Renal vein valves: a prevalence, microanatomical and histological study

PURPOSE

In the modern era of robotic renal procedures and diagnostics, an even more detailed anatomical understanding than hitherto is necessary. Valves of the renal veins (RVV) have been underemphasized and have been disputed by some authors, and few textbooks describe them. The current anatomical study was performed to address such shortcomings in the literature.

METHODS

One hundred renal veins were studied in fifty adult formalin-fixed cadavers. Renal veins were removed from the abdomen after sectioning them flush with their entrance to the renal hilum. The inferior vena cava was then incised longitudinally and opened, and RVV were examined grossly and histologically. A classification scheme was developed and applied to our findings.

RESULTS

Nineteen RVVs were observed in the fifty cadavers (38%). Four (8%) valves were found on right sides and fifteen (30%) on left sides. The valves were seen as cord/band-like, folds, and single and double leaflets. Histologically, they were all extensions of the tunica intima.

CONCLUSION

On the basis of our study, RVV are not uncommon. They were more common on left sides, and on both sides, they were found within approximately one centimeter of the junction of the inferior vena cava and renal vein. Although the function of such valves cannot be inferred from this anatomical study, the structures of the Single leaflet valve (TS2) and Double leaflet valve (TS3) valves suggest they could prevent venous reflux from the IVC into the kidney.

A cadaveric anatomical study of the adrenals: vascular relationship

The adrenal gland is a retroperitoneal organ with intimate relationships with neighboring organs but also with the large retroperitoneal vessels. Our aim was to study the vascular relationships of the adrenal gland with the large abdominal vessels. Our work is an anatomical dissection of 80 fresh cadaveric adrenals. The subjects didn't have a history of retroperitoneal surgery. Dissection conditions were similar to those in the living. All measurements were made in situ. On the right side, the average distance between the adrenal gland and the renal vein (DR) was 13 mm (0-20). In one case, the adrenal gland laid directly on the right renal vein (DR = 0). The average length L, over which the right adrenal gland entered behind the inferior vena cava (IVC), was 8 mm (0-12). In 4 cases, the right adrenal was lateral to the IVC and in 6 cases the length L exceeded 10 mm. On the left side, the mean distance DL, separating the adrenal gland from the left renal vein was 8 mm with extremes ranging from 0 mm to 18 mm. In eleven cases, the adrenal gland laid directly on the left renal vein. The right adrenal gland has a close relationship with the IVC and is often located behind it. This close relationship helps to explain the increased incidence of IVC lesions during surgery. The left adrenal gland has an intimate relationship with the left renal vein and often lies on top of it. This explains the risk of injury to the left renal pedicle during left adrenal surgery.

Risk factors of worsening kidney function and mortality in patients with renal vein thrombosis: a retrospective study

BACKGROUND

The outcome of renal vein thrombosis, in particular as for the long-term impact on kidney function, is not fully known. We aimed to study the natural course and outcomes of patients with renal vein thrombosis, in a large, single-center cohort.

METHODS

A single-center retrospective cohort study including patients who were diagnosed with renal vein thrombosis between January 2006 and September 2021 was analyzed. The main outcomes analyzed were worsening kidney function, defined as a decrease in eGFR of at least 40% from baseline, and all-cause mortality.

RESULTS

Eighty-seven patients were included, 56.3% were female, median age was 57 years. Malignancy was the most common cause of renal vein thrombosis (60.9%), followed by post-surgery and trauma (16.1%) and nephrotic syndrome (12.6%). At initial presentation, 65.5% of the patients were asymptomatic; the main signs and symptoms were gross hematuria (20.7%), flank pain (18.4%), and flank tenderness (9.2%). During follow-up, 18 (21.4%) patients experienced worsening kidney function and 57 (65.5%) died. Multivariable analyses showed that the risk of worsening kidney function was higher in patients with nephrotic syndrome (hazard ratio [HR] 18.41; 95% confidence interval [CI], 1.57-216.04), body weight ≥ 60 kg (HR 4.82; 95% CI 1.43-16.32), and malignancy (HR 9.10; 95% CI 1.05-78.63). Symptomatic acute renal vein thrombosis was associated with a lower risk of worsening kidney function compared to asymptomatic or symptomatic chronic renal vein thrombosis (HR 0.12; 95% CI 0.01-0.96). Malignancy (HR 5.45; 95% CI 2.58-11.54), age ≥ 75 years (HR 3.44; 95% CI 1.49-7.93), and serum albumin < 3.0 g/dL (HR 2.88; 95% CI 1.65-5.05) were associated with an increased mortality risk.

CONCLUSION

Renal vein thrombosis is associated with a high rate of worsening kidney function and mortality. It is crucial to promptly identify patients at high risk and initiate early treatment to prevent negative outcomes.

Role of Renal Venous Oxygen Pressure for Renal Function Monitoring After Related Living-Donor Kidney Transplantation: Cohort Study

BACKGROUND

Monitoring of renal function after kidney transplantation (KT) is performed by measuring serum creatinine (SCr), urine volumes (UV), and glomerular filtration rate (GFR). Other methods based on oxygen metabolism, such as the renal venous oxygen pressure (PrvO2), may be useful. The aim of this study was to explore the correlation between PrvO2 and SCr, UV, and GFR 5 days after KT (SCr5, UV5, and GFR5, respectively).

METHODS

We conducted a prospective cohort study in adults scheduled for living donor KT. A venous blood sample was taken from the renal vein after declamping the renal artery, and blood gas determinations were made. Correlation analyses between PrvO2 and SCr5, UV5, and GFR5 were done by calculating Spearman's correlation coefficient with generalized linear models (GLM). A Spearman's correlation analysis was performed between the percentage decrease in SCr (%ΔSCr) and PrvO2. A GLM was also performed to determine the association of PrvO2 with slow graft function (SGF).

RESULTS

The study included 42 patients, of whom 67% were men. The median age was 31 years (IQR, 27-43.5). PrvO2 was negatively correlated with SCr5 (ρ = -0.53, P = .003), and positively correlated with GFR5 (ρ = 0.49, P = .001) and %ΔSCr (ρ = 0.47, P = .002). A higher PrvO2 was associated with an increase in GFR in univariable (β = 1.24, 95% CI, 0.56-1.93, P = .001) and multivariable (β = 1.24, 95% CI, 0.53-1.94, P = .001) analyses. No association was found between PrvO2 and SGF.

