Potential risk of hyponatremia using histidine-tryptophan-ketoglutarate solution during pediatric cardiopulmonary bypass

Single-Dose St. Thomas Versus Custodiol® Cardioplegia for Right Mini-thoracotomy Mitral Valve Surgery

OBJECTIVE

Custodiol® and St. Thomas cardioplegia are widely employed in mini-thoracotomy mitral valve (MV) operations. One-dose of the former provides 3 h of myocardial protection. Conversely, St. Thomas solution is usually reinfused every 30 min and safety of single delivery is unknown. We aimed to compare single-shot St. Thomas versus Custodiol® cardioplegia.

METHODS

Primary endpoint of the prospective observational study was cardiac troponin T level at different post-operative time-points. Propensity-weighted treatment served to adjust for confounding factors.

RESULTS

Thirty-nine patients receiving St. Thomas were compared with 25 patients receiving Custodiol® cardioplegia; cross-clamping always exceeded 45 min. No differences were found in postoperative markers of myocardial injury. Ventricular fibrillation at the resumption of electric activity was more frequent following Custodiol® cardioplegia (P = .01).

CONCLUSION

Effective myocardial protection exceeding 1 h of ischemic arrest can be achieved with a single-dose St. Thomas cardioplegia in selected patients undergoing right mini-thoracotomy MV surgery.

Comparable prognosis in different neonatal histidine-tryptophan-ketoglutarate dosage management

Background:

Histidine-tryptophan-ketoglutarate (HTK) is a solution commonly used for organ transplantation. However, there is no certified fixed regimen for on-pump heart surgery in neonates. We aimed to retrospectively evaluate the outcomes related to different HTK dosages and to analyze the safety of high-dosage perfusion.

Methods:

A total of 146 neonates who underwent on-pump heart surgery with single-shot HTK perfusion were divided into two groups according to HTK dosages: a standard-dose (SD) group (n = 63, 40 mL/kg < HTK ≤ 60 mL/kg) and a high-dose (HD) group (n = 83, HTK >60 mL/kg). Propensity score matching (PSM) was performed to control confounding bias.

Results:

The SD group had a higher weight (3.7 ± 0.4 vs. 3.4 ± 0.4 kg, P < 0.0001), a lower proportion of complete transposition of the great artery (69.8% vs. 85.5%, P = 0.022), a lower cardiopulmonary bypass (CPB) time (123.5 [108.0, 136.0] vs. 132.5 [114.8, 152.5] min, P = 0.034), and a lower aortic x-clamp time (82.9 ± 27.1 vs. 95.5 ± 26.0 min, P = 0.005). After PSM, 44 patients were assigned to each group; baseline characteristics and CPB parameters between the two groups were comparable. There were no significant differences in peri-CPB blood product consumption after PSM (P > 0.05). The incidences of post-operative complications were not significantly different between the two groups. There were no significant differences in ventilation time, intensive care unit stay, and post-operative hospital stay (P > 0.05). Follow-up echocardiography outcomes at 1 month, 3 to 6 months, and 1 year showed that left ventricular ejection fraction and end-diastolic dimension were comparable between the two groups.

Conclusions:

In neonatal on-pump cardiac surgery patients, single-shot HD (>60 mL/kg) HTK perfusion had a comparable heart protection effect and short-term post-operative prognosis as standard dosage perfusion of 40 to 60 mL/kg. Thus, this study provides supporting evidence of the safety of HD HTK perfusion.

Acute isotonic hyponatremia after single dose histidine-tryptophan-ketoglutarate cardioplegia: an observational study

INTRODUCTION

Histidine-tryptophan-ketoglutarate cardioplegia is used for prolonged myocardial protection in complex cardiac surgery. Administration leads to acute hyponatremia in a majority of patients, because of its low sodium concentration (15 mmol/L). However, histidine-tryptophan-ketoglutarate solution's osmolality is slightly hypertonic (310 mOsm/kg). Hypothesized was that acute isotonic hyponatremia will be induced, which does not need to be corrected with hypertonic saline.

METHODS

Cardiac surgery patients who received histidine-tryptophan-ketoglutarate cardioplegia were included in this prospective single center study. Serial blood samples were taken from each patient at five different time points: after induction of anesthesia (T1) and 10 minutes (T2), 6 hours (T3), 12 hours (T4), and 18 hours (T5) after administration of histidine-tryptophan-ketoglutarate cardioplegia, respectively. Blood samples were analyzed for sodium concentration, osmolality, and acid-base balance.

RESULTS

Twenty-five patients were included. Median blood sodium levels decreased from 140 [138-141] at T1 to 128 [125-130] mmol/L at T2 (p < 0.001). At T3, T4, and T5, median blood sodium concentrations were 136 [134-138], 139 [137-140], and 140 [137-142] mmol/L, respectively. Median osmolality was 289 [286-293] at T1 and increased to 296 [291-299] mOsm/kg (p < 0.001) at T2. At T3, T4, and T5, osmolality was 298 [292-302], 298 [294-304], and 300 [297-306] mOsm/kg, respectively. Median pH decreased from 7.38 [7.36-7.40] at T1 to 7.30 [7.27-7.32] at T2 (p < 0.001).

CONCLUSION

Administration of histidine-tryptophan-ketoglutarate cardioplegia during cardiac surgery leads to acute moderate to severe isotonic hyponatremia, which resolves spontaneously in the first 18 hours perioperatively. Correction with hypertonic saline is not necessary.

Safe cross-clamp time using Custodiol®-histidine-tryptophan-ketoglutarate cardioplegia in the adult

INTRODUCTION

Safe cross-clamp time using single-dose Custodiol^®-histidine-tryptophan-ketoglutarate cardioplegia has not been established conclusively.

