Comparison of lateral transperitoneal versus retroperitoneal laparoscopic adrenalectomy for pheochromocytoma: a single-centre retrospective study.

Laparoscopic adrenalectomy (LA) has became the standardized treatment for pheochromocytoma. The aim of this study was to evaluate outcomes of lateral transperitoneal and retroperitoneal LA for pheochromocytoma. Between January 2011 and December 2021, 142 patients with pheochromocytoma underwent LA via lateral transperitoneal (123 patients) or retroperitoneal (19 patients) approaches. Data of these patients were assessed to investigate the differences in perioperative outcomes and intraoperative haemodynamic parameters between the two procedures. Clinical parameters at presentation were comparable between the two groups, except for tumour size, which was larger in the transperitoneal group (50 [10-115] mm vs 35 [7-110] mm, P = 0.012). There were no significant differences between the two groups in terms of operation time, estimated blood loss, intraoperative transfusion rate, incidence of complications, conversion to open surgery, postoperative analgesic requirement, time to first oral intake, or mean hospital stay. Intraoperative haemodynamic parameters of the two groups were similar. After adjusting for tumour size using propensity score matching, both perioperative outcomes and haemodynamic parameters were still comparable. Lateral transperitoneal and retroperitoneal laparoscopic adrenalectomies provide similar perioperative and haemodynamic outcomes for surgical resection of pheochromocytoma.

Risk factors for hemodynamic instability during laparoscopic resection of pheochromocytoma.

BACKGROUND: Laparoscopic adrenalectomy for pheochromocytoma is associated with high risk of intraoperative hemodynamic instability. Our study aimed to identify predictive factors for hemodynamic instability during laparoscopic resection of pheochromocytoma. METHODS: Between January 2011 and December 2021, 136 patients underwent unilateral laparoscopic adrenalectomy for pheochromocytoma. The patients were divided into 2 groups depending on the presence or absence of hemodynamic instability during surgery. Intraoperative hemodynamic parameters were compared between the 2 groups. Patient demographic characteristics and preoperative evaluations were assessed for their prognostic relevance with respect to intraoperative hemodynamic instability via both univariate analysis and multivariate logistic regression analysis. RESULTS: There was greater blood pressure fluctuations and higher maximum blood pressure and heart rate in the hemodynamic instability group. More patients need intraoperative administration of vasoactive drugs in the hemodynamic instability group. In the univariate analysis, presence of coronary artery disease, tumour size, and previous hypertension history were significantly associated with intraoperative hemodynamic instability. The multivariate logistic regression analysis showed that tumour size and previous hypertension history were independent risk factors for intraoperative hemodynamic instability. CONCLUSION: Tumour size and previous hypertension history were associated with hemodynamic instability during laparoscopic resection of pheochromocytoma.

Comparison of lateral transperitoneal and retroperitoneal approaches for homolateral laparoscopic adrenalectomy.

BACKGROUND: There is a lack of data regarding the appropriateness of transperitoneal and retroperitoneal approaches for homolateral laparoscopic adrenalectomy. The aim of this study is to compare lateral transperitoneal and retroperitoneal approach for left-sided and right-sided laparoscopic adrenalectomy respectively. METHODS: Between January 2014 and December 2019, 242 patients underwent left-sided and 252 patients underwent right-sided laparoscopic adrenalectomy. For left side, transperitoneal approach was used in 132 (103 with tumors < 5 cm and 29 with tumors ≥ 5 cm) and retroperitoneal approach in 110 (102 with tumors < 5 cm and 8 with tumors ≥ 5 cm). For right side, transperitoneal approach was used in 139 (121 with tumors < 5 cm and 18 with tumors ≥ 5 cm) and retroperitoneal approach in 113 (102 with tumors < 5 cm and 11 with tumors ≥ 5 cm). Patient characteristics and perioperative outcomes were recorded. For each side, both approaches were compared for tumors < 5 cm and ≥ 5 cm respectively. RESULTS: For left-sided tumors < 5 cm, transperitoneal approach demonstrated shorter operative time, less blood loss and longer time to oral intake. For left-sided tumors ≥ 5 cm, the peri-operative data of both approaches was comparable. For right-sided tumors < 5 cm, transperitoneal approach demonstrated shorter operative time and less blood loss. For right-sided tumors ≥ 5 cm, the peri-operative data was comparable. CONCLUSIONS: Lateral transperitoneal and retroperitoneal approach are both effective for laparoscopic adrenalectomy. Lateral transperitoneal approach is faster with less blood loss for tumors < 5 cm.