CONCLUSION

PrvO2 could be used to monitor renal function in the first 5 days after related living-donor KT, given its good correlation with SCr and GFR.

Absorbable Clips Applied in Thoracoscopic Anatomical Lung Resection in Younger Children

OBJECTIVES

This study aims to evaluate the feasibility and safety of a 5-mm absorbable clips applied in thoracoscopic anatomical lung resection in younger children.

METHODS

Demographic data and intra- and postoperative parameters of the two groups (Abs-o-lock® group and Hem-o-lok® group) were reviewed. In the Abs-o-lock® group, 5-mm absorbable clips were used in thoracoscopic anatomical lung resection on all patients from January 2020 to March 2021. In the Hem-o-lok® group, 5-mm Hem-o-lok® clips were used from January to December 2019. The primary outcomes were the one-time success rate of ligation, major bleeding rate, intraoperative dislodgement rate and operative time, which were compared between the two groups.

RESULTS

There were 224 patients involved in this study, of whom 103 were in the Abs-o-lock® group and 121 were in the Hem-o-lok® group. The one-time success rate of ligation was 96.5% in the Abs-o-lock® group and 98.9% in the Hem-o-lok® group (p < 0.05). No major bleeding occurred in either group. The intraoperative dislodgement rate did not significantly differ between the two groups (p = 1.0). The operative time consumed in the Abs-o-lock® group was much longer than that in the Hem-o-lok® group for subgroups of resection of extralobar sequestration (p < 0.05), lobectomy (p < 0.05) and segmentectomy (p < 0.05).

CONCLUSIONS

Compared to Hem-o-lok® clips, it is feasible and safe to apply 5-mm absorbable clips for vessel sealing during thoracoscopic anatomical lung resection in younger children.

Pharmarcomechanical thrombectomy combined with transluminal balloon angioplasty for treating transplant renal vein thrombosis

Renal vein thrombosis (RVT) is a rare vascular complication that occurs after renal transplantation and usually results in irreversible kidney damage and graft loss. We report the case of a patient who underwent right iliac fossa allogeneic kidney transplantation and developed RVT combined with ipsilateral thrombosis from the popliteal to the femoral veins, with extension to the common iliac veins, 4 months after transplantation. Under unfractionated heparin anticoagulation, an Aegisy (Life Tech Scientific Co., Ltd., Shenzhen, China) vena cava filter was placed to prevent pulmonary embolism. Percutaneous mechanical thrombectomy combined with balloon angioplasty was performed to aspirate the thrombus and successfully dilate the narrow venous lumen. The patient's renal function was restored postoperatively. Ultrasonography showed the allograft and ipsilateral lower extremity deep veins to be fluent and patent. To conclude, in patients with RVT after renal transplantation, percutaneous mechanical thrombectomy in conjunction with balloon angioplasty can be performed with desirable outcomes and no severe adverse effects. This method reduces the risk of bleeding from exposure to systemic intravenous thrombolysis and avoids surgery-associated trauma.

Surgical management strategy for leiomyosarcoma of Zone I-II inferior vena cava: A case series

OBJECTIVES

Leiomyosarcoma of inferior vena cava (IVC) is a rare clinical entity with severe vascular involvement. Surgical management of leiomyosarcoma is still challenging.

METHODS

This a retrospective study of consecutive patients referred to our hospital from January 2017 to June 2019. Depending on the anatomical site of affected IVC, leiomyosarcomas were categorized into zone I-II. The clinical data including baseline information, surgical parameters, peri-operative management, short- and mid-term outcomes were observed.

RESULTS

Four patients with leiomyosarcoma of zone I-III underwent radical resection without intraoperative mortality. Prosthetic grafts were interpositioned in all patients to instruct vena cava. Renal vein reconstruction was perfumed in two patients due to involvement to renal veins. Median blood loss was 450 mL (200-600 mL), median operative time was 215 minutes (150-240 minutes). No Clavien-Dindo IIIa or higher complication was observed. No organ dysfunction and recurrence were observed with median follow-up of 25.5 months.

CONCLUSIONS

Curative resection of zone I-II leiomyosarcoma is associated with longer survival in selected cases, en-bloc resection with complex vascular reconstruction could be considered.

Endovascular management of nutcracker syndrome in an adolescent patient population

BACKGROUND

Nutcracker syndrome is defined as left renal vein compression with concomitant clinical symptoms that include flank pain and hematuria. Historically, pediatric and adolescent patients with mild symptoms of nutcracker syndrome were simply observed while those with more severe symptoms underwent left renal vein transposition. Endovascular stenting of the left renal vein is a potentially efficacious and less invasive alternative for managing nutcracker syndrome in adolescents.

OBJECTIVE

The purpose of this study was to investigate the technical feasibility, efficacy and safety of left renal vein stenting in adolescents with nutcracker syndrome.

MATERIALS AND METHODS

We conducted a retrospective review of electronic medical records and imaging archives to identify adolescents undergoing endovascular stenting for nutcracker syndrome. We reviewed patient demographics including age, gender, presenting symptoms and diagnostic imaging findings. We compared pre- and post-stent deployment intravascular ultrasound (IVUS) and venography and evaluated patient symptoms in clinic up to 6 months following stent placement.

RESULTS

Ten patients (average age 16 years, range 12-20 years) underwent 13 procedures. Initial symptoms included pain (n=10) and gross hematuria (n=5). Diagnostic imaging studies included CT abdomen pelvis (n=8), retroperitoneal US (n=6), MRI abdomen/pelvis (n=4), scrotal US (n=2), pelvic US (n=1) and renal Doppler US (n=2). Venography and IVUS demonstrated venous collaterals, proximal blanching at the left-renal-vein-IVC junction, pre-stenotic dilation and intraluminal compression. Most patients (n=9) experienced symptomatic resolution; however, three patients required reintervention to achieve asymptomatic status. No periprocedural complications occurred.

CONCLUSION

In this carefully selected adolescent cohort, left renal vein stenting for nutcracker syndrome was often technically feasible, safe and effective in symptom management.

Impact of spontaneous splenorenal shunt on liver volume and long-term survival of liver cirrhosis

BACKGROUND AND AIM

Spontaneous splenorenal shunt (SSRS) is one of the manifestations of portal hypertension in liver cirrhosis. However, the impact of SSRS on long-term survival of cirrhotic patients remains unclear. We hypothesize that SSRS may worsen liver dysfunction and deteriorate prognosis in liver cirrhosis by decreasing hepatic perfusion.

