The learning curve for modified hand-assisted retroperitoneoscopic living donor nephrectomy.

BACKGROUND: We aimed to introduce our modified hand-assisted retroperitoneoscopic living donor nephrectomy (HARPLDN) technique and define the learning curve. METHODS: One hundred thirty-eight kidney donors who underwent modified HARPLDN by the same surgeon between May 2015 and March 2022 were included. A cumulative sum (CUSUM) learning curve analysis was performed with the total operation time as the study outcome. RESULTS: In total, the mean operative time was 138.2 ± 32.1 min. The median warm ischemic time (WIT) and estimated blood loss were 90 s and 50 ml, respectively. The learning curve for the total operative time was best modeled as a second-order polynomial with the following equation: CUSUMOT (min) = (-0.09 case number2) + (12.88 case number) - 67.77 (R2 = 0.7875; p<0.05). The CUSUM learning curve included the following three unique phases: phase 1 (the initial 41 cases), representing the initial learning curve; phase 2 (the middle 43 cases), representing expert competence; and phase 3 (the final 54 cases), representing mastery. The overall 6-month graft survival rate was 99.3%, with 94.9% immediate onset of graft function without delayed graft function and 0.7% ureteral complications. CONCLUSIONS: Our modified method is safe and effective for living donor nephrectomy and has the advantages of a shorter operating time and optimized WIT. The surgeon can become familiar with the modified HARPLDN after 41 cases and effectively perform the next 97 cases.

Preoperative Risk Factor Analysis of Prolonged Retroperitoneoscopic Radical Nephrectomy.

BACKGROUND: This study aimed to investigate the preoperative risk factors for prolonged operating time in retroperitoneoscopic radical nephrectomy (RRN) for renal cell carcinoma (RCC). METHODS: We retrospectively reviewed patients treated for RRN between January 2015 and December 2021. Clinical data, including radiological findings such as visceral fat area (VFA), subcutaneous fat area (SFA), and posterior perirenal fat thickness (PFT) were collected. The operating time for RRN was analyzed using univariate and multivariate logistic regression analyses. RESULTS: A total of 79 patients were included. The median age was 66 (range: 28-88) years and 48 (60.8%) had right-sided tumors. The median tumor size was 52 (range: 12-100) mm. Median BMI, VFA, SFA, and posterior PFT were 22.9 (range: 16.3-42.2) kg/m2, 102 (range: 14-290) cm2, 124 (range: 33-530) cm2, and 6 (range: 1-35) mm. The median operating time was 248 (range: 140-458) min. Univariate logistic regression analyses revealed that a right tumor (p=0.046), tumor size >7 cm (p=0.010), and posterior PFT >25 mm (p=0.006) were preoperative risk factors for prolonged operating time in RRN. Multivariate logistic regression analyses revealed that a posterior PFT of >25 mm was an independent preoperative risk factor for prolonged operating time for RRN (p=0.008, OR: 7.29, 95% CI: 1.69-31.5). CONCLUSIONS: A posterior PFT >25 mm was an independent preoperative risk factor for the operating time of RRN. In RRN, for patients with a posterior PFT >25 mm, surgeons should develop surgical strategies, including the selection of a transperitoneal approach to surgery, to avoid prolonging the operating time.

Single Port Robotic Nephrectomy via lower anterior retroperitoneal approach: feasible, safe and effective option in surgically complex patients.

PURPOSE: Minimally invasive radical nephrectomy is often preferred for larger renal tumours not suitable for partial nephrectomy (1). When performed with a multiport robot, the procedure is routinely performed with a transperitoneal approach, with recent studies highlighting important factors for surgical outcomes, including predictive factors (2), segmental artery unclamping techniques (3), and comparisons of robotic techniques (4). This video shows that SP Robot-Assisted Radical Nephrectomy (RARN) via a lower anterior approach is valuable in challenging cases. MATERIALS AND METHODS: We performed SP-RARN on two complex patients using a retroperitoneal lower anterior approach. The first patient, a 54-year-old female with a BMI of 36.8 kg/m², had a ventral hernia and bowel obstruction history, with a 9 cm right middle kidney mass. The second patient, a 58-year-old male with a BMI of 31.19 kg/m², had ESRD and was on peritoneal dialysis for 8 years, with a 3.4x3.7 cm mass in the right superior pole, suspected to be RCC. The surgical technique is detailed in the video. RESULTS: Both procedures were successful, with operative times of 173 and 203 minutes and blood loss of 150 mL. No complications occurred. Patients were discharged after 31 and 38 hours, respectively. Histopathology confirmed RCC. At the 3-month follow-up, no complications or readmissions were reported. Second patient continued peritoneal dialysis without issues. CONCLUSION: Retroperitoneal SP-RARN via the lower anterior approach avoids the peritoneal cavity, making it suitable for certain patients. In these patients, more so than in others, this procedure is feasible, safe, and less morbid than the standard multiport approach.