METHODS

Immediate post-operative outcomes of 1,420 non-consecutive, cardiac surgery patients were reviewed retrospectively. Predictors of a combined endpoint made of in-hospital mortality and any major complication post-surgery were found with the multivariable method. Analysis of variance was used to evaluate the impact of cross-clamp time on most relevant complications. Discriminatory power and cut-off value of cross-clamp time were established for in-hospital mortality and each of the major complications (receiver operating characteristic curve analysis). A comparative analysis (with propensity matching) with multidose cold blood cardioplegia on in-hospital mortality post-surgery was performed in non-coronary surgery patients.

RESULTS

Coronary, aortic valve and mitral valve surgery and surgery on thoracic aorta were performed in 45.4%, 41.9%, 49.5%, 20.6% of cases, respectively. In-hospital mortality and the rate of any major complication post-surgery were 6.5% and 41.9%, respectively. Cross-clamp time had significant impact on in-hospital mortality and almost all major post-operative complications, except neurological dysfunctions (p = 0.084), myocardial infarction (p = 0.12) and mesenteric ischaemia (p = 0.85). Areas under the receiver operating characteristic curve and the optimal cut-off values for in-hospital mortality and any major complication were of 0.657, 0.594, >140 and >127 minutes, respectively. Comorbidities-adjusted odds ratio for any major complication of cross-clamp time <127 minutes was 1.86 (p < 0.0001). Despite similar in-hospital mortality (p = 0.57), there was an earlier significant increase of mortality in Custodiol-HTK than in multidose cold blood propensity-matched, non-coronary surgery patients.

CONCLUSIONS

The use of Custodiol-HTK cardioplegia is associated with a low risk of serious post-operative complications provided that cross-clamp time is of 2 hours or less.

Safety of Single-Dose Histidine-Tryptophan-Ketoglutarate Cardioplegia during Minimally Invasive Mitral Valve Surgery

Objective

Minimally invasive mitral valve surgery may require a prolonged period of myocardial ischemia. Cardioplegic solutions that necessitate a single dose for adequate myocardial protection are evoked to simplify surgery and result to be appealing in this setting. The aim of this study was to assess early outcomes after minimally invasive mitral valve surgery using one single dose of histidine-tryptophanketoglutarate solution (HTK; Custodiol) for myocardial protection.

Methods

Between February 2003 and October 2012, a total of 49 consecutive patients underwent minimally invasive mitral valve surgery using a single dose of HTK solution for myocardial protection. The patients’ mean (SD) age was 57 (14) years; the preoperative ejection fraction was normal in all cases. The mean (SD) CPB time and aortic cross-clamp time were 148 (45) minutes and 97 (45) minutes, respectively.

Results

The heart spontaneously restarted after cross-clamp removal in 37 patients (75.5%). Five patients (10.2%) required prolonged inotropic drug support. Postoperatively, no significant increase in myocardial cytonecrosis enzymes was found [mean (SD) creatine kinase isoenzyme MB, 77.14 (53.67) μg/L at 3 hours, 71.2 (55.67) μg/L at 12 hours, and 42.53 (38.38) μg/L at 24 hours)], and no ischemic electrocardiogram modifications were observed before discharge.

Conclusions

During minimally invasive mitral valve surgery, HTK solution provided excellent myocardial protection even after prolonged periods of cardioplegic arrest. The avoidance of repetitive infusions may reduce the risk for coronary malperfusion due to dislodgement of the endoaortic clamp (if used) and increase the surgeon's comfort during the procedure.

Perfusion techniques for minimally invasive valve procedures

In this paper, we present, in detail, the simplified perfusion technique that we have adopted since January 2009 and that we have utilized in 200 cases for cardiac minimally invasive valvular procedures that were performed through a right lateral mini-thoracotomy in the 3(rd)-4(th) intercostal space. Cardiopulmonary bypass was achieved by means of the direct cannulation of the ascending aorta and the insertion of a percutaneous venous cannula in the femoral vein. A flexible aortic cross-clamp was applied through the skin incision and cardioplegic arrest was obtained with the antegrade delivery of a crystalloid solution. Gravity drainage was enhanced by vacuum-assisted aspiration. There were no technical complications related to this perfusion technique that we have adopted in minimally invasive surgical procedures.

Custodiol for myocardial protection and preservation: a systematic review

INTRODUCTION

Custodiol cardioplegia is attractive for minimally invasive cardiac surgery, as a single dose provides a long period of myocardial protection. Despite widespread use in Europe, there is little data confirming its efficacy compared with conventional (blood or crystalloid) cardioplegia. There is similar enthusiasm for its use in organ preservation for transplant, but also a lack of data. This systematic review aimed to assess the evidence for the efficacy of Custodiol in myocardial protection and as a preservation solution in heart transplant.

METHODS

Electronic searches were performed of six databases from inception to October 2013. Reviewers independently identified studies that compared Custodiol with conventional cardioplegia (blood or extracellular crystalloid) in adult patients for meta-analysis; large case series that reported results using Custodiol were analyzed. Next, we identified studies that compared Custodiol with other organ preservation solutions for organ preservation in heart transplant.

RESULTS

Fourteen studies compared Custodiol with conventional cardioplegia for myocardial protection in adult cardiac surgery. No difference was identified in mortality; there was a trend for increased incidence of ventricular fibrillation in the Custodiol group that did not reach statistical significance. No difference was identified in studies that compared Custodiol with other solutions for heart transplant.

CONCLUSIONS

Despite widespread clinical use, the evidence supporting the superiority of Custodiol over other solutions for myocardial protection or organ preservation is limited. Large randomised trials are required.