[Kidney transplant urinary complications. Diagnosis and treatment.] / Complicaciones urinarias del trasplante renal. Diagnóstico y tratamiento.

There are different surgical techniques for reconstruction of the urinary tract in kidney transplant. However, urinary complications are frequent in the postoperative period, being the ureter the frequent location of these complications. This results in high health care costs, increasing patient morbimortality and sometimes graft loss. For this reason, prevention, correct diagnosis and treatment are important. The aim of this review is to describe the surgical techniques most commonly used in kidney transplant for ureteroneocystostomy. To analyze the advantages and disadvantages of each of them and to compare their complications. On the other hand, we summarize the recent literature on the four most frequent urinary complications in the postoperative period after transplantation. The possible causes and treatment of urine leak, ureteri cobstruction, hematuria and vesicoureteral reflux are presented.

Existen diferentes técnicas quirúrgicas para la reconstrucción del tracto urinario en el trasplante renal. Sin embargo es frecuente la aparición de complicaciones urinarias en el postoperatorio, siendo el uréterla localización frecuente de las mismas. Esto implica un alto gasto sanitario, aumentando la morbimortalidad del paciente y pudiendo llegar a desencadenar la pérdida del injerto. Por ello es importante la prevención, el correcto diagnóstico y su tratamiento. El objetivo de esta revisión es describir las técnicas quirúrgicas más usadas en el trasplante renal para la ureteroneocistostomía. Analizar las ventajas y desventajas de cada una de ellas y comparar sus complicaciones. Por otro lado se resume la literatura reciente sobre las cuatro complicaciones urinarias más frecuentes en el postoperatorio del trasplante. Se exponen las posibles causas y tratamiento de la fuga urinaria, la obstrucción ureteral, la hematuria y el reflujo ureterovesical.

Laparoscopic donor nephrectomy versus open donor nephrectomy: Outcomes from a single transplant center. / Nefrectomía laparoscópica del donante vivo en comparación con nefrectomía abierta del donante vivo.

OBJECTIVES: Laparoscopic donor nephrectomy (LDN) is currently replacing open donor nephrectomy (ODN) across the world. Its advantages in terms of patient recovery are well known. We sought to compare surgical outcomes, particularly renal function during the post-nephrectomy period, for renal grafts procured by LDN versus ODN in our center. METHODS: We retrospectively analyzed all cases of living donor nephrectomies performed from 2004 to 2014 at Hospital Universitario La Paz. We compared demographic data; medical background, operative times, post-operative complications, and renal function follow up at 6, 12 and 18-month controls. RESULTS: A total of 114 living donor nephrectomies were performed: 85 LDN and 29 ODN. Demographic characteristics and medical background were similar among both groups, except mean donor age; 41.4 vs 47.4 years (p = 0.009) in the LDN and ODN groups respectively. LDN was used predominantly for left kidneys (83 out of 85), and ODN for right kidneys (28 out of 29). Although not significantly, mean operative time was shorter for the LDN group (169.37 vs 181.46 minutes; p = 0.2). Mean warm ischemia time was shorter for the ODN group (2.92 vs 2.36 minutes; p = 0.28). Differences between post-operative complications were not statistically different between both groups (p = 0.19). There were no conversions from LDN to ODN, and no re-admissions were registered. Length of stay was slightly shorter in LDN but not different (4.29 vs 4.92 days; p = 0.43). Renal function follow-up, measured with serum creatinine levels showed no difference over time (p = 0.67). CONCLUSIONS: Data from our series demonstrate that outcomes and renal function follow up over time were similar among both groups. In expert hands, this altruistic procedure can be performed with a minimally invasive approach without an increased complication rate or compromising renal function in donors.