METHODS

Patients with liver cirrhosis who were admitted to our department between December 2014 and August 2019 and underwent contrast-enhanced computed tomography or magnetic resonance imaging scans were prospectively collected. The maximum diameters of SSRS and portal vein system vessels were retrospectively measured. Liver-to-abdominal area ratio, Child-Pugh, and model for end-stage liver disease scores were calculated.

RESULTS

Overall, 122 cirrhotic patients were included. The prevalence of SSRS was 30.3% (37/122). Median diameter of SSRS was 13.5 mm. Patients with SSRS had significantly thinner diameters of right portal vein (9 mm vs 11.2 mm, P = 0.001) and main portal vein (15.3 mm vs 16.8 mm, P = 0.017) than those without SSRS. Patients with SSRS had significantly lower liver-to-abdominal area ratio score (25.39 vs 31.58, P < 0.001) and higher Child-Pugh (7 vs 6, P = 0.046) and model for end-stage liver disease (12.17 vs 9.79, P < 0.006) scores than those without SSRS. Patients with SSRS had a significantly lower cumulative survival rate than those without SSRS (P = 0.014). Cox regression analysis also showed that SSRS was a risk factor of death of cirrhotic patients (hazard ratio = 4.161, 95% confidence interval = 1.215-14.255, P = 0.023).

CONCLUSIONS

Spontaneous splenorenal shunt may narrow portal vein diameter and shrink liver volume, thereby worsening liver function and increasing mortality in liver cirrhosis.

The effect of renal artery-only or renal artery-vein clamping during partial nephrectomy on short and long-term functional results: Is clamping technique important?

PURPOSE

To evaluate the effect of artery-only (AO) and artery-vein (AV) clamping during partial nephrectomy (PN) on short- and long-term renal function outcome.

METHODS

Medical records of 154 patients in the AO group and 192 patients in the AV group who underwent open and minimally invasive (laparoscopic/robotic) PN between January 2011 and January 2018 were retrospectively assessed. Preoperative patient and tumor-specific characteristics in addition to perioperative factors and renal function outcomes were compared. The change in the estimated glomerular filtration rate (eGFR) from postoperative 1-3 days, 12 and 24 months after surgery was calculated. Acute kidney injury (AKI) was defined a as a > 25% reduction in eGFR.

RESULTS

There were no statistically significant differences between the clamping techniques in terms of postoperative 1-3 days, 12 and 24 months eGFR change percentage and risk of progression to chronic kidney disease (CKD). No significant difference in short- and long-term renal functions was found between the minimally invasive or open AO and AV clamping subgroups at any time point. In multivariate analysis, the R.E.N.A.L score (AO group p = 0.026, AV group p < 0.001) and preoperative eGFR (AO group p < 0.001, AV group p = 0.010) were strong predictors of the acute kidney injury in both groups. Older age (AO group p = 0.045, AV group p = 0.010) and preoperative eGFR (AO group p = 0.008, AV group p = 0.002) were significantly associated with CKD progression at 2-year follow-up in both groups.

CONCLUSION

AV clamping does not adversely affect postoperative renal function compared to AO clamping. Preoperative patient- and tumor-related factors are more important for renal function regardless of the clamping technique.

A rare case report of renal vein pseudoaneurysm after blunt trauma

RATIONALE

Renal vein pseudoaneurysm after blunt trauma is an extremely rare clinical disease. Different interventions, such as conservative, surgical, and endovascular treatments, can be considered. However, previous studies have not described the optimal treatment strategies for this condition. Furthermore, there is a significant lack of prior case reports and of standardized treatment guidelines for trauma-induced renal vein pseudoaneurysm patients who previously maintained antithrombotic agent.

PATIENT CONCERNS

A 23-year-old female patient visited the emergency department after sustaining blunt injury caused by falling. The patient was diagnosed with multiple limb and rib fractures. A right renal vein pseudoaneurysm was found on abdominal computed tomography scan. Initially, there was no other organ damage, and the patient was hemodynamically stable. Thus, nonsurgical, conservative management was considered. However, the patient's hematocrit and hemoglobin levels decreased, and there was no hemodynamic improvement. The patient required lifelong treatment with aspirin because she previously underwent Fontan surgery, and orthopedic surgery for multiple fractures was planned. Thus, considering these factors, the treatment method was changed from conservative management to endovascular stent insertion.

DIAGNOSES

Abdominal computed tomography and renal venography revealed a right renal vein pseudoaneurysm.

INTERVENTIONS

On the basis of the abdominal computed tomography scan and renal venography findings, the endovascular stent graft was inserted across the pseudoaneurysm area.

OUTCOMES

Upon placement of the endovascular stent, hemoglobin and hematocrit levels gradually returned to normal. The patient's vital signs and general condition had improved. The patient recovered without any complications and was discharged 29 days after hospitalization.

LESSONS

Some patients with traumatic renal vein pseudoaneurysm do not experience hemodynamic improvement despite conservative treatment. Hence, endovascular procedure may be considered for these patients, particularly those who require antithrombotic treatment for a previous disease.

A Case of Posterior Nutcracker Syndrome Revealed in the Aerospace Environment

BACKGROUND: Nutcracker syndrome is caused by a rare anatomic variant where the left renal vein is trapped between the aorta and the superior mesenteric artery. Posterior nutcracker syndrome is an even rarer entity, characterized by the retro-aortic positioning of the renal vein, causing compression between the aorta and spinal vertebrae. Symptoms include microscopic or frank hematuria, flank pain, varicocele, pelvic congestion syndrome, and abdominal pain. A search of the literature did not reveal prior cases of nutcracker syndrome that became symptomatic and diagnosed secondary to the unique stressors of high gravitational force (G force) in the aviation environment.CASE REPORT: A 25-yr-old man training as an F-16 flight test engineer presented with left scrotal/testicular pain, varicocele, and intermittent gross hematuria. After an extensive workup, he was diagnosed with posterior nutcracker syndrome and underwent a left varicocele ligation with spermatic cord denervation. He was eventually able to be returned to flying duties with limitation to non-high performance aircraft.DISCUSSION: This case is particularly unique as its diagnosis was dependent on exposure to high G force conditions that may have otherwise remained asymptomatic without this environmental stressor. Education on the diagnosis of nutcracker syndrome as a differential in the setting of hematuria and pain is an important lesson learned. This case also illustrates the necessity of considering the effects of the stressful environment of high G force on even overall healthy individuals. Fortunately, due to the collaboration of medical-surgical expertise and familiarity with the requirements for operational readiness, this patient was able to resume his aviation career, albeit in a different capacity compatible with his condition.Chung CY, Lytle ME, Clemente Fuentes RW. A case of posterior nutcracker syndrome revealed in the aerospace environment. Aerosp Med Hum Perform. 2021; 92(1):5456.

