Posterior laparoscopic tuberculous nephrectomy is currently one of the difficulties in laparoscopic surgery in urology, the internal structure of the tuberculous kidney is obviously destroyed, filled with caseous necrotic pus, and adhered to the peripheral tissues of the kidney, which makes it more difficult to free it under the laparoscope. It is reported as follows. I. Clinical data and methods 1. General data There were 46 cases in this group, 19 male and 27 female. The age of 46 cases, 19 male and 27 female, ranged from 20 to 64 years old, with a median age of 34 years old. Preoperative routine investigation of blood antibody to Mycobacterium tuberculosis, blood sedimentation, urine smear of Mycobacterium avium, IVU and CT, diagnosed as unilateral renal tuberculosis, with or without ureteral tuberculosis, loss of renal function or severe impairment of the affected side, the contralateral side of the kidney is basically normal, there is no active extrarenal tuberculosis foci, and the regular anti-tuberculosis treatment was carried out before the operation: triple or quadruple medication: rifampicin 0.45 g orally, once/day (or rifapentine), 0.45 to 0.6 g of rifapentine, 0.45 to 0.6 g of rifapentine. Rifampicin 0.45-0.6 g orally 2 times/week, Isoniazid 0.3 g orally 1 time/day, Ethambutol 0.75 g orally 1 time/day, Pyrazinamide 0.5 g orally 3 times/day. At least two weeks of preoperative medication. 2.Methods （1）After successful general anesthesia, take the healthy side lying position, with the lumbar bridge padded. All used STORZ HD 30° high-definition laparoscope, lumbar take 3 trocar puncture access (10 mm 1, 12 mm 1 5 mm 1). The first puncture point was selected in the posterior axillary line under the 12-rib margin with a transverse incision of 1.5-2.0 cm. Vascular forceps bluntly detached the lumbar dorsal fascia, which was separated with a fingertip or a middle curved forceps, and entry into the retroperitoneal space was demonstrated by the insertion of a finger with a sense of space or flaccidity, and by the upward palpation of the smooth medial surface of the 12 ribs. With the index finger in the retroperitoneal fat separation of a gap, into the homemade balloon expander, injection of gas 350 ~ 400mL, 3 ~ 5 min after the removal of the balloon, inserted into the 12mm trocar, trocar needle and the gap between the skin to be stitched up a needle to prevent gas leakage in the pneumoperitoneum. The second and third puncture points were made under finger guidance. The second puncture point is selected at the intersection of the anterior axillary line and the subcostal margin or 8-10 cm forward of the first puncture point under the costal margin, using a 5 mm trocar. the third puncture point is located in the mid-axillary line at the upper margin of the iliac spine, using a 10 mm trocar. the pneumoperitoneum is connected to the pneumoperitoneum machine, CO2 is injected, and the air pressure is maintained at 12-14 cm Hg. (2) Freeing the kidneys and the ureter after clearing the extra-peritoneal fat, and then cut the lateral conus fascia below the retroperitoneal reflex line to prevent gas leakage in the pneumoperitoneum. After clearing the extraperitoneal fat, the lateral cone fascia and perinephric fascia were incised below the fold line, and firstly, a gap was separated in the relatively avascular area between the perinephric fat capsule and the perinephric fascia on the ventral side of the kidneys, and no extensive freeing was done to prevent the kidneys from prolapsing and affecting the subsequent operation. The renal artery is then carefully freed at the dorsal renal hilum outside the perirenal fat capsule in front of the psoas major muscle, where it is usually heavily adherent due to inflammation and most of the enlarged lymph nodes, requiring patience and careful, sharp ultrasonic knife freeing to prevent severe blood seepage to interfere with the operation.The renal artery is dissociated after blocking by Hem-o-lok clamping. The renal artery was searched for and freed from the renal vein below the inner renal artery, which was also cut off by Hem-o-lok clamp. In three cases, the renal vein could not be dissected out because of severe adhesions at the renal hilum, and the renal vein and surrounding tissues were finally dissected using the Johnson & Johnson Endocutter linear cutter after the kidney was completely free. After the arteriovenous dissection, the renal vein was first dissected along the gap that had been created in the ventral part of the kidney, and then continued down to the lower pole of the kidney to find the ureter, which was dissected by clamping the Hem-o-lok. In severe cases of ureteral tuberculosis, the ureter was thickened and widened so that it could not be clamped and then dissected with a 