Primary Retroperitoneal Lymph Node Dissection for Clinical Stage II A/B Seminomas: A Systematic Review and Meta-Analysis.

INTRODUCTION: Chemotherapy and radiation therapy are considered standard treatments for stage II seminoma patients; however, these therapies are associated with long-term toxicities. Recently, retroperitoneal lymph node dissection has emerged as an alternative strategy, and the first three phase II trials were published in 2023 with promising results. The present study conducted a systematic review and meta-analysis to evaluate this surgery as an alternative treatment for stage IIA/B seminoma patients. PURPOSE: Seminomas are the most common testicular tumors, often affecting young adult males. Standard treatments for stage II seminomas include chemotherapy and radiation therapy, but these therapies are associated with long-term toxicities. Thus, identifying alternative strategies is paramount. Herein, we conducted a systematic review and meta-analysis to appraise the efficacy and safety of retroperitoneal lymph node dissection (RPLND) for treating this condition. METHODS: We systematically searched the PubMed, Embase, and Cochrane databases for studies evaluating RPLND as a primary treatment for stage II A/B seminomas. Using a random-effects model, single proportion and means and pooled 2-year recurrence-free survival rates with hazard rates and 95% CI were calculated. RESULTS: Seven studies were included, comprising 331 males with stage II seminomas. In the pooled analysis, the recurrence rate was 17.69% (95% CI 12.31-24.75), and the 2-year RFS rate was 81% (95% CI 0.77-0.86). The complication rate was 9.16% (95% CI 6.16-13.42), the Clavien-Dindo > 2 complication rate was 8.83% (95% CI 5.76-13.31), and the retrograde ejaculation rate was 7.01% (95% CI 3.54-13.40). The median operative time was 174.68 min (95% CI 122.17-249.76 min), median blood loss was 105.91 mL (95% CI 46.89-239.22 mL), and patients with no evidence of lymph node involvement ranged from 0-16%. CONCLUSIONS: Primary RPLNDs for treating stage IIA/B seminomas have favorable RFS rates, with low complication and recurrence rates. These findings provide evidence that this surgery is a viable alternative therapy for these patients.

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.

Outcomes of minimal access retroperitoneal para-aortic lymphadenectomy in patients with locally advanced cervical cancer.

BACKGROUND: To evaluate outcomes of laparoscopic retroperitoneal para-aortic lymphadenectomy for stage 1b3-3b cervical cancer. METHODS: Pathology databases searched for all para-aortic lymphadenectomy cases 2005-2016. Descriptive statistics were used to analyse baseline characteristics, cox models for treatment affect after accounting for variables, and Kaplan Meier curves for survival (STATA v15). RESULTS: 191 patients had 1b3-3b cervical cancer of which 110 patients had Para-aortic lymphadenectomy. 8 (7.3%) patients stage 1b3, 82 (74.6%) stage 2b, and 20 (18.1%) stage 3b cervical cancer. Mean lymph node count 11.7 (SD7.6). The intra-operative and post-operative 30 day complication rates were 8.8% (CI: 4.3%, 15.7%) and 5.3% (CI: 1.9%, 11.2%) respectively.Para-aortic nodes were apparently positive on CT/MRI in 5/110 (5%) cases. Cancer was found in 10 (8.9%, CI: 4.3%, 15.7%) cases on histology, all received extended field radiotherapy. Only 2 were identified on pre-operative CT/MRI imaging. 3 of 10 suspected node-positive cases on CT/MRI had negative histology. Para-aortic lymphadenectomy led to alteration in staging and radiotherapy management in 8 (8%, CI: 3.7%, 14.6%) patients. Mean overall survival 42.81 months (SD = 31.79 months). Survival was significantly higher for women undergoing PAN (50.57 (SD 30.7) months) compared to those who didn't (31.27 (SD 32.5) months). CONCLUSION: Laparoscopic retroperitoneal para-aortic lymphadenectomy is an acceptable procedure which can guide treatment in women with locally advanced cervical cancer.

We evaluated outcomes for patients with stage 1b3-3b cervical cancer that had lymph nodes removed prior to planning their chemoradiotherapy. There were 3 groups ­ patients that had their lymph nodes removed, those that did not and those that had their procedure abandoned so didn't have their lymph nodes removed. We looked at the lymph nodes down the microscope to see if they contained cancer and compared this to their pre-operative imaging. 8 patients had a change to their staging and treatment because they were found to have cancer in the lymph nodes. We found that the keyhole procedure to remove lymph nodes is an acceptable procedure which can guide treatment in women with locally advanced cervical cancer.

Extensive ecchymosis and retroperitoneal hemorrhage due to acquired hemophilia-A following influenza vaccination: A case report.