Co-occurrence of compression syndromes: celiac axis stenosis, superior mesenteric artery and nutcracker syndrome

Moreno Márquez et al. report an association between arcuate ligament syndrome (ALS) and the "nutcracker" phenomenon (compression of the left renal vein). The case illustrates the association between several syndromes, which all involve compression of vascular or gastrointestinal structures: arcuate ligament syndrome, superior mesenteric artery syndrome (SMAS) or Wilkie's syndrome, the "nutcracker" syndrome and May-Thurner syndrome (compression of the left iliac vein).

Retrograde venous bullet embolism into renal vein

The unpredictable nature and behaviour of bullet emboli can pose unique diagnostic and management challenges, related to the absence of exit wounds or variable trajectories. However, embolisation into the vascular system is an extremely unusual occurrence, with fewer than 200 such cases described since 1900. Given the relative paucity of such literature reports, it is not surprising that guidelines for the optimal management of some of these emboli are neither clear cut, nor universally accepted. We report the second case of retrograde venous bullet embolism to the right renal vein following a gunshot injury to the right chest and the surgical solution.

Abdominal Aortic Aneurysm Complicated With Aorto-Left Retroaortic Renal Vein Fistula

We present the case of a male with a fistula from an infrarenal aortic aneurysm to the left renal vein resolved with an endovascular prosthesis. Few cases have been reported in the literature.

Implications of extraperitoneal paraaortic lymphadenectomy to the left renal vein in locally advanced cervical cancer. A Spanish multicenter study

OBJECTIVE

Paraaortic lymph node involvement is an important prognostic factor in locally advanced cervical cancer (LACC), but the anatomic limit of aortic lymphadenectomy is controversial. We assessed the impact of extraperitoneal paraaortic lymphadenectomy up to the left renal vein in patients with LACC undergoing pretherapeutic staging.

METHODS

A retrospective, multicenter study of patients with LACC stages FIGO 2009 IB2 and IIA2-IVA treated in 10 Spanish reference hospitals in gynecological oncology between 2000 and 2016. Sites of metastatic paraaortic lymph nodes above or below the inferior mesenteric artery were evaluated. Procedural-related intraoperative and early and late complications were assessed.

RESULTS

We included 634 patients undergoing paraaortic lymphadenectomy, in 616 (97.2%) of which the left renal vein was the upper limit of dissection (laparoscopy 592, robotic-assisted 24). The median surgical time was 150 min (interquartile range (IQR) 120-180), blood loss was 50 mL (range 20-80), and the length of stay was 2 days (range 2-3). Metastatic paraaortic involvement was found in 114 patients (18.5%), with infrarenal metastases in 73 (64%) of them. There were 11 patients (9.6%) with infrarenal metastases only, whereas in the remaining 62 (54.4%) patients concomitant infrarenal and inframesenteric metastases were observed. Intraoperative, early, and late postoperative complications occurred in 3.6%, 7.0%, and 4.5% of patients, respectively.

CONCLUSIONS

In this study of patients with LACC undergoing surgical staging, paraaortic lymphadenectomy up to the left renal vein detected skip or isolated infrarenal metastasis in 9.6% of patients, with an acceptable surgical morbidity.

Use of Iliac Allograft from Cadaveric Donor as a Rescue Technique in Living Donor Kidney Transplant: Two Case Reports

BACKGROUND

A short right renal vein (RRV) remains a challenge for renal transplant surgery, especially in the living donor. Different techniques exist to obtain an RRV with a suitable length in cadaveric donor; however, in living donors the options are limited.

MATERIAL AND METHODS

We present 2 living kidney transplants in which we obtained a very short RRV, making the implantation very difficult. We describe our technique to overcome this problem by using cadaveric iliac vessels retrieved from previous cadaveric donations and preserved at 4°C in histidine-tryptophan-ketoglutarate (HTK) solution, without intraoperative or postoperative complications. We complied with the Helsinki Congress and the Istanbul Declaration regarding the donor source.

RESULTS

In both cases, kidney grafts had optimal primary function, with good creatinine clearance after transplant and good patency of vascular anastomosis by Doppler ultrasounds.

CONCLUSIONS

We believe the use of cadaveric vessel grafts in living donor kidney transplant is a valuable resource as a rescue tool in emergency situations like the ones being presented in this article in order to avoid discarding a kidney graft with damage or short vessels. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Intractable hepatic encephalopathy in cirrhotic patients: mid-term efficacy of balloon-occluded retrograde portosystemic shunt obliteration

PURPOSE

To evaluate the efficacy and intermediate-term outcome of balloon-occluded retrograde transvenous obliteration (BRTO) for the treatment of hepatic encephalopathy (HE) secondary to portosystemic shunt (PSS) in cirrhotic patients.

MATERIALS AND METHODS

Institutional review board (IRB) approval was obtained for this study and hospital records of patients who underwent BRTO, from August 2011 to August 2015, were analyzed. Based on the inclusion and exclusion criteria, 39 patients (age, 54.07 ± 9.1 years (37-67 years); 33 males and 6 females) with cirrhosis and spontaneous PSS were included. Clinical and laboratory parameters and HE grade were evaluated in all patients before and after the procedure.

RESULTS

Forty sessions of BRTO were attempted in 39 patients. Follow-up imaging revealed complete obliteration of the treated PSS in all patients with clinical success in 37 patients (94.9%). The 1-, 2-, 3-, 4-, 5-, 6-, and 7-year HE-free survival rates among responders were 91.7%, 91.7%, 88.8%, 85.5%, 80.8%, 80.8%, and 80.8% respectively and overall survival rates were 89.7%, 82.1%, 76.9%, 74.4%, 74.4%, 64.8%, and 64.8% respectively. Logistic regression highlighted Child-Turcotte-Pugh (CTP) score at 6 months as a positive predictive factor of HE recurrence with a cutoff of ≥ 9. Five patients (12.8%) had fever and leukocytosis and 1 (2.6%) patient developed spontaneous bacterial peritonitis after the procedure.

