharged after an average of 11.2 day hospital stay. The authors introduce the new surgical technique and present its advantages and disadvantages. Mini-sternotomy has less detrimental structural and functional effects on the thorax. Moreover, due to its minimal surgical trauma, this less invasive technique reduces patient morbidity, hospital stay and cost of care. Since mini-sternotomy is a safe and advantageous technique, the authors recommend applying this new technique in most of aortic valve operations.     

Thirty years experience with heart valve surgery: isolated mitral valve replacement

BACKGROUND: Thirty years have elapsed since the commencement of open-heart surgery in South Australia. A retrospective study was performed to evaluate mortality and complication rates and to identify factors associated with poor outcomes in all patients who underwent prosthetic mitral valve replacement during this period. METHODS: Questionnaires and personal contact have been used to generate a combined database of pre-operative and post-operative information and long-term follow-up on 938 patients who underwent isolated prosthetic mitral valve replacement at the Cardio-Thoracic Surgical Unit of the Royal Adelaide Hospital between 1963 and 1993. RESULTS: Complete survival follow-up data were obtained for 92% (865) of the patients. The Starr-Edwards valve was used in 95% (891) of the patients, a Bjork-Shiley prosthesis in 2.5% (23) of the patients, and only 24 (2.5%) other valves were inserted. The hospital mortality rate for the 30-year period was 4.7%. The mean age of the patients who underwent surgery was greater in each of the three successive decades. A long-term survival advantage was observed for patients with mitral stenosis, however, survival was significantly shorter for patients with higher New York Heart Association (NYHA) functional classifications and for patients in pre-operative atrial fibrillation. Pre-operative dyspnoea was significantly improved following mitral valve replacement. The rates of postoperative haemorrhagic and embolic complications were low by comparison with other published series. CONCLUSION: Mitral valve recipients do not regain a normalized life expectancy, but risk factors that determine long-term survival can be identified pre-operatively to aid appropriate patient selection.     

Allograft valves for aortic and mitral valve replacement

OBJECTIVE: To evaluate nuclear grading on fine needle cytopunctures of breast carcinoma, which is of special interest when neoadjuvant chemotherapy is planned. STUDY DESIGN: In a prospective study, we compared cytologic grading, based on nuclear parameters (pleomorphism and mitosis), to modified Scarff-Bloom-Richardson histologic grading in 105 primary operable breast carcinomas. The results of these two nuclear grading systems were compared to Feulgen image analysis data from the corresponding cytologic samples. RESULTS: The concordance rate between the two grading systems was 76%. Concordance between cytologic and histologic grading was observed more frequently in purely invasive carcinomas (85%) than in cases combining invasive and in situ components (56%). A highly significant relationship was observed between the two grading systems and indices of proliferative activity (S-phase fraction, proliferation index, 5c exceeding rate and endoreduplication rate), particularly in concordant grading. Furthermore, nuclear area correlated with the results of the two grading systems. CONCLUSION: Cytologic nuclear grading appeared to be a reliable tool for a large proportion of breast tumors. Despite difficulties related to tumor heterogeneity, which could be detected by careful cytologic examination, it is a useful alternative to histologic grading.     

Regression of left ventricular hypertrophy after aortic valve replacement for aortic stenosis with different valve substitutes

OBJECTIVE: Stentless biologic aortic valves are less obstructive than stented biologic or mechanical valves. Their superior hemodynamic performances are expected to reflect in better regression of left ventricular hypertrophy. We compared the regression of left ventricular hypertrophy in 3 groups of patients undergoing aortic valve replacement for severe aortic stenosis. Group I (10 patients) received stentless biologic aortic valves, group II (10 patients) received stented biologic aortic valves, and group III (10 patients) received bileaflet mechanical aortic valves. METHODS: Echocardiographic evaluations were performed before the operation and after 1 year, and the results were compared with those of a control group. Left ventricular diameters and function, left ventricular wall thickness, and left ventricular mass were assessed by echocardiography. RESULTS: Group I patients had a significantly lower maximum and mean transprosthetic gradient than the other valve groups (P = .001). One year after operation there was a significant reduction in left ventricular mass for all patient groups (P < .01), but mass did not reach normal values (P = .05). Although the rate of regression in the interventricular septum and posterior wall thickness differed slightly among groups, their values at follow-up were comparable and still higher than control values (P = .002). The ratio between interventricular septum and posterior wall and the ratio between wall thickness and chamber radius did not change significantly at follow-up. CONCLUSIONS: Because the number of patients was relatively small, we could not use left ventricular mass regression after I year to distinguish among patients undergoing aortic valve replacement for aortic stenosis by means of valve prostheses with different hemodynamic performances.     

Combined tracheal resection and aortic valve replacement with a cryopreserved aortic valve allograft

A 69-year-old patient presented with an association of tracheal squamous cell carcinoma and severe aortic valve stenosis. As there was no evidence of metastatic spread a potentially curative resection could be considered. The patient underwent tracheal resection and aortic valve replacement in a one-stage procedure. In light of the potential risk of infection to a prosthetic valve, a cryopreserved aortic valve homograft was implanted. The patient made a full recovery and is doing well after 2 years of follow-up.     

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.     