OBJETIVOS: La nefrectomía laparoscópica del donante vivo (NLDV) está reemplazando actualmente a la nefrectomía abierta (NADV) en todo el mundo. Sus ventajas en términos de recuperación del paciente son bien conocidas. Comparamos los resultados quirúrgicos, particularmente función renal durante el periodo postnefrectomía, para los injertos obtenidos en nuestro centro por NLDV o NADV. MÉTODOS: Analizamos retrospectivamente todos los casos de nefrectomía del donante vivo realizados entre 2004 y 2014 en el Hospital Universitario La Paz. Comparamos los datos demográficos, antecedentes médicos, tiempo operatorio, complicaciones postoperatorias y funcion renal a los 6, 12 y 18 meses de seguimiento. RESULTADOS: Se han realizado un total de 114 nefrectomías del donante vivo: 85 NLDV y 29 NADV. Las características demográficas y antecedentes médicos eran similares entre ambos grupos, excepto la edad media del donante: 41,4 vs 47,4 años (p = 0,009) en los grupos de NLDV y NADV, respectivamente. La NLDV se utilizó preferentemente para riñones izquierdos (83 de 85) y la NADV para los riñones derechos (28 de 29). Aunque no fue significativo, el tiempo medio de operación del grupo de NLDV fue menor que el de NADV (169,37 vs 181,46 minutos; p = 0,2). El tiempo medio de isquemia caliente era menor en el grupo de NADV (2,92 vs 2,36 minutos; p = 0,28). No hubo diferencias estadísticamente significativas en las complicaciones postoperatorias entre ambos grupos (p=0,19). No hubo conversión a cirugía abierta en ninguna NLDV y no se registró ningún reingreso. La estancia hospitalaria fue ligeramente menor en la NLDV pero la diferencia no fue estadísticamente significativa (4,29 vs 4,92 días; p = 0,43). La función renal en el seguimiento, medida con los niveles de creatinina sérica no mostró diferencias con el tiempo (p = 0,67). CONCLUSIONES: Los datos de nuestra serie demuestran que los resultados y función renal en el seguimiento eran similares entre ambos grupos. En manos expertas, este procedimiento altruista puede ser realizado con un abordaje mínimamente invasivo sin aumento de la tasa de complicaciones o compromiso de la función renal del donante.

Human native Cav1 channels in chromaffin cells: contribution to exocytosis and firing of spontaneous action potentials.

The present study was performed to evaluate the Cav1 channel subtypes expressed in human chromaffin cells and the role that these channels play in exocytosis and cell excitability. Here we show that human chromaffin cells obtained from organ donors express Cav1.2 and Cav1.3 subtypes using molecular and pharmacological techniques. Immunocytochemical data demonstrated the presence of Cav1.2 and Cav1.3 subtypes, but not Cav1.1 or Cav1.4. Electrophysiological experiments were conducted to investigate the contribution of Cav1 channels to the exocytotic process and cell excitability. Cav1 channels contribute to the exocytosis of secretory vesicles, evidenced by the block of 3µM nifedipine (36.5±2%) of membrane capacitance increment elicited by 200ms depolarizing pulses. These channels show a minor contribution to the initiation of spontaneous action potential firing, as shown by the 2.5 pA of current at the threshold potential (-34mV), which elicits 10.4mV of potential increment. In addition, we found that only 8% of human chromaffin cells exhibit spontaneous action potentials. These data offer novel information regarding human chromaffin cells and the role of human native Cav1 channels in exocytosis and cell excitability.

Therapeutic concentrations of varenicline in the presence of nicotine increase action potential firing in human adrenal chromaffin cells.

Varenicline is a nicotinic acetylcholine receptor (nAChR) agonist used to treat nicotine addiction, but a live debate persists concerning its mechanism of action in reducing nicotine consumption. Although initially reported as α4ß2 selective, varenicline was subsequently shown to activate other nAChR subtypes implicated in nicotine addiction including α3ß4. However, it remains unclear whether activation of α3ß4 nAChRs by therapeutically relevant concentrations of varenicline is sufficient to affect the behavior of cells that express this subtype. We used patch-clamp electrophysiology to assess the effects of varenicline on native α3ß4* nAChRs (asterisk denotes the possible presence of other subunits) expressed in human adrenal chromaffin cells and compared its effects to those of nicotine. Varenicline and nicotine activated α3ß4* nAChRs with EC50 values of 1.8 (1.2-2.7) µM and 19.4 (11.1-33.9) µM, respectively. Stimulation of adrenal chromaffin cells with 10 ms pulses of 300 µM acetylcholine (ACh) in current-clamp mode evoked sodium channel-dependent action potentials (APs). Under these conditions, perfusion of 50 or 100 nM varenicline showed very little effect on AP firing compared to control conditions (ACh stimulation alone), but at higher concentrations (250 nM) varenicline increased the number of APs fired up to 436 ± 150%. These results demonstrate that therapeutic concentrations of varenicline are unlikely to alter AP firing in chromaffin cells. In contrast, nicotine showed no effect on AP firing at any of the concentrations tested (50, 100, 250, and 500 nM). However, perfusion of 50 nM nicotine simultaneously with 100 nM varenicline increased AP firing by 290 ± 104% indicating that exposure to varenicline and nicotine concurrently may alter cellular behavior such as excitability and neurotransmitter release.

[Renal autotransplantation: a valid option in the resolution of complex cases]. / Autotrasplante renal: una alternativa valida en la resolucion de casos complejos.