CONCLUSION

BRTO is an effective treatment for refractory HE in cirrhotics secondary to large PSS with a few possible complications.

KEY POINTS

• BRTO is an effective and safe treatment for refractory HE, arising from PSS in cirrhotic patients. • Patients with preserved liver function show better outcome and CTP score is the most important predictor of relapse during follow-up.

NEPHRON-SPARING SURGERY IN PATIENTS WITH RENAL CELL CARCINOMA EXTENDING TO THE MAIN RENAL VEIN: INTRARENAL AND EXTRARENAL THROMBECTOMY

In most cases RCC with venous extension is an indication for radical nephrectomy. However, in patients with imperative indications for nephron-sparing surgery a kidney resection with thrombectomy in rare situations is possible. We present a surgical technique for nephron-sparing surgery in patients with tumor spreading into the main renal vein. From 2007 to 2019 seven partial nephrectomies with removal of the tumor thrombus from the main renal vein were performed. Absolute imperative indications were recorded in 6 (85.7%) patients (4 with solitary kidney, 2 with bilateral tumors). Dimensions of renal tumor averaged 6.5±2.3 cm. Intravenous part of the tumor penetrated the initial portion of the renal vein in 3 cases, main trunk of the renal vein in 3 cases, and cavarenal portion of the IVC in 1 case. The average length of the tumor thrombus was 24.0±6.9 mm, and the width was 9.3±4.8 mm. Tumor thrombi were classified as intrarenal and extrarenal. In accordance with this principle surgical procedures were divided into partial nephrectomy with intrarenal (3/42.9%) and extrarenal thrombectomy (4/57.1%). Intrarenal thrombectomy was characterized by thrombus removal out of the vein lumen from the side of the kidney resection area, while extrarenal thrombectomy included additional opening the lumen of the main renal vein or inferior vena cava (IVC). In one patient hypothermic perfusion of the kidney in situ was used. In two cases the extracorporeal partial nephrectomy with kidney autotransplantation was performed. Warm ischemia time averaged 14.0 minutes. The time of ischemia during hypothermic perfusion in situ reached 76 minutes, the time of cold ischemia during extracorporeal surgery averaged 68.0 minutes. The volume of blood loss did not exceed an average of 621.4±146.8 ml. Early postoperative complications occurred in 4 (57.1%) cases (bleeding -1, ischemic stroke -1, deterioration of renal failure -2). Postoperative mortality was registered in 1 patient due to bleeding and heart failure. The follow-up period averaged 28.7±18.9 months. Distant metastases occurred in 1 (14.3%) patient after 16 months. Local tumor recurrence in the remnant kidney after nephron-sparing surgery was not detected in any case. Nephron-sparing surgery may be used to treat patients with kidney tumors and neoplastic venous thrombosis. However, this complex surgical approach requires further technical improvement.

[Kidney cancer stage pT3a: Fat invasion versus renal vein invasion.]

OBJECTIVE

We discuss the influence that involvement of fat (perirenal, sinus) and vascular structures (renal vein, segmental veins) have on cancer-specific mortality (CSM) rates in renal cancer.

METHODS

We conducted a retrospective analysis of 140 stage pT3a kidney tumors (114 clear cell, 9 type I papillary, 6 type II papillary, 11 chromophobe) surgically treated between 1997 and 2015. We conducted a cancer-specific survival study (Kaplan Meier) and a univariate and multivariate analysis of the variables: perirenal fat invasion, sinus fat invasion, renal vein invasion, segmental vein invasion and Fuhrman grade.

RESULTS

With a mean follow-up of 79 months, 47 deaths occurred overall (31.7%), 29 of which were due to the kidney tumor (CSM 20%). There were 50 cases of vascular invasion (35.7%), 40 cases with fat only invasion (28.6%) and 50 cases with invasion of both (35.7%). In the survival study, fat invasion had the least impact (17%), and invasion of both (fat and vascular structures) had the worst survival (48% of total mortality). Vascular invasion represents 35% of the mortality rate. In the multivariate study, Fuhrman grade 3-4 (HR 10.7), renal vein invasion (HR 9.2) and concomitant vascular and fat invasion (HR 5.6) are the factors with the greatest impact.

CONCLUSIONS

Tumor fat invasion has a lower impact on the CSM of kidney cancer than vascular invasion.

[Microsurgical bypass for varicocele with nutcracker syndrome]

OBJECTIVE

To investigate the clinical effect and feasibility of internal spermatic vein-inferior epigastric vein (ISV-IEV) bypass surgery in the treatment of varicocele complicated by left renal vein nutcracker syndrome (NCS).

METHODS

We retrospectively analyzed the clinical data about 30 cases of varicocele with left renal vein NCS treated by ISV-IEV bypass surgery in our hospital from June 2014 to February 2017. We reviewed the follow-up data and results of ultrasonography, routine urianlysis and semen routine examination.

RESULTS

All the operations were successfully accomplished and postoperative color Doppler ultrasonography showed that varicocele was cured in all the cases. At 6 months after surgery, sperm concentration and the percentage of grade a+b sperm were significantly improved (［34.47 ± 8.60］ ×10⁶/ml and ［63.54% ± 9.58］ %) as compared with the baseline (［19.90 ± 8.97］ ×10⁶/ml and ［37.93 ± 8.73］ %) (P <0.05). Hematuria was cured in 23 and alleviated in 1 of the 24 cases. Proteinuria disappeared in all the 14 cases, with neither scrotal pain symptoms nor obvious complications.

CONCLUSIONS

ISV-IEV bypass surgery, with its advantages of safety, effectiveness, minimal invasiveness, and simple operation, deserves wide clinical application in the treatment of varicocele with left renal vein NCS.

[Gross Hematuria after kidney biopsy. A case report]

We describe the clinical case of a patient experiencing severe gross hematuria causing clotting in the renal pelvis, after undergoing a kidney biopsy.The ecocolordopper and CT angiography performed did not reveal the cause of hematuria.The kidney arteriography allowed the diagnosis, revealing an arteriovenous fistula responsible for bleeding together with a small false aneurysm in the lower pole of the biopsied kidney. Both lesions were successfully treated with superselective embolization with microcoils. We discuss about the diagnostic and therapeutic approach of these rare post-biopsy complications briefly focusing on the technical aspects and on possible risks that the transcatheter embolotherapy may result.