Transvaginal natural orifice transluminal endoscopic surgery (VNOTES) retroperitoneal sentinel lymph node BIOPSY compared with conventional laparoscopy in patients with endometrial cancer.

INTRODUCTION: To explore the possibility of treatment with VNOTES sentinel lymph node dissection concept in patients with endometrial cancer. METHODS: Patients who underwent VNOTES sentinel lymph node biopsy with the Comba modification were compared to patients who underwent conventional laparoscopic sentinel lymph node biopsy performed by the same surgical team. A total of 38 patients who underwent sentinel lymph node biopsy + total laparoscopic hysterectomy and bilateral salpingo-oophorectomy (BSO) were compared with 19 patients who underwent VNOTES retroperitoneal sentinel lymph node biopsy + hysterectomy and BSO. Surgical steps were described. RESULTS: The average operation time, perioperative blood loss, the number of sentinel lymph nodes, presence of complications, and preoperative-postoperative hemoglobin-hematocrit differences, tumor stages, grades, largest tumor diameter, depths of invasion, and histological subtypes were similar in both the VNOTES and conventional laparoscopy groups. The postoperative pain scores were lower and the hospital stay was shorter in the VNOTES group than in the conventional laparoscopy group. No disease recurrence had been detected in either group at the time of writing. CONCLUSION: Compared to conventional laparoscopy, sentinel lymph node biopsy with the VNOTES technique provides similar surgical results and is more advantageous in terms of postoperative pain and hospital length of stay.

Safety and graft outcome of right retroperitoneal laparoscopic donor nephrectomy for living donor kidney transplantation: A comparison with left retroperitoneal laparoscopic donor nephrectomy.

INTRODUCTION: The left kidney is often preferred for living donor kidney transplantation because of its anatomical advantages. However, the right kidney may be procured due to donor conditions. Few studies have assessed the safety and graft outcome of right retroperitoneal laparoscopic donor nephrectomy (RDN). This study aimed to compare the outcomes between right and left RDN with respect to donor outcome and the graft function of recipients. METHODS: This retrospective study included 230 consecutive living donor kidney transplants performed at our institution between May 2019 and March 2023. We reviewed the outcomes of kidney transplant in the right and left kidneys after RDN. RESULTS: A total of 230 living donor kidney transplants were performed, with 32 donors receiving right RDN (right RDN group) and 198 donors receiving left RDN (left RDN group). The renal veins and ureters were significantly shorter in the right RDN group than in the left RDN group (both p < .001). Donor operation and warm ischemia time were significantly longer in the right RDN group than in the left RDN group (p = .012 and p < .001, respectively). None of the groups exhibited any cases of delayed graft function owing to donor-related reasons. Perioperative changes in the estimated glomerular filtration rate of recipients and death-censored graft survival were not significantly different between the two groups. CONCLUSIONS: In RDN, the outcomes of right donor nephrectomy were comparable to those of left donor nephrectomy in terms of donor safety and recipient renal function.

Total laparoscopic hysterectomy with posterior cul-de-sac obliteration: step-by-step procedures based on precise anatomical landmarks.

BACKGROUND: Dense adhesion due to severe endometriosis between the posterior cervical peritoneum and the anterior sigmoid or rectum obliterates the cul-de-sac and distorts normal anatomic landmarks. Surgery for endometriosis is associated with severe complications, including ureteral and rectal injuries, as well as voiding dysfunction. It is important to develop the retroperitoneal avascular space based on precise anatomical landmarks to minimize the risk of ureteral, rectal, and hypogastric nerve injuries. We herein report the anatomical highlights and standardized and reproducible surgical steps of total laparoscopic hysterectomy for posterior cul-de-sac obliteration. OPERATIVE TECHNIQUE: We approach the patient with posterior cul-de-sac obliteration using the following five steps. Step 1: Preparation (Mobilization of the sigmoid colon and bladder separation from the uterus). Step 2: Development of the lateral pararectal space and identification of the ureter. Step 3: Isolation of the ureter. Step 4: Development of the medial pararectal space and separation of the hypogastric nerve plane. Step 5: Reopening of the pouch of Douglas. CONCLUSION: Surgeons should recognize the importance of developing the retroperitoneal avascular space based on precise anatomical landmarks, and each surgical step must be reproducible.

