Intravascular Ultrasound for the Evaluation and Management of Retroperitoneal, Genitourinary Malignancies.

PURPOSE OF REVIEW: Herein we provide a review of intravascular ultrasound (IVUS) and its ability to assist in the evaluation and surgical management of advanced retroperitoneal, genitourinary tumors. RECENT FINDINGS: Advanced retroperitoneal tumors such as advanced renal cell carcinoma, bulky retroperitoneal lymphadenopathy associated with advanced testicular carcinoma, large adrenal tumors, and retroperitoneal sarcomas can invade, compress, or distort vascular anatomy making surgical resection challenging and high risk. Intravascular ultrasonography is commonly used by vascular and cardiothoracic surgery to provide a real time assessment of vascular invasion, compression, and aberrant anatomy to assist with pre-operative and/or intraoperative decision-making. However, the application of this technology to assist with cancer surgery has been limited. The use of intravascular ultrasound prior to radical, extirpative, retroperitoneal surgery involving large vessels can aid in the planning and execution of such challenging operations.

Major vascular resection in retroperitoneal sarcoma surgery.

Major blood vessels may be invaded either by primary sarcomas arising from the vessel wall or by secondary infiltration of a retroperitoneal sarcoma. The involvement of major blood vessels is not considered to be an absolute contraindication for surgical resection. The main issue when evaluating a possible major vascular resection is to balance the possible surgical morbidity with the expected survival benefit. This is strictly related to the tumor's biology and clinical behavior and to the patient's performance status and comorbidities. A multidisciplinary approach in a specialized center is mandatory when approaching a possible oncovascular resection for retroperitoneal sarcoma, given the rarity and the heterogeneity of these tumors.

Factors Associated With Perioperative Complications in the Treatment of Pediatric Retroperitoneal Teratoma.

BACKGROUND: Perioperative complications are common during the surgical treatment of pediatric retroperitoneal teratoma (RPT). Some clinical and radiographic features could be associated with perioperative complications. This study was designed to identify the factors associated with such complications. MATERIALS AND METHODS: We retrospectively analyzed the clinical data of RPT patients who underwent surgical treatment at the Department of Pediatric Surgery of The Affiliated Hospital of Qingdao University between January 2008 and January 2020, including demographics, imaging data, intraoperative findings, perioperative complications, pathological data, and outcomes. RESULTS: A total of 91 patients were included in this study, including 30 boys and 61 girls. Of these, 71 patients (78%) were 1 y old or younger. Thirty-eight patients (41%) had perioperative complications (44 intraoperative and 7 postoperative). Preoperative imaging studies showed that the tumor distorted adjacent arteries, veins, and organs in all patients. More veins and organs were displaced and distorted by the tumor in patients who had perioperative complications. Multivariate analysis showed that the number of organs compressed and distorted by the tumor was significantly related to perioperative complications (odds ratio 1.69, 95% confidence interval 1.19-2.41). CONCLUSIONS: Surgical treatment of RPT is complex and challenging. As majority are benign, a complete excision is usually curative. The number of organs compressed and distorted by the tumor is positively related to perioperative complications.

Multidisciplinary Oncovascular Surgery is Safe and Effective in the Treatment of Intra-abdominal and Retroperitoneal Sarcomas: A Retrospective Single Centre Cohort Study and a Comprehensive Literature Review.