[Prognostic factors in renal cancer with venous thrombus survival analysis.]

OBJECTIVES

To analyze surgery for renal cancer with venous thrombus at different levels, perioperative complications and prognostic factors associated to overall, cancer-specific and disease-free survival.

MATERIAL AND METHODS

Retrospective analysis of 42 cases of renal cancer with venous thrombus performed between 2005 and 2015. The level reached by the thrombus was established according to the Mayo Clinic classification. Postoperative complications were staged according to Clavien-Dindo classification.

RESULTS

Most frequent in males. Mean age 65.7 years. 16.6% were tumors with level II thrombus. Subcostal approach was performed in 58.9%. Extracorporeal circulation with cardiac arrest and hypothermia was established in 2 patients. Resection of metastatic disease was performed in 3 patients during radical nephrectomy. Reoperation was 2.3% while, perioperative mortality was 4.7%. 30% presented with metastases at diagnosis. Twenty patients progressed at 15.5 months (3-55). Overall survival was 60 months. The cancer-specific mortality was 75%. Disease-free survival was 30% at 55 months.

CONCLUSIONS

Surgical treatment of renal cancer with venous thrombus requires a multidisciplinary management. The surgical technique varies according to the level reached by the venous thrombus. Tumor stage is the most important prognostic factor. Thrombus level influences prognosis, with longer survival for patients with tumor thrombus confined to the renal vein (pT3a) in comparison to tumors with thrombus in the atrium (pT3c).

Catheter-Directed Fibrinolysis of Submassive Pulmonary Embolism After IVC Filter Migration to Renal Veins

A 76-year-old male presented with a submassive pulmonary embolism despite having an inferior vena cava (IVC) filter. Imaging demonstrated pulmonary artery emboli and a deep vein thrombosis in the left common femoral vein. Venography revealed the IVC filter with struts extending into the left and right renal veins. A new IVC filter was deployed below the prior filter. This case demonstrates IVC filter migration complicated by a submassive pulmonary embolism.

Characteristics of patients diagnosed with renal vein thrombosis and glomerulopathy: a case series

BACKGROUND

Few contemporary studies have evaluated the clinical characteristics of patients with biopsy-proven glomerulopathy diagnosed with renal vein thrombosis (RVT).

METHODS

Retrospective case series study within an integrated health system in a 12-year period (January 1, 2000 through December 31, 2011) investigating clinical characteristics of all adult patients who underwent native or transplant kidney biopsy and also had a diagnosis of RVT. Patient characteristics, diagnostic studies, and outcomes were evaluated.

RESULTS

Among 3763 eligible patients, 17 had imaging confirmed RVT. Of these, 15 had membranous nephropathy (idiopathic or secondary to autoimmune disease). Although the biopsy population included primary and secondary glomerular disease patients, all 17 RVT patients had severe nephrotic syndrome and profound hypoalbuminemia with mean (SD) of albumin: 1.5 g/dL (0.66).

CONCLUSION

Clinically significant RVT in patients with glomerulopathy appears to be a rather rare entity, occurring predominantly in patients with severe nephrotic syndrome due to idiopathic membranous nephropathy and membranous nephropathy secondary to autoimmune disease.

Renal vascular thrombosis in the newborn

Neonatal renal vascular thrombosis is rare but has devastating sequelae. The renal vein is more commonly affected than the renal artery. Most neonates with renal vein thrombosis present with at least one of the three cardinal signs, namely, abdominal mass, macroscopic hematuria and thrombocytopenia, while unilateral renal artery thrombosis presents with transient hypertension. Contrast angiography is the gold standard for diagnosis but because of exposure to radiation and contrast agents, Doppler ultrasound scan is widely used instead. Baseline laboratory tests for platelet count, prothrombin time, activated partial thromboplastin time and fibrinogen concentration are essential before therapy is initiated. Maternal blood is tested for lupus anticoagulant and anticardiolipin antibody. Evaluation for prothrombotic disorders is warranted when thrombosis is clinically significant, recurrent or spontaneous. Management should involve a multidisciplinary team that includes neonatologists, radiologists, pediatric hematologists and nephrologists. In addition to supportive therapy, recent guidelines recommend at least prophylactic heparin therapy in the majority of cases to prevent thrombus extension. Thrombolytic therapy is reserved for bilateral thrombosis compromising kidney function. Long-term sequelae, such as kidney atrophy, systemic hypertension and chronic kidney disease, are common, and follow-up by pediatric nephrologists is recommended for monitoring of kidney function, early detection and management of hypertension and chronic kidney disease.

Acute Renal Failure in the Neonate

Acute renal failure (ARF) in a neonate is a serious condition that impacts 8% to 24% of hospitalized neonates. There is a need for prompt evaluation and treatment to avoid additional complications. In this review, a neonate was found to have renal failure associated with renal vein thrombosis. There are varying etiologies of ARF. Causes of ARF are typically divided into three subsets: pre-renal, renal or intrinsic, and post-renal. Treatment of ARF varies based on the cause. Renal vein thrombosis is an interesting cause of renal or intrinsic ARF and can be serious, often leading to a need for dialysis.

[Tea polyphenols reduces the apoptosis of spermatogenic cells in rats with experimental varicocele]

OBJECTIVE

To study the effect of tea polyphenols (TP) on the apoptosis of germ cells in rats with experimental varicocele.

METHODS

Thirty-two adolescent male Wistar rats were randomly and equally divided into groups A (sham-operation), B (high-dose TP), C (low-dose TP), and D (experimental left varicocele). Experimental varicocele was induced by partial ligation of the left renal vein in the latter three groups of rats. The animals in groups A and D were fed with normal saline, while those in B and C with TP at 40 and 10 mg per kg per d, respectively, all for 4 weeks. Then, all the rats were sacrificed and the left testes harvested for determination of the expression of HIF-1, Bcl-2, Bax, CytC, and caspase-3 by immunohistochemistry and measurement of the apoptosis index (AI) of spermatogenic cells.