INTRODUCTION: Acquired hemophilia-A (AHA) is a rare but potentially life-threatening impaired coagulation disorder characterized by the development of autoantibodies against clotting factor VIII. Only a few case reports have been experienced with influenza vaccine-triggered AHA. Here, we report a case of severe hemorrhagic disorder due to AHA following influenza vaccine, which was successfully treated. PATIENT CONCERNS: The patient presented to the emergency department because of several severe, progressively worsening bruises after receiving the influenza vaccination. Consequently, the patient required intubation due to nasal-oral bleeding, which compromised the airway, and retroperitoneal hemorrhage with shock also developed. DIAGNOSIS: AHA was confirmed through a coagulation factor assay, including coagulation activity and antibody testing, which is possibly triggered by influenza vaccination. INTERVENTION: Low-dose cyclophosphamide and hydrocortisone were prescribed until activated partial thromboplastin time showed normal levels. Coagulation factor VIIa was administered, and aggressive blood transfusion was carried out concurrently to address the blood loss. OUTCOMES: The upper airway bleeding subsided and bleeding tendencies had been corrected to normal. The patient was smoothly weaned from the ventilator and recovered from critical illness. She was then discharged on the 19th day. LESSONS: The activated partial thromboplastin time mixing test can be performed immediately to establish the initial differential diagnosis and treatment plan for severe coagulopathy. AHA may be triggered by vaccination, with the hypothesis of activation of autoantibodies and molecular mimicry; this mechanism should be further studied.

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.

Spontaneous retroperitoneal haemorrhage after pulmonary endarterectomy surgery.

Spontaneous retroperitoneal hematoma (SRH) is a rare complication of anticoagulation therapy. Presentation may vary from limb paresis to hypovolemic shock due to blood loss. The optimal treatment is controversial. It can be managed conservatively or surgically. We report a case of a 73-year-old man presenting with progressively worsening abdominal pain and severe pain radiating to his left lower limb twenty-five days after his pulmonary endarterectomy (PEA) surgery. He was on anticoagulation per our institutional protocol for PEA patients. Investigations revealed a large, spontaneously occurring iliopsoas hematoma. Our patient was treated conservatively, and the SRH stabilised.

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.

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.

Overview of F18-FDG uptake patterns in retroperitoneal pathologies: imaging findings, pitfalls, and artifacts.

INTRODUCTION: Retroperitoneum can be the origin of a wide variety of pathologic conditions and potential space for disease spread to other compartments of the abdomen and pelvis. Computed tomography (CT) and magnetic resonance imaging (MRI) are often the initial imaging modalities to evaluate the retroperitoneal pathologies, however given the intrinsic limitations, F18-FDG PET/CT provides additional valuable metabolic information which can change the patient management and clinical outcomes. We highlight the features of retroperitoneal pathologies on F18-FDG PET/CT and the commonly encountered imaging artifacts and pitfalls. The aim of this review is to characterize primary and secondary retroperitoneal pathologies based on their metabolic features, and correlate PET findings with anatomic imaging. CONCLUSION: Retroperitoneal pathologies can be complex, ranging from oncologic to a spectrum of non-oncologic disorders. While crosse-sectional imaging (CT and MRI) are often the initial imaging modalities to localize and characterize pathologies, metabolic information provided by F18-FDG PET/CT can change the management and clinical outcome in many cases.

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.

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.

Modified versus three-level technique of retroperitoneal laparoscopic adrenalectomy for all patients with adrenal lesions ≤ 6cm: a retrospective, case-controlled study.

Objectives: The modified three-level technique for retroperitoneal laparoscopic adrenalectomy (RLA) has proven beneficial in the treatment of adrenal lesions in patients with BMI≥25 Kg/m2. This paper aims to summarize our institution's seven-year experience using this technique for all patients with Adrenal Lesions ≤ 6cm. Patients and methods: Between January 2016 and December 2022. The patients underwent laparoscopic adrenal surgery were categorized into Zhang's technique (ZT) (Three-level Technique) group and modified technique (MT) group. The fundamental characteristics and perioperative data were analyzed, with statistical significance set at p<0.05. Results: In total, 731 patients were stratified into two groups: ZT (n=448) and MT (n=283). Statistically significant distinctions were not detected between the two groups regarding sex, BMI, tumor location, tumor size, tumor type, or American Society of Anesthesiologists (ASA) score (p>0.05). The MT group demonstrated superior outcomes compared to the ZT group in terms of operative time, estimated blood loss, drainage volume, diet recovery time, complication rates, and postoperative hospitalization duration (p<0.05). 17 (4.34%) in the ZT group required unplanned adrenalectomy, while there was none in MT group (P<0.05). Conclusion: MT retroperitoneal laparoscopic adrenalectomy has demonstrated its benefits in the treatment of adrenal lesions across all patients with adrenal lesions ≤ 6cm, serving as a valuable point of reference for the surgical management of adrenal diseases. Patient summary: We have made modifications to the classic retroperitoneal laparoscopic adrenalectomy and achieved superior surgical outcomes, resulting in a procedure known as modified retroperitoneal laparoscopic adrenalectomy. This technique is suitable for both obese individuals and the general population with adrenal lesions ≤ 6cm.

Utilizing Video-Assisted Retroperitoneal Debridement for Retroperitoneal Abscess Following Penetrating Trauma.

