With the continuous development of imaging technology, more and more renal cysts have been found in the population [3, 4]. Renal cysts are very common in urology. Most patients with renal cysts are asymptomatic. Only a few patients have symptoms such as pain, hypertension, hematuria, recurrent urinary tract infection, and cyst rupture [5, 6]. According to Bosniak classification, the renal cysts are classified as simple cysts (Bosniak grade I and II) or complex cysts (Bosniak grade III and grade IV). At present, most scholars at home and abroad believe that for patients with simple renal cyst (Bosniak grade I and grade II), if the maximum diameter of cyst is less than 4 cm and there are no obvious clinical symptoms, the patient should be followed up regularly for reexamination. If the maximum diameter of the renal cyst is more than 4 cm and there is obvious renal parenchymal damage on imaging, or there are clinical symptoms of and hematuria, the patient should be treated actively. The aim is to prevent further progression of the disease and further damage to kidney function. At present, there are many treatment methods, such as ultrasound-guided puncture drainage + hardener injection , traditional open decortication renal cyst surgery, laparoscopic decortication renal cyst surgery, flexible ureteroscopic management of renal cyst [8, 9] and percutaneous decortication renal cyst surgery . Laparoscopic renal cyst decortication with less trauma, faster recovery and better efficacy is the preferred method for the treatment of simple renal cyst, especially for the younger patients with large cysts .A comparative study between the retroperitoneal approach and the peritoneal approach showed that the retroperitoneal approach had significantly shorter operative time than the retroperitoneal approach, which reduced the interference to the intestinal tract and significantly shortened the recovery time of intestinal function . In the case of cyst co-infection, the chance of peritoneal dissemination could also be reduced [13, 14].The disadvantages are that the operation space is small, the bilateral renal cyst cannot be treated at the same time, the peritoneum is easy to be injured and the operation technique requirements are high.
To make full use of limited bed resources and to provide more patients with efficient medical services, the national health administration department of China is continuously promoting day surgery through relevant quantitative indicators. The investigation found that general surgery, gynecology, orthopedics, urology and vascular surgery in our hospital have been performing day surgery. There have been many kinds of urological surgery performed in the day ward mode, including lithotripsy (soft) mirror ureter, bladder calculi lithotripsy, urethra stone lithotripsy, urethra meat with resection, occult penis orthopedics, cryptorchidism by fixation, stress urinary incontinence, etc. An analysis of risk factors for catheter-related urinary tract infections found that each additional day of catheter retention increased the risk of urinary tract infections .Since the hospital stay in the day ward mode does not exceed 24 hours, reducing the indwelling time of urinary catheters can further increase the turnover rate of patients when they are admitted to the hospital, and also greatly reduce the incidence of nosocomial infections. If postoperative infection occurs, in order to better select the appropriate antibiotic application, it is recommended that clinicians collect secretions and send them to bacterial culture as much as possible. Selection of appropriate patients, adequate preoperative assessment and related preparation are still important prerequisites for the success of daytime surgery [16, 17]. The results of this study showed that there was no significant difference between the inpatient group and the day group in terms of surgical effect (operation time, intraoperative blood loss, 10 months of postoperative follow-up for renal cyst recurrence), postoperative complication rate, postoperative quality of life score, and postoperative satisfaction rate. However, the total hospitalization time of patients in the day ward group is shortened to within 24 hours, and the time of postoperative drainage tube indwelling is also significantly shortened, which effectively reduces the medical expenses and saves health resources. But obviously, this study was a single-center study with a small sample size and all cases were cases of unilateral renal cyst. Therefore, bilateral renal cyst surgery could not be performed at the same time. Thus not all patients with surgically-indicated renal cysts could benefit in the day ward mode. We believe that in the future, with the development of medical technology and the accumulation of clinical practice, the indications for the inclusion of renal cysts in ambulatory surgery may be further broadened. With the development of the concept of accelerated rehabilitation surgery and postoperative pain-free surgery, the ambulatory surgery model has been widely carried out in the clinic with its simplified and standard diagnosis and treatment procedures, and has become an effective means to relieve the shortage of medical resource [18, 19].
This was a retrospective, single-center, case-control clinical study. Based on the literature and the results of this study, we summarized the characteristics and requirements of laparoscopic decortication for unilateral simple renal cyst in the day ward model in the following aspects: ① The outpatient doctor needed to strictly master the surgical indications of simple renal cyst. ② The patient with preoperative ASA assessment was I or Ⅱ. There were no obvious contraindications of operation and anesthesia. ③ The location, size and number of renal cysts as well as the relationship between renal cysts and peripheral vessels and renal collecting system were determined by preoperative b-ultrasound and CT examination. Meanwhile, Bosniak grade was conducted according to CT. ④ The distance between puncture points in retroperitoneal surgery should be moderate to avoid affecting the operation of intraoperative instruments and extending the operation time. ⑤ Without water capsule dilation, the position of the kidney did not change much. The surgeon should carefully dissect the layers of tissue surrounding the kidney. When the renal fascia was opened near the psoas major, the avascular area of the renal fascia was clearly visible. Along this vascularized area, the renal fascia fully dissociated the dorsal kidney and revealed the renal contour. At the same time, combined with preoperative imaging, the surgeon determined the location of intraoperative renal cyst. A few renal fat sacs were incised at the site of the cyst and to reveal a blue-purple cyst. Then the capsule fluid was sucked away and the capsule wall was removed [20, 21]. ⑥ The competent doctors and nurses timely assessed the degree of postoperative pain, the recovery degree of intestinal function and the number of postoperative drainage, helping the patients successfully complete the 24-hour admission.
In summary, we recommended that retroperitoneal laparoscopic unilateral simple renal cyst decortication was safe and feasible in the day ward model for patients who were eligible for the conditions of inclusion criteria. It helped to reduce the consumption of medical resources, reduce nosocomial infections and reduce intravenous fluids. Day surgery is considered to be a high-quality, safe and cost-effective surgical method, which requires clinicians continuously explore and accumulate evidence of evidence based medicine through more clinical practice, to improve medical safety and quality and reduce medical costs, so as to benefit more patients. In addition, for the current prevention and control of the spread of COVID-19, day surgery is also a good choice for patients.