10-gauge wire ligature. Then continue upward in the plane between the ventral fat capsule and the perirenal fascia, and converge with the dorsal plane of the kidney at the upper pole of the kidney, where the adhesions are usually more serious, and use the ultrasonic knife to sharply free between the perirenal fat and the upper pole of the kidney at a slow speed, being careful to leave the adrenal glands in the body to avoid injury. Sharp separation is the mainstay of renal freeing, especially in the renal pus accumulation is obvious, cortical thinning to avoid instrument extrusion, in order to prevent rupture of the pus cavity contamination of the operating field. After the kidney is completely free, put it into the specimen bag and take it out. (3) Removal of the specimen Put the cut kidney into the homemade kidney bag, tighten the line of the kidney bag, pull out the line from the first puncture point, and then make an incision of 5-7 cm from the first puncture point, and then take out the kidney from this incision. After checking that there was no bleeding on the wound surface, 1.0 g of streptomycin sulfate powder was spread in the operation field, and the incision was closed layer by layer without leaving a drain. II.RESULTS Except for 2 cases in the early stage, which were opened due to poor visualization of blood seepage at the renal hilum, all 44 cases successfully completed fat extracapsular nephrectomy. The operation time was 118 (80-186) min. intraoperative blood loss was 45.4 (10-350) ml. postoperative hospitalization time was 6.5 (5-8) days. There was no peritoneal injury or rupture of the abscess kidney, no perioperative complications, and the incisions all healed in one stage.46 cases were followed up for 1 to 43 months, with an average of 19 months, and the contralateral kidney function was normal. The gross specimen after resection showed that the kidney was filled with a large amount of caseous necrotic pus, and multiple foci of caseous necrosis were seen in the renal parenchyma, which were pathologically confirmed to be renal tuberculosis. After surgery, the patients were routinely given anti-tuberculosis drugs for six months to one year, and the liver function was regularly reviewed. III.DISCUSSION The incidence of renal tuberculosis has been rising significantly in recent years. Due to the extremely low early diagnosis rate, most of the tuberculosis has already developed into multiple pus cavity formation in the renal cortex, involvement of the collecting system, or concomitant tuberculous lesions in the ureter, which then accumulates in the bladder at the time of clinical diagnosis. Posterior laparoscopic nephrectomy for tuberculosis renal cases is basically the same as that of open surgery, and all patients need to undergo routine preoperative examinations such as IVU, nephrography and upper abdominal CT, in order to understand the lesions of the affected kidney and the function of the contralateral kidney, and to clarify the indications for surgery. For patients with severe renal destruction or loss of renal function, or complication of ureteral tuberculosis, resection of tuberculosis kidney is needed. Due to the long course of tuberculosis kidney, often accompanied by severe perinephric inflammation, perinephric fat and renal hilum have extensive adhesion, the affected kidney has more pus, high pressure, thin cortex, when laparoscopic freeing, especially the use of blunt detachment, it is easy to cause renal peritoneal tear, resulting in pus extravasation. Moreover, extensive adhesions at the perirenal and renal hilum, disorganization of normal anatomical structure, difficulty in laparoscopic separation, more bleeding, and higher rate of surgical conversion to open, were once considered as relative contraindications to laparoscopic surgery. With the advancement of laparoscopic technology and the improvement of surgeons’ surgical experience and skills, more and more reports have pointed out that posterior laparoscopic tuberculosis nephrectomy may now become the preferred method of resecting nonfunctional tuberculosis kidneys because it has the advantages of less trauma, less bleeding, and quicker recovery of the patient compared with open surgery. Laparoscopic nephrectomy can be performed by a variety of routes, such as perinephric fasciotomy similar to radical treatment of renal cancer, perinephric fasciotomy outside the perinephric fat capsule with preservation of the perinephric fascia, simple nephrectomy with incision of the renal fat capsule free on the surface of the kidney, as well as subperitoneal nephrectomy, as reported by Zhang Xu [1] and others. Perinephric tuberculosis is characterized by more severe inflammation the closer to the surface of the kidney and less severe inflammation away from the