RESULTS

The expression of Bcl-2 was higher in groups B and C than in D but lower than in A (P < 0.05), and lower in C than in B (P < 0.05). However, the expressions of HIF-1, Bax, CytC, and caspase-3 were lower in groups B and C than in D but higher than in A (P < 0.05), and higher in C than in B (P < 0.05). The AI of spermatogenic cells was the lowest in group A, higher in D than in the other groups but lower in B than in C (P < 0.05).

CONCLUSION

TP can reduce the apoptosis of spermatogenic cells in a dose-dependent manner in varicocele rats.

Renal Vein Thrombosis in a Newborn With Abnormal Factor VIII Level: Clinical Case Report

Renal vein thrombosis (RVT) in neonates is a rare condition of low mortality but significant morbidity due to renal impairment.We report the case of a male term newborn with left RVT and elevated serum factor VIII (FVIII).The main symptoms of the patient and the important clinical findings: prompt diagnosis of RVT was possible because the classic clinical presentation of macroscopic hematuria, thrombocytopenia, and palpable flank mass were present in this newborn infant.The main diagnoses: finally, the reason of RVT was established when the infant was 3 months of age: the increased level of FVIII was confirmed. We discuss the diagnosis, therapy, and outcome of the patient and compare with the literature.Therapeutics interventions: however, despite anticoagulant therapy the left kidney developed areas of scarring and then atrophy.Conclusions and outcomes: Prothrombotic defects should be considered in all patients with perinatal RVT. Elevated factor VIII as a reason of RVT in neonatal period is particularly rare. Given a poor renal outcome in children associated with elevated levels of factor VIII, consideration could be given to more aggressive antithrombotic therapy in such cases.

Observations on the use and limitations of renal vein renins in hypertensive patients

From our consecutive series of renal vein renin studies in 170 patients with kidney disorders and hypertension, we present those cured by surgical correction of a unilateral renal artery stenosis during the period 1973--75. The renin secretion patterns of these patients range between no demonstrable abnormality, even with a stimulating procedure using dihydralazine 7.5 i.v., and massive renin secretion already during basal conditions. Thus, the renin secretion may not be increased even after stimulation in some patients with durable unilateral renovascular hypertension. This fact may be explained by the rise of the systemic blood pressure, eventually maintained by sodium and water retention and accompanied by adaptive changes in the contralateral kidney. The perfusion pressure is thereby kept normal in the affected kidney, eliminating a stimulus for renin secretion. It is likely that many cases of renovascular hypertension pass through an early stage where no involvement of the renin-angiotensin system may be discovered. Of course, these patients will also benefit from surgery. The conclusion is that renin studies for diagnostic purposes should be performed when patients are on treatment and kept normotensive for some time, and that an additional challenge of the perfusion pressure, i.e., by use of dihydralazine, intravenously should be performed.

Plasma renin activity in renal veins of renovascular patients

PRA was simultaneously measured in both renal veins and in a peripheral vein of patients with essential (6) and renovascular (37) hypertension. In renovascular patients suppression or renin secretion from the contralateral kidney was always observed: otherwise in patients with essential hypertension both kidneys contribute to peripheral PRA. The suppression of renin secretion from the ischemic kidney either by nephrectomy or by revascularization, joins with normalization either of peripheral PRA or of blood pressure. This finding points to the role of the renin-angiotensin system in the genesis of human renovascular hypertension.

Renin, renin substrate and angiotensin II concentration in renal venous blood

In 22 hypertensive patients with unilateral renal artery stenosis (RAS) and in 8 patients with unilateral or bilateral renal or renal arterial disease, plasma renin activity (PRA), renin substrate (PRS), and angiotensin II (AT II) concentrations were measured in both renal veins and in a peripheral vein 1-2 h after stimulation of renin secretion by injection of frusemide. In patients with elevated PRA in venous blood from a kidney with RAS, AT II was either also elevated, lower than or equal to PRA in peripheral blood, while the contralateral kidney almost invariably extracted AT II. In the 8 patients with variable renal diseases, the concordance between PRA and AT II measurements was better. Results suggest that AT II measurements in renal venous blood are less useful in assessing the functional significance of a RAS than those of PRA. Since PRS is not different in venous plasma of the diseased and the normal kidney, PRA measurements can be regarded as proportional to plasma renin concentration in this condition.

Renal venous thrombosis

In neonates, thrombosis beginning in small renal veins and progressing to larger veins is best termed renal venous thrombosis (RVT) since the renal vein is not usually concerned. RVT occurs dominantly in the new-born and affects males more often than females (2:1). Hyperosmolality, maternal prediabetes and angiocardiography contribute to the occurrence or RVT. Early signs and symptoms are largely non-specific with the most reliable being the presence of haematuria (49%) or a palpably enlarged and hard kidney (60%). A falling platelet count, raised FDP level of falling plasminogen level support the diagnosis in 90% of cases. Radiology and nephrosonography are very useful in establishing the presence or absence and functional state of the kidneys. Therapy consists of the maintenance of homeostasis, minimization of spread, correction of uraemia and prevention of renal hypertension from a contracted functionless kidney by elective nephrectomy after 4--6 months. Heparin therapy and peritoneal dialysis have greatly improved the outlook in bilateral cases.

Renal secretion of inactive renin

Human plasma contains a non-dialyzable factor which is not enzymatically active in its native form but shows renin-like activity after exposure to low pH (inactive renin). In 3 out of 13 patients with renovascular hypertension the renal to peripheral vein ratio for inactive renin on the affected side was above 1.40, indicating renal release of this form of renin. In 4 cases a high renal to peripheral vein ratio for active renin was associated with a ratio for inactive renin below 0.80, indicating renal activation of circulating inactive renin. The results suggest a renal mechanism for modulating the degree of activation of renin. They have some practical implications for the pre-operative evaluation of patients with renovascular hypertension.

Correlation between evolution and treatment of hypertension in unilateral renal disease and values of renin activity in renal venous blood

93 patients with renal hypertension and renal vein PRA determination were studied during 1--5 years follow-up. They were separated in two groups of medical and surgical treatment. Medical treatment is able to normalize blood pressure even in cases with high asymmetric PRA. 9 of 16 patients could be cured or improved in the surgical group and 14 of 22 in the medical group. The best results were obtained if beta-blockers were included in the drug regimen: cured or improved were 7 of 33 patients in medical treatment without beta-blockers, 17 of 28 in surgical treatment, and 31 of 32 in medical treatment including beta-blockers with or without hydralazine and/or diuretics.

