Impact of pedicle clamping in pediatric liver resection.

BACKGROUND: Vascular clamping techniques are commonly used but so far the impact on pediatric liver surgery has not been investigated. The purpose of this study was to analyze pedicle clamping during pediatric liver resection in terms of hepato-cellular injury and blood loss. METHODS: Sixty-seven children undergoing liver resection were analyzed retrospectively. Vascular clamping was used in 28 cases (PC group), in 39 the resection was performed without clamping (NPC group). Major hepatectomies (resection of more than three segments) were carried out in 88%, minor hepatectomies (resection of three and less segments) in 12% of patients. Twenty-six children underwent extended liver resection. Patient data, liver function tests (LFTs) and blood loss were analyzed statistically. RESULTS: There were no significant differences in patient preoperative and postoperative data and LFTs between the groups. Within the NPC group the amount of administered fresh frozen plasma (FFP) in total and per kilogram (FFP/kg) was significantly higher (p=0.023 and 0.028) than in the PC group. For patients with extended liver resection, operation times were significantly longer (p=0.016) in the group without vascular clamping (NPCext). In the NPCext group significantly more children required packed red cells, FFP and FFP/kg. LFTs showed no significant differences in all children regardless of vascular clamping. CONCLUSIONS: For children undergoing liver resection, vascular clamping offers a blood saving surgical technique. Postoperative LFTs were not statistically different, regardless of vascular clamping. Pedicle clamping proved to be a safe method, not associated with an increase in perioperative complications.

P-glycoprotein modulation improves in vitro chemosensitivity in malignant pediatric liver tumors.

BACKGROUND: Multidrug resistance (MDR) is a major reason for the poor outcome of advanced pediatric liver malignancies. The P-glycoprotein (P-gP), which contributes to this phenomenon, has been potently antagonized in other tumors. Our aim was to investigate the influence of P-gP antagonizers on the chemotherapy of pediatric liver malignancies in vitro. MATERIALS AND METHODS: One hepatocellular carcinoma (HCC) and three hepatoblastoma (HB) cell lines were incubated with doxorubicin or cisplatin. Additional effects of three P-gP-modulators were determined in a cytotoxicity assay. Expression levels of the MDR1 gene were determined using rT-PCR. RESULTS: Modulation of P-gP improved chemotherapy results in all HB cell lines, more effectively in the more highly differentiated tumors. Combined treatment of the HCC cell line was only more efficient using doxorubicin and PSC 833. CONCLUSION: Modulation of P-gP can overcome MDR in HCC and HB in vitro. Our data encourage further studies analyzing this effect under in vivo conditions.

Steroid-resistant idiopathic childhood nephrosis: overdiagnosed and undertreated.

BACKGROUND: The rate of complete remission after induction therapy for steroid-resistant nephrotic syndrome (SRNS) due to either focal segmental glomerulosclerosis (FSGS) or minimal change nephrotic syndrome (MCNS) has been reported to be <50%. The present retrospective study investigated 86 children with SRNS due to FSGS and MCNS and found improved rates of complete remission in children with idiopathic FSGS and MCNS after combination therapies using ciclosporin A (CSA) and prednisolone (PRED). METHODS: Eighty-six children with FSGS or MCNS and with SRNS receiving standard oral PRED therapy were analysed in a retrospective, non-randomized study. Fifty-two patients had idiopathic FSGS (group 1), 14 patients had MCNS (group 2), and 20 patients had genetic FSGS or syndrome-associated FSGS (group 3). In group 1A (n = 25), induction therapy consisted of CSA (initial dose 150 mg/day/m(2) divided into two doses) given in combination with intravenous methylprednisolone (IV-MPRED 300-1000 mg/day/m(2) for 3-8 days) and oral PRED. In group 1B (n = 27), CSA was combined with oral PRED (40 mg/m(2) on alternate days). RESULTS: In group 1, patients with idiopathic FSGS receiving IV-MPRED + oral PRED + CSA had a significantly better outcome than patients treated with oral PRED + CSA (84 vs 64% cumulative proportion of sustained complete remission, respectively; P = 0.02, log-rank test). Sixteen (40%) out of 40 children entering complete remission had a first relapse after a median interval of 1 year. All relapses were successfully treated with IV-MPRED + oral PRED + CSA or oral PRED + CSA. Three out of forty responding children developed stage 2 chronic kidney disease (CKD), and none advanced to stage 3-5; in contrast, 9 out of 12 children with persistent nephrotic syndrome (NS) developed CKD stage 2-5 (8 vs 75%, respectively; P < 0.001, Fisher's exact test). In group 2, all 14 children with steroid-resistant MCNS went into remission after receiving PRED + CSA (n = 11) or IV-MPRED + oral PRED + CSA (n = 3). No patient developed CKD. In group 3, NS persisted in all 20 children having a genetic or syndromic type of FSGS receiving either PRED + CSA (n = 9) or PRED alone (n = 11). Seventeen out of 20 patients entered stage 5 CKD and were successfully transplanted; one patient developed recurrent NS. CONCLUSION: Prolonged and intensified treatment of children with idiopathic non-genetic SRNS (FSGS or MCNS) with combined PRED + CSA therapy including IV-MPRED pulses resulted in a higher rate of remission when compared with previous reports on using CSA mono-therapy or other immunosuppressive combination therapies.