Venous gangrene of the lower limbs following aortic valve replacement for native valve endocarditis

Single-shot spin-echo diffusion-weighted echo-planar imaging using a phased-array multicoil was performed to distinguish between normal and cirrhotic livers. Sets of 6 images with different b-values were acquired with breath-holding. Significant differences were observed between controls and cirrhosis cases in the signal ratios when the b-value was 383 s/mm2, and apparent diffusion coefficients.     

Meralgia paresthetica after aortic valve surgery

We report a case of meralgia paresthetica, a rare neurological complication, following aortic valvuloplasty. Although this complication was previously described after coronary artery bypass surgery, we believe this is the first case described after a valve procedure and hypothesize on its etiology.     

Risk of reoperative valve replacement for failed mitral and aortic bioprostheses

BACKGROUND: One factor influencing the choice of mechanical versus bioprosthetic valves is reoperation for bioprosthetic valve failure. To define its operative risk, we reviewed our results with valve reoperation for bioprosthetic valve failure. METHODS: Records of 400 consecutive patients having reoperative mitral, aortic, or mitral and aortic bioprosthetic valve replacement from January 1985 to March 1997 were reviewed. RESULTS: Reoperations were for failed bioprosthetic mitral valves in 219 patients, failed aortic valves in 153 patients, and failed aortic and mitral valves in 28 patients. Including 26 operations (6%) for acute endocarditis, 153 operations (38%) were nonelective. One hundred nine patients (27%) had other valves repaired or replaced, and 72 (18%) had coronary bypass grafting. The incidence of death in the mitral, aortic, and double-valve groups was respectively, 15 (6.8%), 12 (7.8%), and 4 (14.3%); and the incidence of prolonged postoperative hospital stay (>14 days) was, respectively, 57 (26.0%), 41 (26.8%), and 8 (28.6%). Only 7 of 147 patients (4.8%) having elective, isolated, first-time valve reoperation died. Multivariable predictors (p < 0.05) of hospital death were age greater than 65 years, male sex, renal insufficiency, and nonelective operation; and predictors of prolonged stay were acute endocarditis, renal insufficiency, any concurrent cardiac operation, and elevated pulmonary artery systolic pressure. CONCLUSIONS: Reoperative bioprosthetic valve replacement can be performed with acceptable mortality and hospital stay. The best results are achieved with elective valve replacement, without concurrent cardiac procedures.     

Improvement in mitral regurgitation after aortic valve replacement

This study sought to determine whether there is a quantitative improvement in mitral regurgitation (MR) after aortic valve replacement (AVR) for aortic stenosis (AS) and, if so, the mechanisms for this change. MR frequently accompanies AS. The addition of mitral valve replacement to AVR significantly increases the risk of surgery. Although previous studies have suggested a qualitative improvement in MR severity after AVR, semiquantitative analysis of this improvement has not been documented nor have the underlying mechanisms been examined. We evaluated 28 patients who had undergone 2-dimensional echo and color flow Doppler imaging an average of 1.5 +/- 2.5 months before and 2.5 +/- 4.2 months after AVR. Maximum MR area, MR percentage (MR area/left atrial area), mitral annular area, left atrial area, aortic gradient, and parameters of left ventricular geometry were measured to evaluate MR severity and to assess functional mechanisms for improvement in MR. There was a significant decrease in MR area (5.5 +/- 2.8 cm2 vs 2.5 +/- 1.9 cm2, p < or =0.0001) and MR percentage (25 +/- 11% vs 12 +/- 10% after operation, p < or =0.0001) between preoperative and postoperative studies. There was a significant reduction in aortic gradient, mitral annular area, left atrial area, and left ventricular length postoperatively. In univariate analysis, MR improvement was related to the lower preoperative left ventricular fractional area change (p = 0.027) and to the changes in fractional area change (p = 0.001) and left ventricular systolic area (p = 0.001). Thus, improvement in MR after AVR is related to changes in left ventricular function postoperatively. These data suggest that reduction in MR is due not only to decreased intraventricular pressure, but also to changes in ventricular morphology.     

Demographic characteristics of patients undergoing aortic valve replacement for stenosis: relation to valve morphology

Mucoid enteropathy is a serious disease of rabbits, the cause of which is unknown. Ligation of the cecum has been reported to cause a mucoid enteropathy-like syndrome in 70% of conventional rabbits. The goal of this study was to evaluate this model of mucoid enteropathy in Pasteurella-free, coccidia-free rabbits for use in future studies. Five rabbits served as unoperated controls (group 1). Eight rabbits underwent ligation of the cecum, with large vessels and nerves spared (group 2). In six rabbits the distal branch of the ileocecocolic vessels and nerve were incorporated into the cecal ligature (group 3). At necropsy 3 to 5 days after surgery, all group-3 rabbits had copious amounts of clear, gelatinous mucus in the colon. Only one group-2 rabbit had grossly evident mucus hypersecretion, whereas none of the group-1 rabbits did. Group-3 rabbits had areas of necrosis in the cecum; this was not seen in group-1 or group-2 rabbits. Rabbits of groups 2 and 3 had inflammation of the distal portion of the colon. In specific-pathogen-free rabbits cecal ligation alone did not reliably stimulate mucus hypersecretion but induced a disease similar to natural mucoid enteropathy. Cecal ligation including vessels provided a reproducible syndrome of mucus hypersecretion; however, the severe cecal necrosis was not consistent with the naturally acquired disease.