Effects of saralasin on blood pressure, renin and renal blood flow in unilateral renovascular hypertension

The effect of saralasin, a competitive inhibitor of angiotensin II, was assessed in hypertensive patients with unilateral renal artery stenosis after furosemide application. A significant fall of systemic arterial blood pressure, an increase of renal venous renin activity, significantly on the stenosed side in patients without arteriosclerosis of the contralateral kidney, and an almost equal decrement of renal blood flow in both kidneys were observed. Conceivably saralasin exerts different sodium-dependent effects on peripheral angiotensin II and specific intrarenal vascular receptors.

Relevant diagnostic procedures in renovascular hypertension

The validity of invasive preoperative diagnostic procedures in patients with unilateral renovascular hypertension was assessed. A significant lowering of blood pressure following reconstructive surgery can be predicted if following stimulation with Dihydralazine the renal-venous renin ratio of the involved to the noninvolved kidney is at least 2.0. Furthermore, it is of importance to determine the renal perfusion rate in the contralateral non-stenotic kidney which should be within normal limits. If these two criteria are met then in the majority of cases surgical intervention in unilateral hypertension is meaningful.

Renal extraction and acute effects of glucagon-like peptide-1 on central and renal hemodynamics in healthy men

The present experiments were performed to elucidate the acute effects of intravenous infusion of glucagon-like peptide (GLP)-1 on central and renal hemodynamics in healthy men. Seven healthy middle-aged men were examined on two different occasions in random order. During a 3-h infusion of either GLP-1 (1.5 pmol·kg⁻¹·min⁻¹) or saline, cardiac output was estimated noninvasively, and intraarterial blood pressure and heart rate were measured continuously. Renal plasma flow, glomerular filtration rate, and uptake/release of hormones and ions were measured by Fick's Principle after catheterization of a renal vein. Subjects remained supine during the experiments. During GLP-1 infusion, both systolic blood pressure and arterial pulse pressure increased by 5±1 mmHg (P=0.015 and P=0.002, respectively). Heart rate increased by 5±1 beats/min (P=0.005), and cardiac output increased by 18% (P=0.016). Renal plasma flow and glomerular filtration rate as well as the clearance of Na⁺ and Li⁺ were not affected by GLP-1. However, plasma renin activity decreased (P=0.037), whereas plasma levels of atrial natriuretic peptide were unaffected. Renal extraction of intact GLP-1 was 43% (P<0.001), whereas 60% of the primary metabolite GLP-1 9-36amide was extracted (P=0.017). In humans, an acute intravenous administration of GLP-1 leads to increased cardiac output due to a simultaneous increase in stroke volume and heart rate, whereas no effect on renal hemodynamics could be demonstrated despite significant extraction of both the intact hormone and its primary metabolite.

Indications for renal autotransplant: an overview

Advances in transplantation led to the first renal autotransplant in 1963 performed due to high ureteral injury sustained during aortic surgery. The procedure involves excision of the kidney and autologous re-implantation. Subsequently, multiple cases of renal autotransplantation have been reported in the literature for a range of indications. This reviews aims to assess the literature and experiences reported to assess the varying indications for renal autotransplant. The evidence and literature generated from experiences in this procedure are largely limited to case reports and relatively small or moderately sized case series. The main indications reported for performing autotransplant broadly includes renovascular disease, ureteral pathology and neoplastic disease. The advent of laparoscopic techniques and their implications on renal autotransplant also are discussed. Varying degrees of success are reported with this procedure with controversial issues surrounding this procedure remain, particularly in the area of neoplastic surgery. Renal autotransplant may be a useful last resort in preventing kidney loss in highly selected circumstances and when conventional methods have failed.

[It's not always a cyst]

Congenital arteriovenous renal fistulas are rare malformations due to abnormal communications between arterial and the venous systems. There are two types of congenital arteriovenous malformations: crisoid or, as in the present study, aneurysmal. Hematuria is the major and most common symptom, along with other clinical manifestations, such as hypertension, left ventricular hypertrophy, cardiac failure, and abdominal pain, but the congenital aneurysmatic arteriovenous renal fistulas can be also asymptomatic. Diagnosis can arise from a focused survey, suggested by a medical case or to be occasional, as in the present case of study. Ultrasonography with color duplex studies is the first line of imaging studies used in the diagnosis of renal arteriovenous malformations, The differential diagnosis must be made with other anechoic lesion: abscesses, tumors, hydronephrosis or, as in this case, a renal cyst. Angiography is the gold standard in the diagnosis of arteriovenous malformations, especially in those cases where the diagnostic -therapeutic treatment requires the endovascular treatment of the vessel, as in the case of a 46 years old man submitted in our clinic to the ultrasonography follow-up for a renal cyst.

Fatal hyperkalemia following succinylcholine administration in a child on oral propranolol

Succinylcholine is one of the most commonly used drugs by anesthesiologists worldwide for rapid access to airway both in emergency and elective situations. Nonetheless, the very mention of succinylcholine generates the most energetic high decibel debate between its users and nonusers. Despite its potential to produce a short-acting, ultra-intense neuromuscular block rapidly in seconds, it is surrounded by a plethora of side effects and drug interactions. This case report is about one such drug interaction of this innocent yet malicious drug, which resulted in the death of a 14-year-old girl. Both β-adrenergic blockers and succinylcholine are known to cause hyperkalemia. Life-threatening hyperkalemia in susceptible individuals who have been administered succinylcholine has the most severe effect on the myocardium and can result in asystole with minimal chances of resuscitation. Both succinylcholine and a nonselective β-adrenergic blocker, propranolol, have the propensity to affect the transcellular redistribution of potassium which can result in hyperkalemia. We advocate cautious use of this drug combination till further studies confirm the drug interaction and find the potential triggering factors involved.

Leiomyosarcoma of the Inferior Vena Cava Level II Including Both Renal Veins : Surgical Approach

A 66 years old male developping an acute lower right limb oedema due to an extended venous thrombosis of the common femoral and iliac veins was diagnosed to have a leiomyosarcoma of the inferior vena cava (IVC) involving both renal veins. The characteristics and management of this level II IVC leiomyosarcoma are discussed with particular attention to the renal vein reconstruction and neo-adjuvant therapy.