Micro cost-effectiveness analysis of standard vs. mini percutaneous nephrolithotomy A single Canadian institution's experience.

INTRODUCTION: Mini-percutaneous nephrolithotomy (mPCNL ) has been described as an alternative to standard nephrolithotomy (sPCNL ) for select stones. Studies suggest that mPCNL has comparable stone-free rates, with potential for decreased complications and shorter hospital stay. Costs associated with both procedures present a challenge to Canadian institutions due to capital acquisitions of equipment and ongoing disposables. The objective of this study was to compare the cost-effectiveness of both procedures at our institution. METHODS: A decision tree analytic model was developed to compare costs and outcomes of both procedures. Primary outcomes included assessment of total capital, operative, and hospitalization costs. Cost and outcome of peri- and postoperative parameters were obtained using a retrospective analysis of 20 mPCNL and 84 sPCNL procedures on 1-2.5 cm stones between January 2020 and June 2022, and supplemented with internal hospital expenditure records and literature outcome data. Descriptive statistics and regression models were performed. RESULTS: The estimated total cost-per-patient was $7427.05 and $5036.29 for sPCNL and mPCNL, respectively, resulting in cost-savings of $2390.76 in favor of mPCNL, with a comparable stone-free rate. The savings were due to lower costs associated with complications and hospital stay. mPCNL had higher capital costs ($95 116.00) compared to sPCNL ($78 517.00), but per-procedure operative costs were lower for mPCNL ($2504.48) compared to sPCNL ($3335.72). Cost-per-case regression of total costs intersected at 5.51 cases when accounting for operative and hospitalization costs, and at 20 cases when only considering operative costs. CONCLUSIONS: Despite higher upfront costs, mCPNL may represent a valid, cost-effective alternative to sPCNL for select stones due to clinical and economic benefits in Canadian institutions.

Evaluation of class II cystic renal masses proposed in Bosniak classification version 2019: a systematic review of supporting evidence.

PURPOSE: The Bosniak classification of cystic renal masses version 2019 (v.2019) includes an expanded number of types of masses in class II; such masses are considered benign in clinical practice. Data supporting these additions have not been well-documented. We aim to determine the proportion of malignant or probably malignant renal masses among the types added to Bosniak v.2019 class II. METHODS: Multiple databases were searched for studies evaluating the proportion of malignant or probably malignant renal masses among new Bosniak v.2019 class II types, four for CT and two for MRI. Risk of bias and applicability was assessed using the QUADAS-2 tool. RESULTS: Ten studies (2068 renal masses) met inclusion criteria. Among the four added class II types at CT, the proportion of malignancy among (1) 'homogeneous hyperattenuating (≥ 70 HU) masses at unenhanced CT' was 0% (0/32) in three studies; (2) 'homogeneous masses - 9 to 20 HU at unenhanced CT' was 0% (0/1454) in two studies, and (3) 'homogeneous masses 21 to 30 HU at portal-venous phase CT' was 0% (0/454) in four studies. Masses that are homogeneous, have low attenuation, and are too small to characterize on CT had no supportive evidence. Among the two added class II types at MRI, the proportion of malignancy among (1) 'homogeneous masses markedly hyperintense at unenhanced T2-weighted MR imaging (similar to CSF) was 0% (0/72) in one study, and (2) 'homogeneous masses markedly hyperintense at T1-weighted MR imaging (~ 2.5 × renal parenchyma signal intensity)' was 0% (0/32) and 5% (2/37) in two studies. Nine studies were at risk of bias within at least one QUADAS-2 domain. CONCLUSION: The addition of six types of cystic renal masses to Class II in the Bosniak v.2019 proposal may be justified but based on limited evidence, with no evidence for 'homogeneous low attenuation masses that are too small to characterize' on CT, and thus considering them benign is in part based on expert opinion. Protocol Registration: PROSERO CRD42020196408.

Study of alpha hemoglobin stabilizing protein expression in patients with ß thalassemia and sickle cell anemia and its impact on clinical severity.