OBJECTIVE: Radical excision of retroperitoneal or intra-abdominal soft tissue sarcomas may necessitate vessel resection and reconstruction. The aim of this study was to assess surgical results of retroperitoneal or intra-abdominal sarcomas involving major blood vessels. METHODS: This was a retrospective single centre cohort study and a comprehensive review of literature. Patients with retroperitoneal or intra-abdominal sarcomas treated by the oncovascular team in Helsinki University Hospital from 2010 to 2018 were reviewed for vascular and oncological outcomes. A comprehensive literature review of vascular reconstructions in patients with retroperitoneal sarcoma was performed. RESULTS: Vascular reconstruction was performed in 17 patients, 11 of whom required arterial reconstructions. Sixteen of the operations were sarcoma resections; the post-operative diagnosis for one patient was thrombosis instead of the presumed recurrent leiomyosarcoma. Early graft thrombosis occurred in two venous and one arterial reconstruction. Late thrombosis was detected in three (18%). The median follow up was 27 (range 0-82) months. Of the patients with sarcoma resections 5 (31%) died of sarcoma and further 4 (25%) developed local recurrence or new distant metastases. The comprehensive review of literature identified 37 articles with 110 patients, 89 of whom had inferior vena cava reconstruction only. Eight arterial reconstructions were described. Late graft thrombosis occurred in 14%. The follow up was 0-181 months, during which 57% remained disease free and 7% died of sarcoma. CONCLUSION: Vascular reconstructions enable radical resection of retroperitoneal and intra-abdominal sarcomas in patients with advanced disease. The complex operations are associated with an acceptable rate of serious peri-operative complications and symptomatic thrombosis of the repaired vessel is rare. However, further studies are needed to assess the performance of the vascular reconstructions in the long term.

Management of a giant retroperitoneal leiomyoma: a case report.

BACKGROUND: Leiomyomas are benign tumors observed mainly in adult women. The retroperitoneum is a rare location for leiomyomas; almost 100 cases have been reported. Because retroperitoneal leiomyomas are paucisymptomatic and the tumor size at diagnosis is relatively large, surgical management is challenging. Regular follow-up is required because recurrence and malignant sarcomatous transformation have been described in a few cases. CASE PRESENTATION: We report a case of a 52-year-old North African woman with a 22-cm retroperitoneal leiomyoma. A preoperative embolization was performed 2 days before surgery. The clinical, therapeutic, and evolutive aspects of this rare entity are discussed. CONCLUSIONS: Despite its benignity, retroperitoneal leiomyoma is a challenging diagnostic, therapeutic, and evolutive condition. Surgeons must consider mainly the tumor's vascularization. Regular follow-up is mandatory because malignant transformation cannot be excluded.

Resectability and Vascular Management of Retroperitoneal Gynecological Malignancies: A Large Single-institution Case-Series.

BACKGROUND/AIM: To report on morbidity and oncological outcomes in a consecutive series of gynecological malignancies involving the vascular district. PATIENTS AND METHODS: We retrospectively evaluated a consecutive series between 1/2015 and 1/2017 with suspicious gynecological malignancies involving the vascular district. Peri-operative data and survival rates were computed. RESULTS: Eight-hundred-four women with gynecological malignancies were admitted for major oncologic surgery during the study period, and among them, 50 cases (6.2%) showed vascular involvement. Twenty-seven and 23 patients were submitted to minor and major vascular procedures, respectively. R0 resection was achieved in 44 patients. There were no perioperative mortalities. Major postoperative complications occurred in 6 patients (12.0%). The 2-year disease free survival (DFS) was 67% if R0 resection was achieved. In patients with positive pathological margins (n=2), the 2-year DFS was 33%. CONCLUSION: Vascular procedures can be safely performed with a proper pre-operative planning and may not be an impediment to major gynecological oncological surgery.

Radiological features of primitive neuroectodermal tumors in intra-abdominal and retroperitoneal regions: A series of 18 cases.

OBJECTIVES: To characterize the imaging and clinicopathological features of primitive neuroectodermal tumors (PNETs) arising in intra-abdominal and retroperitoneal regions. METHODS: Eighteen patients with histopathologically proven intra-abdominal and retroperitoneal PNET were enrolled; computed tomography was performed for all cases, and magnetic resonance imaging was performed for a single case. Typical computed tomography and magnetic resonance imaging findings, including morphology, texture and enhancement features, as well as clinicopathological characteristics and prognosis data were retrospectively analyzed. RESULTS: Of eighteen PNET patients, fifteen were male and three were female, with a median age of 36 years (range, 2-65 years). The onset of symptoms was most often nonspecific and insidious. The mean tumor diameter was 7.2 cm (range, 3.0-12.1 cm), with necrosis in fifteen cases, cystic changes in eight, partition structure in five, calcification in five, hemorrhage in two, and mural nodules in one. Contrast enhanced computed tomography showed multiple tiny feeding arteries within the masses in six cases, resulting in a crab-like appearance, and mild ring enhancement pattern in five cases. Eleven cases showed surrounding invasion and metastasis. Of the eighteen PNET cases, nine cases showed smooth, well-defined margins, and nine cases had irregular, ill-defined margins. A median survival was 10.0±1.6 months. However, chemotherapy had efficacy on patients even those with advanced disease. CONCLUSIONS: Primary intra-abdominal and retroperitoneal PNETs are rare, and imaging features documented here may help the diagnosis of this severe disease. Notably, two signs present in retroperitoneal PNET tumors, including a mild ring enhancement pattern and a crab-like appearance of the tiny feeding arteries, may have the potential to help us improve the ability to make a relatively reliable diagnosis.

