Congenital megacystis of the ureter

　　1. Etiology

　　1The etiology is currently without a unified view, and it may be due to hyperplasia of the ureteral muscle layer during embryonic development or an imbalance in the ratio between muscle bundles and collagen fibers. The lower end of the ureter is narrowed near the bladder, and there is a sharp contrast between the narrowed and dilated segments. In some cases, there are transverse mucosal folds or canvas-like flaps inside the lumen of the lower end of the ureter.

　　2A ureteral megacystis without动力 in the distal part has no anatomical narrowing, but it is dilated at the proximal end, without peristaltic function. Under the microscope, the muscular layer of the ureter is relatively lacking, there is hyperplasia of the circular muscle, and in some cases, a decrease in the number of intermuscular nerve cells can be seen.

　　Second, pathogenesis

　　The pathogenesis of congenital巨输尿ism has not been fully elucidated. According to the research of histopathology, most scholars believe that it may be related to the following points:

　　1、The longitudinal muscle in the wall of the terminal ureter is lacking.

　　2、Collagen fiber proliferation in the muscular layer at the end of the ureter causes a disorder in the ratio of muscle bundles to collagen fibers, and the arrangement of the muscular layer is disordered.

　　3、The muscular layer at the end of the ureter thickens, and there is inflammation of the mucosa or submucosa. Due to the combined action of one or several factors, the peristaltic function of this segment of the ureter is weakened or disappears, the urine excretion is not smooth, the pressure in the proximal ureter increases, leading to ureteral dilation and renal hydrops.

　　1、Urological infection (urinary tract infection, UTI) refers to the growth and reproduction of pathogens in the urinary tract, and the inflammation caused by invasion of the mucosa or tissue of the urinary tract. It is the most common type of bacterial infection. Urological infection is divided into upper urinary tract infection and lower urinary tract infection. Upper urinary tract infection refers to pyelonephritis, and lower urinary tract infection includes urethritis and cystitis. Pyelonephritis is further divided into acute pyelonephritis and chronic pyelonephritis, which are more common in women.

　　2、Calculi are solid masses formed in the lumen of the conduit cavity or hollow organs in the human or animal body (such as kidneys, ureters, gallbladder, or bladder, etc.).

　　Congenital巨输尿ism has no specific clinical manifestations, most of them present with lumbago and distension, and occasionally patients present with lumbar mass, hematuria, refractory urinary tract infection, and renal insufficiency.

　　Principles of medication

　　1、The use of antibiotics is a necessary means to ensure the success of surgery and reduce renal infection, which is also to protect renal function. Therefore, it is advisable to use antibiotics with low nephrotoxicity and perform them under the reference of drug sensitivity test and renal function indicators, so as to target effectively.

　　2、Try to use fresh blood for blood transfusion during surgery, especially in patients with renal insufficiency. Kidney protection therapy is also very important.

　　When accompanied by urinary tract infection and calculus, urine examination may show red blood cells, white blood cells, and pathogenic bacteria.

　　Cystoscopy examination of the trigone and ureteral orifice position is generally normal, especially in adults, and the insertion of the ureteral catheter can be done without difficulty. In early cases, the X-ray film only shows the lower segment of the ureter in a spindle-like or spherical expansion; immediately after the injection of contrast agent, the ureteral catheter is removed to take an emptying film, and the phenomenon of contrast agent retention and delayed emptying can be seen.

　　1、In X-ray films, the phenomenon of reflux of contrast agent in the ureter back to the kidney can be seen.

　　According to X-ray urography, changes in the shape of the renal calices and renal parenchyma can be observed, thus estimating the extent of damage.

　　2、Renal calices: The renal calices can change from normal, with a flat calice orifice, irregular orifice, bulging outward, up to the spherical expansion of the renal calices.

　　Renal parenchyma: The renal parenchyma can be normal in thickness (usually2cm above), the thickness is in1～2cm entre, até que a espessura fique mais fina (crianças em1cm abaixo, bebês em 0.5cm abaixo) sofrerem diferentes graus de lesão.

　　3、Ultrassonografia: pode ver a dilatação da ureter lateral, pode haver ou não hidronefrose significativa.

　　4、CT e MRI: o CT pode ver a dilatação completa da ureter, pode haver diferentes graus de hidronefrose, a junção ureterovesical pode ver estreitamento, o MRI pode ver a visão completa da ureter dilatada, a parte inferior é estreita, pode haver hidronefrose.

　　A dieta dos pacientes com ureter megacística congenita deve ser leve e fácil de digerir, comer mais vegetais e frutas, combinar a dieta de maneira razoável, prestar atenção à nutrição suficiente. Além disso, os pacientes devem evitar alimentos picantes, gordurosos e frios.

　　Primeiro, tratamento

　　O tratamento de grande ureter congênita em adultos depende da extensão da dilatação da ureter e da lesão renal.

　　1、Para pacientes com dilatação da ureter leve e hidronefrose não significativa, pode-se observar de perto. Existem relatos de que cerca de40% dos casos podem optar por tratamento conservador.

　　2、Se a dilatação da ureter for significativa e a lesão renal não for grave, pode-se realizar cirurgia de correção da ureter e reimplantação vesical. Durante a cirurgia, deve-se切除 a extremidade1～2cm da lesão da ureter. Durante a cirurgia, deve-se切除 parte da parede lateral externa inferior da ureter, com comprimento equivalente a1/3，mas não pode exceder1/2，a fim de evitar a isquemia e necrose. É necessário realizar a reimplantação da ureter vesical anti-reflux, podendo ser cortada a camada muscular e serosa na parede lateral superior da bexiga, com comprimento de3～4cm, cortando a mucosa no extremo distal para formar uma pequena abertura e anastomose com a mucosa da ureter, enterrando a porção inferior da ureter na camada muscular e sutureando a camada muscular e serosa.

　　3、Para pacientes com hidronefrose grave e lesão renal grave, deve-se realizar cirurgia de nefroureterectomia. Em caso de infecção, pode-se realizar drenagem de fístula renal antes de controlar a infecção e, em seguida, realizar nefroureterectomia.

　　Complicações pós-operatórias e prevenção: ① Necrose da ureter: clinicamente manifestada por fístula urinária e infecção de incisão. Durante a cirurgia, deve-se proteger a camada vascular da ureter externa, e o diâmetro da ureter sutureada não deve ser muito fino. Em caso de complicações mencionadas acima, pode-se realizar cirurgia de drenagem da área operatória, prolongar o tempo de remoção do cateter de suporte, e, se necessário, realizar fístula renal temporária para drenar o urino. ② Estreitamento da ureter: pode ser causado por cortes excessivos na ureter, diâmetro muito fino após a sutura ou infecção urinária recorrente causando hiperplasia fibrosa. Durante a cirurgia, deve-se prestar atenção à adequação do corte da ureter.