Autologous granulation tissue tubes for replacement of urethral defects: An experimental study in male rabbits.

INTRODUCTION: Tubularized urethroplasty is commonly performed in clinical practice using genital skin flaps, bladder mucosa, and buccal mucosa. However, the long-term effects are not satisfying, and donor site morbidities remain a problem. Besides, those grafts are unavailable with malignant conditions of the urinary tract, a history of lichen sclerosis, or oral disease. OBJECTIVE: An autologous granulation tissue tube of any required length and diameter can be produced by implanting foreign objects subcutaneously (Summary Fig.). The current study aimed to investigate to what extent of length this fully autologous tissue could be used for tubularized urethroplasty, satisfying urethral patency and tissue regeneration, in male rabbits. STUDY DESIGN: Twenty-seven New Zealand male rabbits were randomly divided into three groups. Silastic tubes were implanted subcutaneously in Group 1 and Group 2. By 2 weeks the granulation tissue encapsulating the tubes was harvested. In Group 1, pendulous urethral segments of 1 cm were excised, and urethroplasty was performed with the granulation tissue tube in an end-to-end fashion. In Group 2, a pendulous urethral segment of 1.5 cm was replaced with the tissue tube. In Group 3, a pendulous urethral defect of 1 cm was repaired by re-anastomosis as control. Serial urethrograms were performed at 1, 2 and 6 months postoperatively. Meanwhile, the neo-urethra were harvested and analyzed grossly and histologically. RESULTS: The urethrograms showed that all animals in Group 1 maintained a wide urethral caliber. In contrast, animals in Group 2 and Group 3 developed progressive strictures. Histologically, an intact urothelium with one to two cell layers lined the graft by 1 month, which was surrounded by increasing organized smooth muscle in Group 1. By 6 months, the grafts were completely integrated into native urethra. Nevertheless, extensive fibrosis occurred in Group 2 and Group 3. DISCUSSION: The tissue successfully maintained patency and guided urethral regeneration across a distance of 1 cm. As an epithelium-free graft, the tissue showed better results than acellular matrix for tubularized urethroplasty compared with previous studies. Nevertheless, several limitations existed: (1) the urethral defect was created in healthy urethra, which could not fully simulate the clinical situation; (2) as a small animal model, rabbit was less informative for clinical problems; (3) the tissue was inadequate for long segmental urethral replacement. Further study is needed before the procedure is used clinically. CONCLUSION: An autologous granulation tissue tube grown subcutaneously could be successfully used to repair urethral defects of 1 cm in male rabbits.

Tubularized urethral replacement using tissue-engineered peritoneum-like tissue in a rabbit model.

INTRODUCTION: This study aims to investigate whether mesothelial cells could function as seed cells to construct tissue-engineered peritoneum-like tissue for urethral reconstruction in a rabbit model. MATERIALS AND METHODS: Bladder acellular matrices were prepared and trimmed to 1.5 × 1 cm. Nine male rabbits underwent omentum biopsy and autologous mesothelial cells were isolated. After in vitro expansion, the cells were seeded onto the matrices and incubated for 7 days. In 18 rabbits, a pendulous urethral segment 1.5 cm long was totally excised and urethroplasty was performed with tubularized matrices seeded with cells in 9 animals and without cells in 9 as controls. Urethrography was performed at 1, 2 and 6 months postoperatively. Meanwhile, the neourethras were harvested and analyzed grossly and histologically. RESULTS: Histological analysis of the cell-seeded grafts revealed a loose collagen matrix covered with a single layer of mesothelim. Serial urethrography indicated a wide urethral caliber without stricture formation in animals implanted with cell-seeded matrices, while all animals of the control group developed stricture. Histological analysis of the implanted cell-seeded matrices demonstrated a normal urethral architecture by 1 month, composed of multilayers of urothelium surrounded by smooth muscle bundles, which became increasingly organized with time. By 6 months, the neourethra could be hardly distinguished from native urethra both grossly and histologically. CONCLUSIONS: Autologous mesothelial cells could be successfully used as seed cells for tubularized urethral reconstruction in male rabbits.

Ureteral reconstruction using autologous tubular grafts for the management of ureteral strictures and defects: an experimental study.