[A Case of Retroperitoneal Liposarcoma].

A 52-year-old man visited a local hospital complaining of abdominal distension. Enhanced computed tomography scan revealed a giant retroperitoneal tumor surrounding the left internal iliac artery and left kidney. We performed en bloc tumor resection with left internal iliac artery resection. The tumor was 35 cm in size and weighed 6,860 g. The histological diagnosis was a dedifferentiated liposarcoma. After surgery, the patient experienced left lower limb paralysis. Clinical examination and neurological findings suggested a lumbosacral problem. After 6 months, the patient's lower limb paralysis had not improved. It is important to note that ischemic neuropathy may be related to internal iliac artery resection.

[Complex pelvic and sarcoma surgery with vascular replacement]. / Komplexe Becken- und Sarkomchirurgie mit Gefäßersatz.

Due to optimization of surgical techniques in surgical oncology and vascular surgery, the most modern approaches of anesthesia and intensive care medicine and effective multimodal therapeutic strategies, locally advanced malignant tumors are resected more frequently with a potentially curative intent. In the case of extensive tumors with infiltration of vital vascular structures or of structures which are crucial for extremity preservation, the necessary surgical procedure for complete tumor removal poses a major challenge for the surgeon and incorporates a high risk of perioperative morbidity for the patient. The decision to attempt tumor resection should therefore always be based on a concept considering all aspects of the malignant disease. The treating team should be highly experienced in this complex field of surgery, not only with respect to the surgical approach but also regarding the management of postoperative complications. In this article relevant aspects of decision making, surgical technique and postoperative outcome for malignant tumors involving vascular structures of the retroperitoneum and pelvis are presented.

Difference in left renal vein pressure: an indicator for free of reconstruction after ligation in retroperitoneal tumor patients.

We hypothesized that the left renal vein pressure difference (ΔP) before and after the ligation can serve as an objective indicator for free of reconstruction after resection of a retroperitoneal tumor with renal segment of inferior vena cava and right kidney. After established a model of left renal vein compression, 45 miniature pigs were operated on experimental procedures including renal segment of inferior vena cava resection, right nephrectomy, and left renal vein ligation. The ΔPs of left renal vein before and after the ligation were measured. Safe ΔP variation without causing acute kidney injury was calculated using regression analysis. In human the safety range of ΔP before and after ligation of the left renal vein was calculated by diuretic response test. The safety range of ΔP in animals or human was 0-11.9 or 0-17.5 cm H2O, respectively. The renal function changed dramatically (p < 0.01), characterized by a significant increase in the rate of acute kidney injury when the ΔP was beyond the upper limit of the safety range. In conclusion, ΔP can predict free of reconstruction after resection of a retroperitoneal tumor with the renal segment of the inferior vena cava and the right kidney.

Decreased vascularization of retroperitoneal kaposiform hemangioendothelioma induced by treatment with sirolimus explains relief of symptoms.

Kaposiform hemangioendothelioma (KHE) is a vascular tumor with poor prognosis. We present a child with progressive disability, extreme pain, and autonomic dysfunction due to a retroperitoneal KHE where radiologic characteristics were essential for diagnosis and monitoring of response to therapy. He received sirolimus, and the symptomatology resolved completely. Repeat MRIs revealed fast marked decrease in vascularity of the tumor, although the volume was not significantly affected. We suggest that the sirolimus-induced tumor de-vascularization may explain the clinical and coagulopathy improvement.