Maximizing Success: An Overview of Optimizing the Ovarian Tissue Transplantation Site.

Ovarian tissue cryopreservation and transplantation (OTCT) has emerged in recent years as a potential method for reversing abnormal endocrine and reproductive functions, particularly in patients receiving gonadotoxic cancer treatments having longer survival rates. From its first rodent experiments to human trials, OTCT has evolved tremendously, opening new windows for further utilization. Since then, significant progress has been achieved in terms of techniques used for surgical removal of the tissue, optimal fragment size, freezing and thawing procedures, and appropriate surgical sites for the subsequent reimplementation of the graft. In addition, various approaches have been proposed to decrease the risk of ischemic injury, which is the leading cause of significant follicle loss during neo-angiogenesis. This review aims to discuss the pros and cons of ovarian and retroperitoneal transplantation sites, highlighting the justifications for the viability and efficacy of different transplantation sites as well as the potential advantages and drawbacks of retroperitoneal or preperitoneal area.

Comparison of lateral flank approach and low anterior access for single port (SP) retroperitoneal partial nephrectomy: an analysis from the single port advanced research consortium (SPARC).

Single Port (SP) robotic partial nephrectomy (RPN) can be performed via retroperitoneal and transperitoneal approach. We aim to compare outcomes of two commonly described incisions for retroperitoneal SP RPN: lateral flank approach (LFA) and low anterior access (LAA). We performed a retrospective study of patients who underwent SP retroperitoneal RPN from 2018 to 2023 as part of a large multi-institute collaboration (SPARC). Baseline demographic, clinical, tumor-specific characteristics, and perioperative outcomes were compared using χ2, t test, Fisher exact test, and Mann-Whitney U test. Multivariable analyses were conducted using robust and logistic regressions. A total of 70 patients underwent SP retroperitoneal RPN, with 44 undergoing LAA. Overall, there were no significant differences in baseline characteristics between the two groups. The LAA group exhibited significantly lower median RENAL scores (8 vs. 5, p < 0.001) and more varied tumor locations (p = 0.002). In the bivariate analysis, there were no statistically significant differences in ischemia time, estimated blood loss, or complication rates between the groups. However, the LAA group had longer operative times (101 vs. 134 min, p < 0.001), but was more likely to undergo a same-day discharge (p < 0.001). When controlling for other variables, LAA was associated with shorter ischemia time (p = 0.005), but there was no significant difference in operative time (p = 0.348) and length of stay (p = 0.122). Both LFA and LAA are acceptable approaches for SP retroperitoneal RPN with comparable perioperative outcomes. This early data suggests the LAA is more versatile for varying tumor locations; however, larger cohort studies are needed to ascertain whether there is an overall difference in patient recovery.

Totally retroperitoneal approach for robot-assisted nephroureterectomy with bladder cuff without repositioning.

INTRODUCTION: Robot-assisted nephroureterectomy (RANU) for upper urinary tract urothelial carcinoma is typically performed via the transperitoneal approach because of limited surgical space. However, a retroperitoneal approach may be preferable in patients with a history of abdominal surgery or in those in whom pelvic lymph node dissection is unnecessary. MATERIALS AND SURGICAL TECHNIQUES: RANU via the retroperitoneal approach was selected for two patients diagnosed with high-grade upper urothelial carcinoma with a history of abdominal surgery. Nephrectomy was performed in the 90° flank position, and the bed was tilted at 20°. The retroperitoneal space was extended, and the robot trocar was subsequently repositioned in the left lower quadrant. After redocking the robot, the distal ureter was dissected, and the bladder cuff was resected en bloc along with the kidney and the ureter. Neither patient had any complications within 3 months postoperatively. DISCUSSION: By devising a new technique for trocar placement, total retroperitoneal RANU without repositioning was possible, even in a small patient.

Usefulness of hand-assisted retroperitoneal laparoscopic radical nephrectomy for extreme obese patients -a case report.