OBJECTIVE: To investigate whether the peritoneal cavity could function as a bioreactor to produce autologous tubular grafts for ureteral reconstruction in beagles. MATERIALS AND METHODS: 8-Fr Silastic tubes were implanted into the peritoneal cavities of 6 female beagles. At 3 weeks, the tubes were harvested and the tubular tissue covering the tubes was gently everted. A segment 3 cm in length of the right mid-ureter, involving two thirds of its diameter, was removed parallel to the ureteral axis, leaving a third of the ureteral wall. A 5-Fr double-J stent was inserted into the ureter through the created defect, and two thirds of the graft were anastomosed to both edges of the ureteral defect. One third of the graft was overlapped with the retained normal ureter and anastomosed to the external surface of the lumens. Thus, the graft was partly encapsulated by the remainder of ureteral wall. The stent was maintained for 6 weeks and removed. Excretory urography was performed at 8 (n = 3) and 12 weeks (n = 3), postoperatively. Meanwhile, the neoureter was harvested and analyzed. The left ureter served as the control and a simple intubated ureterotomy was performed. RESULTS: Histological analysis of the tubular tissue demonstrated transversely arranged myofibroblasts and an outer layer of mesothelium. The tissue was easily everted and transplanted as a ureteral graft. Eight weeks postoperatively, the neoureter demonstrated normal ureteral architecture, composed of multilayers of urothelium surrounded by smooth muscle bundles, which became increasingly organized with time. Excretory urography indicated no stenosis or hydronephrosis. CONCLUSIONS: These results show that autologous tubular tissue grown within the recipients' peritoneal cavity can be used for ureteral reconstruction in the beagle model.

Comparison of the transperitoneal and a semi-open retroperitoneal approach for right-sided laparoscopic donor nephrectomy.

BACKGROUND: To investigate whether the retroperitoneal or transperitoneal approach is preferable for right-sided laparoscopic donor nephrectomy (R-LDN). MATERIAL/METHODS: We retrospectively compared the donor and recipient outcomes of R-LDNs performed with a standard transperitoneal approach (n=21) or a semi-open retroperitoneal approach (n=32). RESULTS: Patient demographics were similar between groups. The semi-open retroperitoneal group had shorter operative time (89.5 min vs. 105 min, p<0.001), shorter WIT (102 s vs. 120 s, p<0.001), and longer renal veins (2.5 cm vs. 2.2 cm, p<0.001). No conversions to open procedures occurred. There were no significant differences in the blood loss, length of hospital stay, or donor complication rate between the 2 groups. All grafts functioned adequately, and there were no significant differences in graft function, first-week hemodialysis, and serum creatinine level at discharge between the 2 groups The recipient complication rate was similar between the 2 groups (9.4% vs. 9.5%, p=0.986). CONCLUSIONS: The semi-open retroperitoneal approach is safe and effective for R-LDN. Further study is required to evaluate long-term graft function.

Peritoneal cavity as bioreactor to grow autologous tubular urethral grafts in a rabbit model.

PURPOSE: To investigate whether peritoneal cavity could function as bioreactor to produce autologous tubular grafts for urethral reconstruction in male rabbits. METHODS: 8Fr silastic tubes were implanted into peritoneal cavities of nine male rabbits. By 2 weeks, tubes were harvested and the tubular tissue covering the tubes was everted. A pendulous urethral segment of 1.5 cm long was totally excised and urethroplasty was performed with the everted tubular tissue in an end-to-end fashion. Another nine male rabbits underwent the same urethral resection and re-anastomosis as controls. Urethrography was performed at 1, 2 and 6 months postoperatively. Meanwhile, the neo-urethra were harvested and analyzed grossly and histologically. RESULTS: Histological analysis of the tubular tissue demonstrated transversely arranged myofibroblasts embedded in homogeneous collagen bundles and an outer layer of mesothelium. The tissue was easily everted and successfully transplanted as a urethral graft. Serial urethrography indicated no stricture or diverticula formation. While all animals of the control group developed stricture. Histological analysis of the neo-urethra demonstrated normal urethral architecture by 1 month, composed of multi-layers of urothelium surrounded by smooth muscle bundles, which became increasingly organized with time. By 6 months, the neo-urethra could be hardly distinguished from native urethra both grossly and histologically. CONCLUSIONS: These results show that the autologous tissue grown within the recipients' peritoneal cavity can be used successfully for tubularized urethral reconstruction in male rabbits.