Luteinizing hormone, sex steroids and extracorporeal circulation - a promising link to treat retroperitoneal sarcomas. A reconsideration of cancer treatment.

Retroperitoneal sarcomas are rare and aggressive tumors with a negative prognosis as there is currently no satisfactory treatment for them. The only proven factor that can significantly increase the otherwise poor survival of sarcoma patients is the radically of resection. However, the completeness of resection is hindered by the hypervascularized nature of sarcomas and the frequent involvement of major blood vessels. In this context, we propose to operate on retroperitoneal sarcomas only with the use of extracorporeal circulation, applying vascular clamps above and below the tumor, even with short periods of hypothermic circulatory arrest in complex cases. This technique would allow the surgeon to achieve complete tumor resections, approach large blood vessels easier and perform sofisticated vascular reconstructions with no fear of hemorrhage which is fundamental to achieve a bloodless surgical field. Also, we speculate on the etiology of retroperitoneal sarcomas that appear mostly during the period of menopause/andropause. Although both estrogens and androgens have been incriminated in inducing various cancer types, including sarcomas, an endogenous estradiol cathabolyte has been shown to have anti-tumor effects. Considering that during menopause/andropause sex steroid levels actually decrease, our second working hypothesis is that the increasing follicle-stimulating hormone (FSH) and especially luteinizing hormone (LH) levels, together with the relative estrogen/androgen imbalance, may be the triggering cause. Also, a certain level of estrogens (Methoxyestradiol) may be essential in limiting tumor development and dedifferentiation. Given that extragonadal sarcomas appear to behave as endocrine tumors, a targeted hormonal therapy, together with controlled radical resections in complex cases of tumor vascular involvement, would certainly provide a strong link to both prevention and treatment of retroperitoneal sarcomas and even of cancer in general.

Uterine adenosarcoma metastasizing to the retroperitoneum. The impact of vascular involvement.

RATIONALE: There is little knowledge regarding mullerian adenosarcoma and its metastasizing pattern. AIM: Our objective was to evaluate the impact on the prognostic of the patient brought by tumor metastasizing to the retroperitoneum, to analyze the particularities of the treatment in such cases and to bring a significant change in the early therapeutic attitude to mullerian adenosarcomas. METHODS AND RESULTS: We present a first case report of a hypervascularized retroperitoneal metastasis from an initial low-grade uterine adenosarcoma. The presence of such a metastasis brought the worst prognostic factor to the patient. CONCLUSIONS: We consider that in front of a macroscopic polypoid mass there should be an active change in the diagnosis and in the therapeutic attitude. The frequent confusion between similar histopathological entities with different aggressiveness states and specific treatment responses, the poor outcome at advanced tumor stages, frequently in young patients, should trigger a universal remodeling in approaching these tumors.

Retroperitoneal vascular surgery for the treatment of giant growing teratoma syndrome.

OBJECTIVE: To evaluate whether an aggressive surgical policy, which included vascular surgery with standard retroperitoneal lymph node dissection (RPLND), would be justified for managing bulky retroperitoneal growing teratoma syndrome (GTS). METHODS: Data were collected retrospectively from a series of 12 patients who, from 1992 to 2010, underwent radical RPLND for bulky GTS (retroperitoneal mass≥10 cm in diameter). For complete resection, vascular procedures and nephrectomy were performed. RESULTS: Median tumor diameter was 100 mm before and 140 mm (range 100-300) after chemotherapy. Two patients underwent iterative RPLND. In addition to RPLND, patients underwent aortic section with aortic anastomosis (n=6), inferior vena cava resection (n=3), both the latter and the former (n=1), and aortic graft with left nephrectomy (n=2). There were no operative deaths; 3 patients had complications (25%), but none were related to extended procedures. The median hospital stay was 15 days. Median follow up was 59 months (range 10-162). One patient died of metastatic cutaneous melanoma 112 months after RPLND, 10 patients survived and are disease-free, and one patient had a para-aortic recurrence. CONCLUSION: A 100% complete resection rate, long-term survival, no mortality, and acceptable morbidity were achieved when vascular surgery and left nephrectomy were combined with standard RPLND for bulky GTS.