We report a case of retroperitoneal laparoscopic radical nephrectomy (LRN) in which the addition of a hand port was necessary and effective. A 52-year-old man with obesity (BMI 40.6 kg/m2) was diagnosed with a 52-mm left renal cell carcinoma (cT1bN0M0). To avoid thick subcutaneous and visceral fat in the abdomen, we selected LRN using a retroperitoneal approach with four ports in the kidney position. During surgery, a large amount of flank pad and perirenal fat prevented us from securing a sufficient surgical field through traction of the kidney with a retractor. A pure laparoscopic procedure was not feasible;therefore, we added a hand port. Subsequently, we removed the flank pad from the hand port and secured the surgical field by tracing the kidney manually. Finally, hand-assisted LRN was completed without an open conversion. In retroperitoneal LRN, we rarely encounter patients for whom a pure laparoscopic procedure is not feasible because of the large amount of flank pad or perirenal fat. It is important to preoperatively confirm not only the BMI but also the amount of flank pad and perirenal fat on imaging. Hand-assisted LRN via the retroperitoneal approach can be safely performed even in extremely obese patients. J. Med. Invest. 71 : 187-190, February, 2024.

A prospective case series to evaluate subcostal nerve injury with high-resolution ultrasound in posterior retroperitoneoscopic adrenalectomy.

BACKGROUND: Posterior retroperitoneoscopic adrenalectomy has several advantages over transabdominal laparoscopic adrenalectomy regarding operating time, blood loss, postoperative pain, and recovery. However, postoperatively several patients report chronic pain or hypoesthesia. We hypothesized that these symptoms may be the result of damage to the subcostal nerve, because it passes the surgical area. METHODS: A prospective single-center case series was performed in adult patients without preoperative pain or numbness of the abdominal wall who underwent unilateral posterior retroperitoneoscopic adrenalectomy. Patients received pre- and postoperative questionnaires and a high-resolution ultrasound scan of the subcostal nerve and abdominal wall muscles was performed before and directly after surgery. Clinical evaluation at 6 weeks was performed with repeat questionnaires, physical examination, and high-resolution ultrasound. Long-term recovery was evaluated with questionnaires, and photographs from the patients were examined for abdominal wall asymmetry. RESULTS: A total of 25 patients were included in the study. There were no surgical complications. Preoperative visualization of the subcostal nerve was possible in all patients. At 6 weeks, ultrasound showed nerve damage in 15 patients, with no significant association between nerve damage and postsurgical pain. However, there was a significant association between nerve damage and hypoesthesia (p = 0.01), sensory (p < 0.001), and motor (p < 0.001) dysfunction on physical examination. After a median follow-up of 18 months, 5 patients still experienced either numbness or muscle weakness, and one patient experienced chronic postsurgical pain. CONCLUSION: In this exporatory case series the incidence of postoperative damage to the subcostal nerve, both clinically and radiologically, was 60% after posterior retroperitoneoscopic adrenalectomy. There was no association with pain, and the spontaneous recovery rate was high.

Long-term outcome of retroperitoneoscopic partial versus total adrenalectomy in patients with Cushing's syndrome.

BACKGROUND: We analyze the long-term outcome of surgery for Cushing's syndrome (CS) and the influence of the extent of surgical resection on the duration of postoperative cortisone substitution. METHODS: One-hundred forty-one patients (129 female, 12 males; mean age: 45.7 ± 12.8 years) operated between January 2000 to June 2020 were included in the analysis. Patients suffered from manifest (124) or subclinical (17) CS due to benign unilateral adrenal neoplasia. All tumors were removed by the posterior retroperitoneoscopic approach. 105 patients had total (TA) and 36 partial (PA) adrenalectomies. All patients were discharged with ongoing corticosteroid supplementation therapy. RESULTS: Follow-up data could be obtained for 83 patients. Twenty-four (1 male, 23 females; mean age 42.3 years) underwent PA and 59 TA (6 males, 53 females; mean age 44.6 years). Mean follow-up time was 107 ± 68 months (range: 6-243 months). The median duration of postoperative corticosteroid therapy was 9.5 months after PA and 11 months after TA (p = 0.1). Significantly, more patients after total adrenalectomy required corticosteroid therapy for more than 24 months (25% vs. 4%; p = 0.03). Recurrent ipsilateral disease occurred in one case after partial adrenalectomy and was treated by completion adrenalectomy. A case of contralateral recurrence associated with subclinical Cushing's syndrome was observed after total adrenalectomy. CONCLUSIONS: The risk of local recurrence after partial adrenalectomy in CS is low. Cortical-sparing surgery may shorten corticosteroid supplementation therapy after surgery.

