Correction of aortic regurgitation after transcatheter aortic valve implantation of the Medtronic CoreValveTM prosthesis due to a too-low implantation, using transcatheter repositioning.

BACKGROUND AND AIM OF THE STUDY: Transcatheter aortic valve implantation (TAVI) has been introduced for the treatment of severe symptomatic aortic stenosis in patients not suitable for surgical valve replacement. However, a potential problem of TAVI is the development of severe aortic insufficiency after valve implantation due to a too-low implantation of the valve. METHODS: Since August 2008, a total of 33 TAVI procedures using the 18 Fr Medtronic CoreValve ReValving system has been performed at the authors' institution. RESULTS: Severe post-implantation aortic regurgitation occurred in three patients (9%), due to a too-low implantation. Two of these patients underwent a catheter-based repositioning of the valve using a standard snare; the third patient declined any further intervention. Both repositioning procedures were uneventful, with no significant residual regurgitation. CONCLUSION: Severe aortic regurgitation after TAVI with the Medtronic CoreValve system is not uncommon. If the valve is implanted too low, a catheter-based valve repositioning may be the method of choice to resolve the problem.

Influence of two different volume replacement regimens on renal function in elderly patients undergoing cardiac surgery: comparison of a new starch preparation with gelatin.

OBJECTIVE: There is continuing concern on the influence of hydroxethyl starch (HES) on renal function. DESIGN: Prospective, randomized study. SETTING: University-affiliated medical center. PATIENTS: Forty consecutive patients aged >70 years undergoing cardiac surgery using cardiopulmonary bypass. INTERVENTIONS: Either low-molecular HES (mean molecular weight: 130 kD) with low degree of substitution (0.4) (6% HES 130/0.4) (n=20) or gelatin ( n=20) was given after induction of anesthesia until the 2nd postoperative day (POD) to keep central venous pressure between 12-14 mmHg. MEASUREMENTS AND RESULTS: Creatinine clearance (CC) and fractional sodium clearance (FSC) were measured. N-acetyl-beta-D-glucosamidase, alpha-1-microglobulin, glutathione transferase-pi, and glutathione transferase-alpha were measured from urine specimens. Measurements were made after induction of anesthesia, at the end of surgery, and at the first and the second POD. More gelatin (total: 4150+/-490 ml) than HES 130/0.4 (total: 3450+/-450 ml) was infused within the study. CC and FSC were without differences between the two groups. All measured kidney-specific proteins were almost within normal range at baseline. They increased significantly after surgery, however, without significant group differences. At the 2nd POD, kidney-specific proteins had returned almost to normal values. None of the patients developed acute renal failure. CONCLUSIONS: Sensitive markers of kidney dysfunction increased in our elderly patients indicating moderate alterations in kidney integrity during cardiac surgery. The two volume replacement regimens did not differ with regard to kidney integrity in elderly patients undergoing cardiac surgery.

Prophylactic use of the phospodiesterase III inhibitor enoximone in elderly cardiac surgery patients: effect on hemodynamics, inflammation, and markers of organ function.

OBJECTIVE: Elderly patients appear prone to develop overwhelming post-bypass inflammation and organ dysfunction. We assessed the effect of prophylactic administration of the phosphodiesterase III inhibitor enoximone on inflammation and organ function. DESIGN: Prospective, blinded, randomized, placebo-controlled study. SETTING: Clinical investigations on a surgical intensive care unit. PATIENTS: 40 consecutive patients aged over 80 years undergoing first-time coronary artery bypass grafting. INTERVENTIONS: Enoximone was given to 20 patients after induction of anesthesia (initial bolus 0.5 mg/kg) followed by a continuous infusion of 2.5 micro g/kg per minute until the 2nd postoperative day. Control patients ( n=20) received saline solution. MEASUREMENTS AND RESULTS: Interleukins 6, 8, and 10 and soluble adhesion molecules were measured. Liver function was assessed by the monoethylglycine-xylidide test and by measuring alpha-glutathione S-transferase plasma levels; splanchnic perfusion by continuous gastric tonometry; renal function by measuring creatinine and alpha(1)-microglobulin. Interleukins increased significantly more in controls than in the enoximone-pretreated patients. Soluble adhesion molecules were significantly more increased in controls. Liver function was more altered in controls than in the enoximone-pretreated patients. alpha(1)-Microglobulin increased significantly more in controls than in the enoximone group, indicating less tubular damage in the verum group. CONCLUSION: . Prophylactic use of enoximone in cardiac surgery patients aged over 80 years resulted in less post-bypass inflammation and improvement in markers of organ function than in the placebo group. The exact mechanisms by which enoximone exerts its beneficial effects in these patients remains to be elucidated.

Does coagulation differ between elderly and younger patients undergoing cardiac surgery?

OBJECTIVE: Multiple improvements allow cardiac surgery in an increasingly older population. It is still unclear whether perioperative hemostasis differs between elderly and younger patients. DESIGN: Prospective, observational study. SETTING: Single institutional study at an urban, university-affiliated hospital. PATIENTS: Twenty-one consecutive patients aged over 80 years and 21 consecutive patients aged under 60 years undergoing first-time elective aortocoronary bypass grafting. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Modified thromboelastography (TEG) using different activators [intrinsic TEG (InTEG); extrinsic TEG (ExTEG); fibrinogen TEG (fibTEG)] was carried out to measure coagulation time [CT = reaction time (r)], clot formation time [CFT = coagulation time (k)], and maximum clot firmness [MCF = maximal amplitude (MA)]. Measurements were performed before surgery, at the end and 5 h after surgery on the intensive care unit (ICU), and on the morning of the 1st postoperative day (POD). Blood loss was slightly higher in the elderly than in the younger patients. Most TEG data were already significantly different between elderly and younger patients at baseline, indicating altered coagulation in the elderly prior to surgery (hypocoagulability). After surgery and on the ICU, elderly patients showed similar alterations in TEG to those of the younger patients (e.g. InTEG-CT: from 183+/-21 to 239+/-28 s versus from 146+/-15 to 186+/-26 s). On the 1st POD, most TEG data had returned almost to baseline values, however, they were still different between elderly and younger patients. CONCLUSIONS: Elderly cardiac surgery patients already showed moderately altered coagulation prior to surgery. Thus elderly patients may be at risk of developing postoperative alterations in hemostasis on the ICU. The exact reasons for the impaired coagulation in the elderly remains to be determined.