Predictors of VT/VF-occurrence in ICD patients: results from the PROFIT-Study.

AIMS: Identification of risk factors for ventricular tachycardia/ventricular fibrillation (VT/VF) occurrence in patients with implantable cardioverter-defibrillators (ICD) is reasonable, because ICD patients with multiple risk factors might benefit from more aggressive anti-arrhythmic therapy for the prevention of arrhythmic events. Furthermore, in the era of prophylactic ICD therapy and limited healthcare resources, additional markers are needed for improved patient selection. METHODS AND RESULTS: Thus, in Prospective Analysis of Risk Factor for Appropriate ICD Therapy (PROFIT), we prospectively analyzed the role of ejection fraction (EF), N-terminal probrain natriuretic peptide (NT-proBNP), New York Heart Association (NYHA) class, atrial fibrillation, and QRS-duration as independent predictors for VT/VF occurrence in 250 ICD patients. Kaplan-Meier analysis showed that EF<40% (log-rank P=0.001), NT-proBNP levels higher than median (>or=405 ng/L; log-rank P=0.04), QRS-duration >or=150 ms (log-rank P=0.016), permanent atrial fibrillation (log-rank P=0.008), and higher NYHA class (log-rank P=0.029) were associated with VT/VF occurrence. By multivariate Cox regression analysis EF, QRS-duration and atrial fibrillation remained significantly associated with appropriate VT/VF therapy, whereas there was no relationship among NT-proBNP, NYHA class, and VT/VF occurrence. Stratifying patients according to the number of their independent risk factors (EF<40%, AF, QRS-width>or=150 ms) showed that patients with greater than or equal to two risk factors had a 100% 2-year risk of VT/VF occurrence, whereas patients with no or one risk factor had a 19.3 and 25% 2-year risk, respectively. CONCLUSIONS: EF<40%, permanent atrial fibrillation, and QRS>or=150 ms are independent predictors for VT/VF occurrence in predominantly secondary prophylactic ICD patients. Combining all independent predictors, we developed a risk score for VT/VF occurrence identifying a subgroup of patients with two or more risk factors who had a 100% 2-year risk. Future studies will reveal if this risk score helps to identify ICD patients suitable for empirical anti-arrhythmic therapy and to improve patient selection for prophylactic ICD therapy.

MDR1 modulators improve the chemotherapy response of human hepatoblastoma to doxorubicin in vitro.

PURPOSE: P-glycoprotein, a membrane efflux pump encoded by the MDR1 gene, plays an important role in the development of multidrug resistance in human hepatoblastoma (HB). Chemosensitizers antagonize the efflux action of P-glycoprotein. This study investigates the effects of 3 chemosensitizers (the cyclosporin analogue SDZ PSC 833 (PSC 833), the acridone carboxamide derivative GG 918, and verapamil) on the chemotherapy of HB in vitro. METHODS: The doxorubicin (DOXO) concentration that produces 50% growth inhibition (IC50) in a HB cell line was determined and additional effects of PSC 833, GG 918, and verapamil were investigated in a cytotoxicity assay. The MDR1 gene expression after treatment was determined in a semiquantitative reverse transcription polymerase chain reaction approach. RESULTS: The IC50 of DOXO is 2.5 microg/mL, 0.61 microg/mL for DOXO + PSC 833, 1.17 microg/mL for DOXO + verapamil, and 1.47 microg/mL for DOXO + GG 918. In combination with DOXO, cell growth was inhibited 4.1-fold by PSC 833, 2.1-fold by verapamil, and 1.9-fold by GG 918. The MDR1 gene expression was enhanced significantly in all treated cells, with and without modulator. CONCLUSIONS: MDR1 modulators significantly improve the response of HB to DOXO in vitro. The combination of anticancer agents and MDR1 modulators might be a possible contribution to overcome multidrug resistance in HB.