Versatility of Single Port Retroperitoneal Low Anterior Access: Early Outcomes in Multiple Procedures.

Purpose: This study aimed to assess early outcomes of the single port (SP) robotic low anterior access (LAA) for all upper urinary tract surgeries. In addition, it aimed to explore the impact of clinical factors, notably Body Mass Index (BMI), on post-operative outcomes and length of hospital stay. Materials and Methods: Overall, 76 consecutive patients underwent SP robotic surgery with LAA involving all upper urinary tract pathologies, with data collected prospectively. Baseline characteristics, intra- and post-operative outcomes, pain levels, and opioid use were analyzed. Statistical methods, including logistic regression and locally weighted scatterplot smoothing analysis, were used to assess same-day discharge (SDD) predictors and the association between BMI and SDD probability. According to the Institutional Review Board (IRB) protocol, only data recorded in our electronic medical record system was included. Results: Ten different procedures were performed with LAA, with no need for conversion to open surgery and complication rates in line with the literature (30 days: 5%, 90 days: 6.6%). Notably, 77.6% of patients were discharged on the same day. A significant association was found between BMI and prolonged hospital stay, particularly in obese patients (BMI ≥30 kg/m2). Post-operative pain was generally low (median VAS: 4), with over 70% discharged without opioid prescriptions. Conclusions: The novel LAA is a versatile approach for various upper urinary tract surgeries, including in obese patients. While achieving satisfactory post-operative outcomes, increased BMI correlated with a reduced likelihood of SDD. Further studies, including larger cohorts and multicenter collaborations, are warranted to explore anesthesiologic management and validate these findings.

A novel mini-retractor for retroperitoneal laparoscopic partial nephrectomy.

BACKGROUND: Retroperitoneal partial nephrectomy (RLPN) is the premier treatment for localized renal tumors despite narrow operation space. Many efforts have been taken to facilitate the operation of RLPN, but the optimal resolution remains debatable. OBJECTIVE: To explore the feasibility of using Mini-lap to improve workspace and surgical vision in RLPN. DESIGN, SETTING, AND PARTICIPANTS: A multicenter retrospective review of 51 patients who underwent RLPN with Mini-lap from January 2018 to December 2020 was conducted. SURGICAL PROCEDURE: Standard RLPN under three poles was performed in all cases. We highlighted the usage of Mini-lap (Teleflex Minilap percutaneous Surgical System) as a novel retractor in RLPN. OUTCOME AND MEASUREMENTS AND STATICAL ANALYSIS: Demographics, preoperative, intraoperative, and postoperative outcomes were assessed. RESULTS AND LIMITATIONS: All 51 cases completed RLPN with three ports successfully and no conversion to open surgery. The mean diameter of tumors was (3.53 ± 1.05) cm, in which 62.7% (32/51) were located anteriorly. The operation time and warm ischemic time (WIT) were (86.7 ± 15.9) min and (25.6 ± 5) min respectively. Minor complications (Clavien grade 1-2) occurred in 6 cases. The limitations were small sample size, retrospective design, and absence of control. CONCLUSIONS: Mini-lap could be used as a mini-retractor in RLPN, sparing extra assistant ports, expanding workspace, and optimizing vision. PATIENT SUMMARY: With highlights of larger workspace and less instrument interference, mini-lap could be applied in retroperitoneal laparoscopic partial nephrectomy.

vNOTES surgical staging for endometrial carcinoma in overweight patients: a case series.

OBJECTIVES: The purpose of this study is to show the feasibility and surgical outcome of vNOTES retroperitoneal dissection and isolation of sentinel lymph nodes in overweight and obese patients with endometrial cancer. MATERIALS AND METHODS: Four patients had undergone pelvic lymphadenectomy with a sentinel lymph node. Three patients were overweight, and one was obese with a BMI of 34.6 kg/m2. By using NMR mode sentinel lymph node was visualized, excised and marked separately for pathohistological analysis from the rest of the visualized lymph nodes that were then consecutively excised. RESULTS: The mean number of overall excised lymph nodes was 12.5, and the mean number on the right side was 5.75 and 6.25 on the left side. There were no metastases verified in the pathohistological evaluation. CONCLUSION: vNOTES retroperitoneal isolation of sentinel lymph nodes is good alternative and has its benefits, especially in overweight and obese patients with satisfying low intra- and postoperative complications.