OBJECTIVES: To analyze the current indications for renal autotransplantation, as well as the technical features, complications and long-term follow-up of the technique. METHODS: From 1990 to 2005 we have performed autotransplantation in 10 patients, 7 adults and 3 children. The indication was established due to vascular pedicle pathology in 8 cases and ureteral lesion in 2. The cause of vascular pathology was: atherosclerotic stenosis (4), dysplastic stenosis (2), Takayasu's disease stenosis (1), and renal artery aneurysm (1). The patients with ureteral lesion had ureteral stenosis secondary to Crohn's disease in one case, initially solved by ureteral stent and subsequently obstructed by lithiasic encrustation, and ureteral avulsion in the other case. The vascular grafts employed in the 8 cases with vascular reconstruction were: hypogastric artery 7 cases, and sophena vein in one case. Ureteral reimplantation was necessary in 5 cases after bench surgery; in other five cases vascular reconstruction was performed without ureteral division. All grafts were perfused with 4 degrees C lactate ringer or Wisconsin solution and protected with surface cold ischemia. Ischemia times ranged from 42 to 89 minutes. RESULTS: Nine kidneys (90%) functioned after autotransplantation, 8 of them had immediate function, and one had delayed graft function after a six-day period of acute tubular necrosis. The kidney with arterial stenosis secondary to Takayasu's disease never functioned. The cause of graft loss was renal vein thrombosis. Postoperative mortality was zero. After a mean follow-up of 72+/- 13 months mean serum creatinine is 1.6+- 0.4 mg/dl (1.1-2.4) and 70% (7/10) of the patients have normal blood pressure without antihypertensive medication. CONCLUSIONS: Currently, renal autotransplantation, with or without extracorporeal vascular reconstruction, is a complex technique with exceptional indications, but it allows recovering renal units with vascular pathology not amenable to angioplasty or in situ revascularization. It is also a valid alternative to ileal ureteral substitution in cases of extensive ureteral lesion.

[Immunosuppression and surgical complications after renal transplantation]. / Inmunosupresión y complicaciones quirúrgicas post-trasplante renal.

OBJECTIVES: The new immunosuppressive regimens in kidney transplantation have diminished the rate of acute rejection and improved graft survival. However, the use of new agents results in the development of surgical complications. The authors analyze the incidence of such complications accordingly to the type of drug. METHODS: This study included 350 kidney transplantations performed between January 1997 and December 2004. The average age was 54 years. The incidence of diabetes mellitus was 8.5% and the rate of obese recipients (BMI >30 kg/m2) was 15.4%. The average follow-up rate was 44 +/- 5.6 months (5-96). A surgical complication was defined as any complication directly related to the surgical transplant that occurs along the first year after transplantation. RESULTS: The incidence of surgical complications was 34.8% (122/350). The rates of perigraft collections and bleeding posttransplant were significantly higher in the CsA group than in the Tacro one: 12% vs. 3.8% (p = 0.005) and 11.5% vs. 3% (p = 0.002). The Sirolimus and Everolimus-based immunosuppresive regimens led to a higher incidence of lymphocele (16% vs. 3.7%) (p = 0.012). There were no significant difference in the incidence of surgical complications in recipients immunosuppressed with and without MMF, and in diabetic vs. no diabetic patients. Surgical complications were higher in obese patients (66.5% vs. 33.5%) (p = 0.002). CONCLUSIONS: Recipients receiving Sirolimus/Everolimus demonstrated a significantly higher lymphocele rate. The CsA regimens were associated with bleeding and post transplant pararenal fluid collections. The introduction of MMF did not result in a significant increase in posttransplant surgical complications. The obesity was a risk factor associated with those complications.

[Ultrasound for the diagnosis of female urinary incontinence]. / Ecografía en el diagnóstico de la incontinencia urinaria femenina.

OBJECTIVES: The value of ultrasonography for the study of female urinary incontinence has been redefined over the last years. METHODS: We review the literature about the value of ultrasound in the workup of females with urinary incontinence, mainly transperineal ultrasound for the female stress urinary incontinence (SUI). RESULTS: Many papers have been published over the last few years. Upper urinary tract ultrasound has not a place in the workup of genuine female SUI. Transperineal ultrasound allows to evaluate the mobility of the bladder neck and urethra, the thickness of the bladder wall, the funnel shape of the bladder neck, the presence of SUI or pelvic organ prolapse (POP), to visualize mesh implants, to help with biofeedback, and to evaluate changes after surgical treatment. CONCLUSIONS: Ultrasounds in general, and transperineal or translabial ultrasound in particular, are in the process of becoming the standard diagnostic method in urogynecology. Their wide availability, the standardization of parameters, the possibility of evaluating not only the bladder but also the levator ani muscle or pelvic organ prolapses (POP) contribute to this fact. It allows to obtain data in a non invasive way before and after therapy.