kidney. However, it is difficult to separate the perirenal fascia from the peritoneum due to the inflammatory stimulus, and forced separation carries the risk of peritoneal rupture and contamination of the peritoneal cavity, so separation at this level is not recommended. Foreign scholars have also reported on the immediate extraperitoneal detachment of the renal peritoneum. The author found that it is relatively easy to choose to separate in the relatively avascular gap between the perirenal fat capsule and the perirenal fascia, although there are adhesions, but it is not difficult, in case of serious adhesions, the ultrasonic knife can be used to cut immediately adjacent to the perirenal fat capsule surface can be effective to maintain the surgery in this gap. When separating, we should be patient, careful dissection, generally can free the complete kidney and the encapsulated fat capsule. Moreover, the abdominal surface is thickened perirenal fascia and peritoneum stimulated by long-term inflammation, which is generally not easy to penetrate, and this level is convenient to do a slightly blunt dissociation to reduce the risk of intra-abdominal intestinal and other collateral injuries. Moreover, there is still a certain distance between this gap and the kidney, so it is not easy to damage the renal parenchyma during the operation, and to avoid contamination of the surgical area by the overflow of renal caseous material. Moreover, after entering the perinephric fascia, a “tunnel” is first separated at this level without extensive dissection, and then the dissection area is further expanded at this level after dissecting the renal vessels. If the vessels are treated and then isolated at this level, it is not easy to isolate them because of the pneumoperitoneum pressure. The separation and treatment of the blood vessels at the renal hilum is the difficult and critical point of TB nephrectomy. In addition to conventional methods, careful preoperative radiographic comparison of the position of the renal artery with the enlarged lymph nodes at the renal hilum can help to find the renal artery quickly. In addition, because of the long-term inflammation stimulation of the renal hilum, the tissue is more brittle and easy to bleed, it is generally not suitable to do too much blunt separation here, and the ultrasonic knife is usually used to do sharp free. For lymph node obstruction affecting the separation, if necessary, ultrasonic knife transection of lymph nodes, or in its proximal (renal artery trunk) or distal (renal artery into the renal branch) carefully separated to find. Despite the difficulties, the renal arteries were successfully isolated in all cases in our group, except for two early cases of severe oozing blood in which the isolation failed to be neutralized and opened. Because the renal vein is deeper and more obviously affected by inflammatory stimulation, its separation is more difficult than that of the artery, and in three cases, the renal vein and the surrounding tissue were cut off with a linear cutter after the kidney had been completely freed. The author suggests that, for the sake of surgical safety and to prevent tearing and bleeding of the renal vein during the separation process, the linear cutter, although more expensive, is an ideal choice in some cases. Maintaining the integrity of the specimen intraoperatively is important for the prevention of tuberculosis mycobacterial dissemination and incision healing. In addition to separating the specimen under the perinephric fascia as far away from the renal surface as possible to prevent inadvertent injury to the kidneys and titanium clips on the end of the ureter, the specimen should also be removed with care, and the extension of the incision should be of an appropriate size, and the aseptic principle should not be neglected for the sake of pursuing the “minimally invasive” procedure, and it is recommended that the specimen be placed in a specimen bag and then taken out together. This procedure utilizes the gap between the perirenal fat and the perirenal fascia to avoid perirenal adhesions, which saves surgical time and is less likely to accidentally injure the kidneys and the peritoneum. The data in this group suggest that this procedure has less bleeding, does not easily damage the surrounding organs, is especially suitable for inflammatory kidneys with severe adhesions, and can ideally free the TB kidneys with severe adhesions, which further broadens the indications for laparoscopic treatment of renal tuberculosis. We believe that posterior laparoscopic tuberculosis nephrectomy is an ideal surgical treatment for tuberculosis nephrectomy because it is less traumatizing and quicker recovery than open surgery, and does not cause more surgical complications.