A novel method of tunneling retroperitoneoscopic adrenalectomy: a prospective study.

BACKGROUND: To introduce the surgical technique and our team's extensive experience with tunnel method in laparoscopic adrenalectomy. METHODS: From July 2019 to June 2022, we independently designed and conducted 83 cases of " Tunnel Method Laparoscopic Adrenalectomy," a prospective study. There were 45 male and 38 female patients, ages ranged from 25 to 73 years(mean: 44.6 years).The cases included 59 adrenal cortical adenomas, 9 pheochromocytomas, 6 cysts, 4 myelolipomas, 1 ganglioneuroma, and 4 cases of adrenal cortical hyperplasia. In terms of anatomical location, there were 39 cases on the left side, 42 on the right side, and 2 bilateral cases. Tumor diameters ranged from 0.6 to 5.9 cm(mean: 2.9 cm). Utilizing ultrasound monitoring, percutaneous puncture was made either directly to the target organ or its vicinity, and the puncture path was manually marked. Then, under the direct view of a single-port single-channel laparoscope, the path to the target organ in the retroperitoneum or its vicinity was further delineated and separated. This approach allowed for the insertion of the laparoscope and surgical instruments through the affected adrenal gland, thereby separating the surface of the target organ to create sufficient operational space for the adrenalectomy. RESULTS: All 83 surgeries were successfully completed. A breakdown of the surgical approach reveals that 51 surgeries were done using one puncture hole, 25 with two puncture holes, and 7 with three puncture holes. The operation time ranged from 31 to 105 min (mean: 47 min), with a blood loss of 10 to 220mL (mean: 40 mL). Notably, there were no conversions to open surgery and no intraoperative complications. Postoperative follow-up ranged from 6 to 28 months, during which after re-examination using ultrasound, CT, and other imaging methods, there were no recurrences or other complications detected. CONCLUSIONS: The completion of the tunnel method laparoscopic adrenalectomy represents a breakthrough, transitioning from the traditional step-by-step separation of retroperitoneal tissues to reach the target organ in conventional retroperitoneoscopic surgery. This method directly accesses the target organ, substantially reducing the damage and complications associated with tissue separation in retroperitoneoscopic surgery, As a result, it provides a new option for minimally invasive surgery of retroperitoneal organs and introduces innovative concepts to retroperitoneoscopic surgery.

Optical Trocar Access for Retroperitoneal Robotic-Assisted Pyeloplasty in Children with Ureteropelvic Junction Obstruction.

Purpose: Retroperitoneal robotic-assisted pyeloplasty (ret-RAP) for ureteropelvic junction obstruction (UPJO) requires a larger retroperitoneal space (RS) to maintain specified distances between robotic (da Vinci) trocars and between trocars and the region of interest. A modified closed technique (MOT) and conventional closed technique (COT) were compared for creating an adequate RS with optical trocars. Methods: RS access in children with UPJO who underwent ret-RAP (n = 30) was MOT (n = 15) and COT (n = 15). All patients were positioned laterally. For MOT, a 5 mm optical trocar was inserted at the angle formed between the 12th rib and the erector spinae muscles. As the trocar was advanced under direct vision, it pierced the superficial subcutaneous layer, Scarpa's fascia, lumbar fascia, internal/external oblique and transversus abdominalis muscles, and the posterior renal fascia. Once in the RS, the tip of the scope was used for blunt dissection of perirenal fat, the tip was withdrawn until it was outside the perirenal fascia, and used to dissect toward the anterior abdomen in the pararenal fat layer. Results: Ages and weights at ret-RAP were similar (MOT: 5.6 ± 1.8 years versus COT: 7.8 ± 4.6 years; MOT: 20.6 ± 10.1 kg versus COT: 27.6 ± 13.9 kg). Times for RS access were similar (MOT: 1.6 ± 0.5 minutes versus COT: 1.9 ± 0.7 minutes), but RS expansion was significantly quicker in MOT (32.3 ± 8.7 minutes versus 52.0 ± 15.1 minutes; P < .001). Peritoneal injury caused carbon dioxide leakage in 4 of 15 COT cases and 0 of 15 MOT cases. Conclusion: RS expansion with MOT was safer because there were no peritoneal injuries and MOT was quicker than COT.

