The reporting of this study conforms to CARE guidelines. In Dec. 3, 2021, a 64-year-old man with a solid space-occupying lesion that measured 25 x 36 mm in the inferior pole of the left kidney by Doppler ultrasound during physical examination one month prior. The body mass index (BMI) was 22.19 kg/m2. Meanwhile, the patient was generally well, was afebrile, and did not experience low back pain or discomfort, frequent urination, urgency, painful urination and gross haematuria. Additionally, the patient denied gastrointestinal symptoms such as abdominal pain and distention, nausea and vomiting. The patient had a 6-year special history of hypertension, and his blood pressure was well controlled by regular oral antihypertensive drugs. During hospitalisation, his maximum monitored blood pressure (BP) was 135/97 mmHg, and his monitored heart rate ranged from 72 to 90 bpm. The patient denied any history of other medications, diabetes, abdominal surgery or trauma, abdominal tuberculosis, peritoneal dialysis, autoimmune disease, or chemotherapy. Preoperative blood tests and comprehensive metabolic panel suggested no abnormalities. Renal Doppler ultrasound showed a solid space-occupying lesion in the left kidney, which required further evaluation. Computer tomography urography (CTU) and angiography (CTA) showed that the stomach and spleen were located in the right abdominal cavity, while the right hepatic lobe, gallbladder and inferior vena cava were at the left side of his abdomen (Figures 1A-E), the bilateral kidneys were normal in size and shape, but a 24 x 35 mm isodense mass protruded from the outline of the left kidney (Figures 1B-E). On contrast-enhanced computed tomography (CT) scan, the mass was strongly enhanced in the arterial phase (Figure 1C), and the enhancement pattern was attenuated during the venous phase (Figure 1D). There was a 31 x 40 mm non-enhancing hypodense nodule and calcification of the wall in the right renal. Additionally, the left renal artery was supplied by one renal artery and one accessory renal artery (Figure 1E). Effusion or lymphadenopathy in the abdominopelvic cavity was not noted. Based on the above findings, the patient was confirmed as having SIT, for the space-occupying lesion in the left kidney, clear cell RCC (ccRCC) was considered, the lesion in the right kidney was probably cystic. Cardiac Doppler ultrasound demonstrated decreased diastolic function and normal systolic function of the left ventricle in the transposed heart. The estimated glomerular filtration rates (eGFR) were 29.76 and 28.8 ml/min for the left and right kidneys, respectively. Chest CT showed no space-occupying lesions or evident abnormalities. Before surgery, the patient was diagnosed with left RCC, SIT, right renal cyst and hypertension. We diagnosed our patient as having a cT1aN0M0 left RCC, and the RENAL score was 7x. With PN being the preferred treatment approach, left RALPN was performed after obtaining informed consent.
Surgery was performed under general anaesthesia with the patient being placed in a supine position and angled at 70  on the unaffected side. A 1.0 cm incision was created at the medial umbilical edge for insertion of a Veress needle and induction of CO2 pneumoperitoneum that was maintained at 15 mmHg. A laparoscope was then inserted to observe the abdominal cavity, adhesions were observed between the entire colon and the anterior abdominal wall, particularly between the intestines (Figures 2A,B). Based on these findings, abdominal cocoon was diagnosed. Under direct laparoscopy, two 8-mm robotic ports were respectively placed in adhesion-free areas in the intestine 4 cm from the anterior superior iliac spine and under the costal margin (Figure 3A), while a 12-mm assistant port was inserted 5 cm under the umbilicus at the midline (Figure 3A). When the robotic laparoscopy system was ready, adhesions between the colon and the anterior abdominal wall were removed (Figure 2B-D). The transposed organs, including the liver, spleen, stomach and colon, were then noted (Figure 2C,D). The inferior vena cava was located on the left side (Figure 2E-H). A protruding tumour (Figure 2G) was found in the left kidney, three arterial branches were dissected (including one from the abdominal aorta to the lower pole of the kidney, and two from the main renal artery to the middle and lower poles of the kidney) (Figure 2F). The surgery was uneventful, and the tumour was resected successfully while preserving the tumour capsule (Figure 2I). The operation time was 180 min, which included 23 min of warm ischemia time. The intraoperative blood loss was 200 ml. A 23 x 36 mm specimen was removed from the left kidney and sectioned to confirm tumour capsule integrity (Figure 3B). Pathology revealed pT1aN0M0 Fuhrman Grade I ccRCC, which did not involve the surgical margins (Figure 4A,B). No intestinal injury or any other complication occurred in the intraoperative or postoperative. The patient was satisfied with the treatment. The patient was discharged at postoperative on day 7. Postoperatively, the patient was followed up for 10 months, and no recurrence, secondary infection, or intestinal obstruction was detected.