Retroperitoneal abscess as a sequela of penetrating trauma can pose a difficult clinical scenario for surgeons and literature to inform decision making is sparse. It is logical to follow a "step-up" approach applied to other etiologies of infected retroperitoneal fluid collections, such as infected pancreatic necrosis and perinephric abscess. Video-assisted retroperitoneal debridement (VARD) is a well-established approach in infected pancreatic necrosis when surgical debridement is warranted. Minimally invasive retroperitoneal approaches have emerged in a broadening range of etiologies and specialties. We describe our experience utilizing VARDs in two patients that developed retroperitoneal abscesses following gunshot injuries to bowel and proximal urinary system. Both failed a conservative approach including antibiotic and percutaneous drains. Rapid improvement and subsequent discharge were observed within days of VARD procedure. We believe VARD to be a viable approach to post-trauma retroperitoneal abscesses when surgical drainage is indicated, and anatomy is favorable.

Anatomical Distribution of Sentinel Lymph Nodes Harvested by Retroperitoneal vNOTES in 34 Consecutive Patients With Early-Stage Endometrial Cancer: Analysis of 124 Lymph Nodes.

STUDY OBJECTIVE: To determine the anatomical distribution of sentinel lymph nodes (SLNs), the overall, unilateral, and bilateral detection rates, and the bilateral SLN concordance in patients with endometrial cancer (EC) mapped through a retroperitoneal transvaginal natural orifice transluminal endoscopic surgery (vNOTES) approach. DESIGN: Prospective single-center observational study. SETTING: Swiss teaching hospital. PATIENTS: Patients with EC or endometrial complex atypical hyperplasia who had undergone surgical staging with SLN mapping by a retroperitoneal vNOTES approach between October 2021 and November 2023. INTERVENTIONS: Patients were placed in a horizontal dorsal lithotomy position under general anesthesia, and indocyanine green (ICG) was injected into the cervix. Access to the retroperitoneal space was achieved through vaginal incisions. A 7 cm GelPoint V-Path Transvaginal Access Platform was used as a vNOTES port, and CO2 was insufflated to expand the retroperitoneal space. The pelvic retroperitoneal space was inspected for ICG uptake by lymph nodes. After identification, SLNs were removed and sent for definitive histological examination. MEASUREMENT AND MAIN RESULTS: A total of 34 patients were included in this study; 33 (97.1%) had a successful procedure (unilateral or bilateral mapping), and 1 (2.9%) had failed mapping. A total of 124 SLNs were identified and removed. SLNs were observed in the obturator region (81.5%), the external iliac region (10.5%), the internal iliac region (4.8%), and the common iliac region (3.2%). Similar proportions were observed on both pelvic sides. No SLNs were detected in other regions. The SLN locations were symmetrical in 22/31 (71.0%) patients. SLNs were negatives in 120 cases (96.8%), while 2 lymph nodes (1.6%) presented isolated tumor cells, and 2 others (1.6%) presented macrometastases. CONCLUSION: We report anatomical distributions and detection rates for SLNs mapped by retroperitoneal vNOTES. Our results suggest substantial differences in the localization of SLNs compared to those reported for laparoscopic mapping.

Recurrence of locally invasive retroperitoneal dedifferentiated liposarcoma shortly after surgery: A case report and literature review.

RATIONALE: Retroperitoneal dedifferentiated liposarcoma (RPDDL) is an uncommon malignancy, which often remains undetected for many years due to having adequate space in the retroperitoneal cavity and lacking clinical manifestations in the early stage of the disease. Surgical procedure is usually used as the first choice for treatment. However, it is prone to local recurrence after the operation, resulting in an unfavorable prognosis. Our aim is to draw useful lessons from the new case and provide some experience for management of the disease. PATIENT CONCERNS: We describe a 55-year-old male patient who was admitted for a 3-week history of persistent dull ache of the left waist. A large mass of the left upper abdomen was palpated in physical examination. Moreover, the imaging examination revealed that the diameter of the mass was about 21 cm, and some adjacent vital organs were invaded, which brought great challenges to complete surgical resection. DIAGNOSIS: The postoperative pathological results confirmed that the mass was RPDDL with invasion of the surrounding vital structures including pancreas, spleen, left adrenal gland, left kidney, and vasculature with tumor emboli. INTERVENTIONS: Surgical resection of the mass was performed by our multidisciplinary team. The patient received chemotherapy 1 month after surgery. OUTCOMES: The effect of chemotherapy seemed to be unsatisfactory. Local multifocal recurrence of the tumor was considered about 2 months after surgery. Finally, he gave up any treatments and died of the disease. LESSONS: Regular physical examination and ultrasound screening may detect the disease as early as possible, especially for high-risk group aged 60 to 70, which should be popularized. Incomplete resection, vascular invasion, and interruption of postoperative treatment may lead to an unfavorable prognosis. Therefore, we think that patients with the disease may benefit from complete surgical resection and uninterrupted adjuvant therapy.