Successful laparoscopic resection of retroperitoneal ectopic pregnancy between the abdominal aorta and inferior vena cava: A case report.

Retroperitoneal ectopic pregnancies are extremely rare; only a few cases having been reported. Here, we report laparoscopic removal of an asymptomatic retroperitoneal ectopic pregnancy from a 29-year-old woman who was referred to our hospital for a suspected ectopic pregnancy. Transvaginal ultrasound did not reveal a gestational sac in the uterus or pelvic cavity. However, abdominal contrast-enhanced computer tomography showed a gestational sac between the abdominal aorta and inferior vena cava. On laparoscopy, the gestational sac was confirmed to be in this retroperitoneal location and successfully removed with minimal bleeding. Histopathologic examination revealed chorionic villi surrounded by lymphatic tissue, suggesting lymphatic spread of the retroperitoneal ectopic pregnancy. In summary, contrast-enhanced computer tomography is very useful for locating the site of pregnancy in women suspected of having a retroperitoneal ectopic pregnancy. Timely diagnosis of a retroperitoneal ectopic pregnancy before bleeding occurs can enable their safe laparoscopic removal.

Retroperitoneal Laparoscopic Debridement and Drainage for Pancreatic Abscess.

In patients with severe necrotizing pancreatitis, pancreatic necrosis and secondary infection of surrounding tissues can quickly spread to the whole retroperitoneal space. Treatment of pancreatic abscess complicating necrotizing pancreatitis is difficult and has a high mortality rate. The well-accepted treatment strategy is early debridement of necrotic tissues, drainage, and postoperative continuous retroperitoneal lavage. However, traditional open surgery has several disadvantages, such as severe trauma, interference with abdominal organs, a high rate of postoperative infection and adhesion, and hardness with repeated debridement. The retroperitoneal laparoscopic approach has the advantages of minimal invasion, a better drainage route, convenient repeated debridement, and avoidance of the spread of retroperitoneal infection to the abdominal cavity. In addition, retroperitoneal drainage leads to fewer drainage tube problems, including miscounting, displacement, or siphon. The debridement and drainage of pancreatic abscess tissue via the retroperitoneal laparoscopic approach plays an increasingly irreplaceable role in improving patient prognosis and saving healthcare resources and costs. The main procedures described here include laying the patient on the right side, raising the lumbar bridge and then arranging the trocar; establishing the pneumoperitoneum and cleaning the pararenal fat tissues; opening the lateral pyramidal fascia and the perirenal fascia outside the peritoneal reflections; opening the anterior renal fascia and entering the anterior pararenal space from the rear; clearing the necrotic tissue and accumulating fluid; and placing drainage tubes and performing postoperative continuous retroperitoneal lavage.

A Machine Learning Model to Predict the Histology of Retroperitoneal Lymph Node Dissection Specimens.

BACKGROUND/AIM: While post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) benefits patients with teratoma or viable germ cell tumors (GCT), it becomes overtreatment if necrosis is detected in PC-RPLND specimens. Serum microRNA-371a-3p correctly predicts residual viable GCT with 100% sensitivity; however, prediction of residual teratoma in PC-RPLND specimens using current modalities remains difficult. Therefore, we developed a machine learning model using CT imaging and clinical variables to predict the presence of residual teratoma in PC-RPLND specimens. PATIENTS AND METHODS: This study included 58 patients who underwent PC-RPLND between 2005 and 2019 at the University of Tsukuba Hospital. On CT imaging, 155 lymph nodes were identified as regions of interest (ROIs). The ResNet50 algorithm and/or Support Vector Machine (SVM) classification were applied and a nested, 3-fold cross-validation protocol was used to determine classifier accuracy. RESULTS: PC-RPLND specimen analysis revealed 35 patients with necrosis and 23 patients with residual teratoma, while histology of 155 total ROIs showed necrosis in 84 ROIs and teratoma in 71 ROIs. The ResNet50 algorithm, using CT imaging, achieved a diagnostic accuracy of 80.0%, corresponding to a sensitivity of 67.3%, a specificity of 90.5%, and an AUC of 0.84, whereas SVM classification using clinical variables achieved a diagnostic accuracy of 74.8%, corresponding to a sensitivity of 59.0%, a specificity of 88.1%, and an AUC of 0.84. CONCLUSION: Our machine learning models reliably distinguish between necrosis and residual teratoma in clinical PC-RPLND specimens.