Complete and safe resection of challenging retroperitoneal tumors: anticipation of multi-organ and major vascular resection and use of adjunct procedures.

BACKGROUND: Retroperitoneal tumors are often massive and can involve adjacent organs and/or vital structures, making them difficult to resect. Completeness of resection is within the surgeon's control and critical for long-term survival, particularly for malignant disease. Few studies directly address strategies for complete and safe resection of challenging retroperitoneal tumors. METHODS: Fifty-six patients representing 63 cases of primary or recurrent retroperitoneal tumor resection between 2004-2009 were identified and a retrospective chart review was performed. Rates of complete resection, use of adjunct procedures, and perioperative complications were recorded. RESULTS: In 95% of cases, complete resection was achieved. Fifty-eight percent of these cases required en bloc multi-organ resection, and 8% required major vascular resection. Complete resection rates were higher for primary versus recurrent disease. Adjunct procedures (ureteral stents, femoral nerve monitoring, posterior laminotomy, etc.) were used in 54% of cases. Major postoperative complications occurred in 16% of cases, and one patient died (2% mortality). CONCLUSIONS: Complete resection of challenging retroperitoneal tumors is feasible and can be done safely with important pre- and intraoperative considerations in mind.

Targeting multiple angiogenic pathways for the treatment of neuroblastoma.

PURPOSE: Resistance to angiogenesis inhibition can occur through the upregulation of alternative mediators of neovascularization. We used a combination of angiogenesis inhibitors with different mechanisms of action, interferon-beta (IFN-beta) and rapamycin, to target multiple angiogenic pathways to treat neuroblastoma xenografts. METHODS: Subcutaneous and retroperitoneal neuroblastoma xenografts (NB-1691 and SK-N-AS) were used. Continuous delivery of IFN-beta was achieved with adeno-associated virus vector-mediated, liver-targeted gene transfer. Rapamycin was delivered intraperitoneally (5 mg/kg per day). After 2 weeks of treatment, tumor size was measured, and tumor vasculature was evaluated with intravital microscopy and immunohistochemistry. RESULTS: Rapamycin and IFN-beta, alone and in combination, had little effect on tumor cell viability in vitro. In vivo, combination therapy led to fewer intratumoral vessels (69% of control), and the remaining vessels had an altered phenotype, being covered with significantly more pericytes (13x control). Final tumor size was significantly less than controls in all tumor models, with combination therapy having a greater antitumor effect than either monotherapy. CONCLUSION: The combination of IFN-beta and rapamycin altered the vasculature of neuroblastoma xenografts and resulted in significant tumor inhibition. The use of combinations of antiangiogenic agents should be further evaluated for the treatment of neuroblastoma and other solid tumors.

[Clinical manifestation and multiphasic spiral CT scanning features of abdominal pheochromocytoma: report of 70 cases].

OBJECTIVE: The purpose of this study was to assess the imaging characteristics of abdominal pheochromocytoma in multiphasic spiral CT scanning, and to determine whether these image characteristics can aid in differentiating pheochromocytoma from other types of tumors or not. METHODS: The image data of dynamic enhanced CT of 79 pathologically confirmed pheochromocytomas in 70 patients were retrospectively reviewed. RESULTS: Among the 70 patients, there were 41 patients with endocrine symptoms related to pheochromocytoma, 15 had a latent pheochromocytoma and the remaining 14 cases presented with a non-functioning pheochromocytoma. There were totally 79 tumors in 70 patients, with a single lesion in 63 cases, while multiple lesions in the other 7. Sixty cases had a tumor located in the adrenal gland, while 8 in retroperitoneal space, and 2 cases had both intraadrenal and ectopic lesions simultaneously. Sixty patients had a benign pheochromocytoma, the other 10 had a malignant one or relapse after operation. The average size of the tumor was 5.8 cm (range, 2 approximately 15 cm in the longest diameter). Seventy-seven pheochromocytomas had a well defined boundary except two big ones with a unclear margin, which were finally proven to be malignant. Homogeneous enhancement was found in 6 lesions with a diameter