UNLABELLED: The α hemoglobin stabilizing protein (AHSP) binds α-Hb and prevents its precipitation limiting free α-Hb toxicities. Our aim was to study AHSP expression in ß thalassemia syndromes in relation to their clinical severity and to compare it with its level in sickle cell anemia. We compared patients with ß-thalassemia (n=37) (ß-thalassemia major (BTM) (n=19) and ß-thalassemia intermedia (BTI) (n=18)) with 12 patients with sickle cell anemia as regards clinical severity, age at presentation, transfusion dependency, mean pre-transfusion hemoglobin level, use of hydroxyurea and AHSP expression by real time quantitative PCR. Median (and IQR) AHSP expression was significantly higher in patients with sickle cell anemia 2275 (3898) compared to thalassemia 283 (718), P=0.001, with no significant difference between BTM and BTI (P=0.346). It was also significantly higher in non-transfusion dependent patients with ß thalassemia (NTDT) compared to transfusion dependent ones (P=0.019), and in patients on hydroxyurea therapy (P<0.001). However, there was no significant difference in its level according to clinical severity score (P=0.946) or splenectomy status (P=0.145). CONCLUSION: AHSP expression was higher in patients with sickle cell anemia versus thalassemia, with no significant difference between BTM and BTI. Expression was higher in patients with NTDT and on hydroxyurea therapy.

Pulse cyclophosphamide inadequately suppresses reoccurrence of minimal change nephrotic syndrome in corticoid-dependent children.

BACKGROUND: In minimal change nephrotic syndrome (MNCS), the most common primary nephrotic syndrome in children, approximately 95% of cases show excellent responses to steroid therapy. However, responding patients may become steroid dependent and experience serious side effects. Although oral cyclophosphamide has been recommended in these patients, long-term side effects such as gonadal toxicity are an important concern. Therefore, cyclophosphamide pulses given intravenously may provide an option that maintains remission with less-frequent side effects. METHODS: We treated 20 primary steroid-dependent MCNS patients (15 boys and five girls) with intravenous cyclophosphamide. The patients were children with ages ranging from 3 to 15 years of age. Remission was induced by steroids followed by cyclophosphamide at a dose of 500 mg/m2 body surface area per month for 6 months. During this period, we attempted to completely withdraw steroids and maintain patients on cyclophosphamide alone. We monitored the patients for the occurrence of relapse and side effects during this period and for an additional 6 months after withdrawal of cyclophosphamide. RESULTS: At the end of the 6-month cyclophosphamide treatment period (i.e. 4 months after steroid discontinuation), nine patients (45%) were in remission on cyclophosphamide alone. However, patients that maintained treatment-free remission (cyclophosphamide responders) decreased to five (25%), two (10%) and one (5%) at 6 months, 1 year and 2 years, respectively. CONCLUSION: We found that a 6-month course of pulse cyclophosphamide produced unfavourable effects in the majority of paediatric patients with steroid-dependent nephrotic syndrome.

Levamisole: adjunctive therapy in steroid dependent minimal change nephrotic children.

In children with minimal change nephrotic syndrome (MCNS), the steroid dependent group constitutes an especially difficult case for management. Patients in this group are prone to serious steroid side effects. Additionally, alkylating agents commonly fail to maintain remission and expose patients to more side effects. Therapy with the immunostimulant drug levamisole may therefore be another option in the attempt to maintain remission with minimal side effects. We prospectively treated 20 of our steroid dependent primary MCNS patients with levamisole. All patients were children, with an age range of 3-15 years; 16 were boys and 4 were girls. Remission was firstly induced by steroids, then levamisole was added in a dose of 2.5 mg/kg body weight on alternate days for 6 months. During this period we attempted to withdraw steroids completely and maintain patients on levamisole alone. We followed up our patients for the occurrence of relapse and side effects during this period and for a further 6 months after stopping levamisole. In 11 out of 20 children (55%), we successfully stopped steroids for more than 2 weeks. At the end of the 6-month treatment period (i.e. after 4 months of steroid discontinuation), ten patients (50%) were maintaining remission on levamisole alone. At the end of the 12-month study period (i.e. after 6 months of levamisole discontinuation), five patients (25%) were still in remission without any treatment for the previous 6 months. No significant side effects were reported during levamisole therapy. None of the patients developed neutropenia, but the leukocyte count showed a significant reduction in those who responded to levamisole treatment. We concluded that levamisole therapy for 6 months is a safe and perhaps effective therapy in a subset of children with steroid dependent MCNS to enable an otherwise infeasible withdrawal of steroids. This may be worth a trial before other types of more hazardous adjunctive therapies are considered.