[Evolution from Percutaneous nephrolithotomy to Mini-PCNL in supine position on the treatment of complex renal calculi: feasibility study.] / Evolución de nefrolitotomía percutánea estándar a mini­NLP en posición supino en el tratamiento de la litiasis renal compleja: estudio de viabilidad.

OBJECTIVES: Mini-PCNL is a potentially less invasive technique than standard percutaneous nephrolithotomy (PCNL). We present our experience and results comparing both approaches in large burden complex renal calculi. METHODS: Prospective non randomized study comparing PCNL (24/26F nephroscope; Group A) and Mini-PCNL (15/18F; Group B) perioperative and postoperative results, in 40 (20 each group) consecutive patients between 2013 and 2014. We analyze demographic data, hemoglobin drop, urine culture, stone characteristics, operative time, puncture, number and size of the tract, disintegration energy sources, nephrostomy placement, hospital stay, stone free rate and Clavien-Dindo complications. RESULTS: Evolution has shown growth for Mini-PNL, with the last 17 consecutive cases performed by this approach. No preoperative differences in laterality, age, gender or ASA were found; but there were differences in BMI (median Group A: 26.35 kg/m2; Median Group B: 33.05 kg/m2, p = 0.008). Median calculi surface area (SA = length × width × π × 0.25) was higher for mini-PNL (6.69 cm2 vs 14.14; p=0.003). The operative time was longer for mini-PNL (120 vs 162.5 min, p = 0.03). Only one case (5%) required transfusion in NLP 24/26F. Mini-PCNL was associated with tubeless technique (55%) (p = 0.022), which explains lower 24 h postoperative pain, after surgery, measured by VAS (p =0.0004). The hospital stay was equivalent (median: 2 days; p=0.8). Both techniques showed efficacy (SFR at 3 months 80%). There were no statistically significant differences between the number and severity of complications between groups (Group A: 15%, 66.7% Clavien II, Group B: 15%; 66.7% Clavien II, p = 1). CONCLUSIONS: Mini-NLP can manage kidney stones and even large staghorn calculi without nephrostomy in a high percentage of patients. The technical evolution towards a small caliber approach maintains the effectiveness of the procedure without impacting its safety, with benefits perceived by patients such as less postoperative pain.

Evolución de nefrolitotomía percutánea estándar a mini-NLP en posición supino en el tratamiento de la litiasis renal compleja: estudio de viabilidad / Evolution from Percutaneous nephrolithotomy to Mini-PCNL in supine position on the treatment of complex renal calculi: feasibility study

OBJETIVO: Mini-NLP es una técnica con menor potencial de invasividad que nefrolitotomía percutánea convencional (NLP). Se presenta una experiencia que compara los resultados de ambos abordajes en pacientes con litiasis complejas y/o de gran tamaño. MÉTODOS: Estudio prospectivo no aleatorizado, que compara resultados perioperatorios y postoperatorios de NLP a través de nefroscopio 24/26F (Grupo A) y Mini-NLP 15/18F (Grupo B) en 40 pacientes (20 cada grupo) consecutivos intervenidos entre 2013 y 2014. Se analizan datos demográficos, analíticos y microbiológicos, características de la litiasis renal, tiempo operatorio, sitio de punción, número de trayectos, tipo de fragmentación, colocación de nefrostomía, estancia hospitalaria, tasa de aclaramiento litiásico, eficacia y complicaciones según clasificación Clavien-Dindo. RESULTADOS: La evolución ha sido creciente para Mini-NLP, realizándose con este abordaje los últimos 17 casos consecutivos. No se detectaron diferencias preoperatorias en lateralidad, edad, sexo o ASA; pero sí en IMC (mediana Grupo A: 26,35 kg/m2; mediana Grupo B: 33,05 kg/m2, p = 0,008). La mediana de superficie litiásica (SC=longitud X anchura X π X 0,25) fue mayor en mini-NLP (6,69 vs 14,14 cm2; p = 0,003). El tiempo operatorio fue mayor en mini-NLP (120 vs 162,5 min; p = 0,03). Solo se transfundió 1 caso (5%) en el grupo de NLP 24/26F. Mini-NLP se asoció a técnica tubeless (55%) (p = 0,022), lo que explica menor puntuación EAV de dolor a las 24h de la cirugía (p = 0,0004). La estancia hospitalaria fue equivalente (mediana: 2 días; p = 0,8). Ambas técnicas presentaron una eficacia (SFR a los 3 meses) del 80%. No existieron diferencias estadísticamente significativas entre el número y severidad de las complicaciones entre ambos grupos (Grupo A: 15%, 66,7% Clavien II; Grupo B: 15%; 66,7% Clavien II; p=1). CONCLUSIONES: Mini-NLP permite tratar litiasis renal de gran tamaño e incluso litiasis coraliformes, sin necesidad de nefrostomía en un porcentaje alto de pacientes. La evolución técnica hacia un abordaje de calibre reducido mantiene la eficacia del procedimiento sin impactar la seguridad del mismo y con ventajas percibidas por los pacientes como es menor dolor postoperatorio

OBJECTIVE: Mini-PCNL is a potentially less invasive technique than standard percutaneous nephrolithotomy (PCNL). We present our experience and results comparing both approaches in large burden complex renal calculi. METHODS: Prospective non randomized study comparing PCNL (24/26F nephroscope; Group A) and Mini-PCNL (15/18F; Group B) perioperative and postoperative results, in 40 (20 each group) consecutive patients between 2013 and 2014. We analyze demographic data, hemoglobin drop, urine culture, stone characteristics, operative time, puncture, number and size of the tract, disintegration energy sources, nephrostomy placement, hospital stay, stone free rate and Clavien-Dindo complications.RESULTS: Evolution has shown growth for Mini-PNL, with the last 17 consecutive cases performed by this approach. No preoperative differences in laterality, age, gender or ASA were found; but there were differences in BMI (median Group A: 26.35 kg/m2; Median Group B: 33.05 kg/m2, p = 0.008). Median calculi surface area (SA = length X width X π X 0.25) was higher for mini-PNL (6.69 cm2 vs 14.14; p = 0.003). The operative time was longer for mini-PNL (120 vs 162.5 min, p = 0.03). Only one case (5%) required transfusion in NLP 24/26F. Mini-PCNL was associated with tubeless technique (55%) (p = 0.022), which explains lower 24 h postoperative pain, after surgery, measured by VAS (p = 0.0004). The hospital stay was equivalent (median: 2 days; p = 0.8). Both techniques showed efficacy (SFR at 3 months 80%). There were no statistically significant differences between the number and severity of complications between groups (Group A: 15%, 66.7% Clavien II, Group B: 15%; 66.7%. Clavien II, p = 1). CONCLUSIONS: Mini-NLP can manage kidney stones and even large staghorn calculi without nephrostomy in a high percentage of patients. The technical evolution towards a small caliber approach maintains the effectiveness of the procedure without impacting its safety, with benefits perceived by patients such as less postoperative pain