Extravascular stent management for migration of left renal vein endovascular stent in nutcracker syndrome

Nutcracker syndrome (a Delphi consensus)

BACKGROUND

Nutcracker syndrome (NCS) describes the symptomatic compression of the left renal vein between the aorta and superior mesenteric artery. Whereas asymptomatic compression is a common radiological finding, patients with NCS can report a range of symptoms. There are no specific diagnostic criteria and interventions include a range of open surgical and endovascular procedures. Therefore, we wished to develop an international consensus document covering aspects of diagnosis, management, and follow-up for patients with NCS.

METHODS

A three-stage modified Delphi consensus was performed. A steering committee developed 37 statements covering 3 categories for patients with NCS: diagnosis, management, and follow-up. These statements were reported individually by 20 international experts in the management of venous disease, using a 5-point Likert scale. Consensus was defined if ≥70% of respondents rated the statement between 1 and 2 (agreement) and between 4 and 5 (disagreement). Those statements without consensus were recirculated in a second round of voting. A third round of the questionnaire was performed with 14 additional statements to clarify diagnostic values of NCS.

RESULTS

Responses were returned by 20 of 20 experts (100%) in round one and 17 of 20 (85%) in round two. Initial consensus was reached in 24 of 37 statements (65%) spread over all categories. Round two achieved a further consensus on 5 out of 10 statements (50%). No categories reported consensus on all statements. In round two consensus was reached in the category of follow-up (4/5 statements [80%]). The final round reached consensus on 5 out of 14 statements (36%). Experts agreed that imaging is obligated to confirm NCS. Experts did not agree on specific diagnostic cut-off values. There was a consensus that the first choice of operative treatment is left renal vein transposition and that the risk of stent migration outweighs the advantages of a percutaneous procedure.

CONCLUSIONS

Consensus was achieved on most statements concerning the assessment and management of NCS. This Delphi consensus identified those areas in which further research is needed, such as antiplatelet therapy, endovascular treatment, and renal autotransplantation. A rare disease registry to improve data and reports of patient outcomes is warranted.

Laparoscopic placement of left renal vein extravascular stenting in treatment of nutcracker syndrome: Techniques and long-term outcomes

OBJECTIVES

We aimed to assess the feasibility and efficacy of laparoscopic extravascular stent in treatment of nutcracker syndrome by transperitoneal or retroperitoneal approach.

METHODS

Seventy-six patients with nutcracker syndrome were retrospectively enrolled from a tertiary referral center, and underwent transperitoneal (63 patients) or retroperitoneal (13 patients) laparoscopic extravascular stent from March 2011 to December 2020. Surgical parameters, complications, imaging and clinical outcomes were collected and analyzed.

RESULTS

All procedures were successfully carried out without open conversion. The median operation time, estimated blood loss, and postoperative hospital day were 120 (interquartile range [IQR]: 90-144) min, 20 (IQR: 10-30) ml, and 7 (IQR: 6-9) days. At a median follow-up of 52 (range: 9-127) months, 60 (79%) patients had complete symptom resolution, 14 (18%) patients had significant symptom improvement, and 2 (3%) patients reported no symptom improvement. Ninety-four percent (50/53) of hematuria, 91% (30/33) of proteinuria, and 89% (25/28) of flank/abdominal pain resolved after extravascular LRV stenting. No significant differences were detected in surgery parameters and recovery rates of clinical symptoms between two approaches (each p > 0.05). However, patients with transperitoneal approach need longer to achieve complete recovery compared with retroperitoneal approach (8.7 vs. 1.5 months, p = 0.016).

CONCLUSIONS

Laparoscopic extravascular stent performed either transperitoneally or retroperitoneally is a feasible and effective option in treatment of nutcracker syndrome. Retroperitoneal laparoscopic extravascular stent required shorter time to achieve complete recovery, which should be considered whenever possible in surgical decision-making.

Stent in left renal vein stuck at the opening of tricuspid valve

A 41-year-old male patient attended the hospital suffering from chest tightness and intermittent chest pain. Through cardiac ultrasonography, a metallic foreign body was found in the right ventricle, accompanied by tricuspid insufficiency. Chest computed tomography scan further confirmed a foreign body stuck at the opening of the tricuspid valve. The 14 × 40mm stent was removed from the right ventricular through thoracotomy. One month ago, the patient received left renal venous stenting for treatment of Nutcracker Syndrome. Thus, for patients who have received left renal venous stenting for treatment of Nutcracker Syndrome, clinicians should pay due attention to stent-graft migration.

Left renal vein transposition for posterior Nutcracker syndrome

Nutcracker syndrome (NCS) is a rare cause of pelvic venous congestion syndrome and is secondary to either compression of the left renal vein in its normal anatomic position by the superior mesenteric artery and aorta or less commonly when the left renal vein is in a retroaortic position, compressed between the aorta and the spine. We herein present a unique case of NCS in a female patient with a history of chronic pelvic pain and venous congestion. We also review the literature and discuss the diagnostic modalities, differential diagnosis, and various open surgical and endovascular options for NCS.

Venous Stent Migrating to the Right Heart Causing Severe Regurgitation

Venous stent migration to the cardiopulmonary system is a rare but serious complication. Cardiopulmonary involvement has various presentations such as valvulopathy, acute heart failure, arrhythmias, endocarditis, and tamponade. The presenting symptoms depend on the eventual location of the stent in the heart or lungs, size of the stent, and valve involvement. Extracardiac dislodgement can be managed by catheter-directed extraction or proper deployment within the containing vessel or surgical extraction. Intracardiac stents may require open surgery to prevent life-threatening complications. We present an asymptomatic patient with stent migration that lead to severe tricuspid regurgitation and required tricuspid valve replacement

Endovascular treatment of anterior nutcracker syndrome and pelvic varices in a patient with an anterior and a posterior renal vein

There are few data on endovascular treatment of anterior nutcracker syndrome and pelvic varices in patients with anterior and posterior renal veins. Our objective is to report a case, identify occurrences and compare diagnosis and treatments. A 42-year-old woman presented with flank and pelvic pain and hematuria. She had anterior nutcracker syndrome and pelvic varices with an anterior and a posterior renal vein. A successful complete endovascular approach was done with stent implantation in the anterior renal vein and left gonadal vein embolisation. After 12-month follow-up, the patient remained asymptomatic with good results on CT. Only two case reports of patients with nutcracker syndrome with anterior and posterior renal veins were identified. In both, a self-expanding stent was implanted in the anterior renal vein. In conclusion, endovascular treatment represents a safe and successful option in patients with nutcracker syndrome and pelvic varices with an anterior and a posterior renal vein.

3D-Printed PEEK Extravascular Stent in the Treatment of Nutcracker Syndrome: Imaging Evaluation and Short-Term Clinical Outcome

Minimally invasive options are safe and reliable alternatives for the treatment of nutcracker syndrome (NCS). After continued efforts, our team successfully devised a new and effective therapeutic method: 3D-printed extravascular stenting of the left renal vein. From December 2017 to May 2019, 28 patients (25 men and 3 women) from different parts of China between 18 and 37 years old (mean, 23.6 years) diagnosed with NCS were admitted for laparoscopic 3D-printed extravascular stenting treatment. The post-operative follow-up duration was 6-24 months (median, 16.3 months). Technical success of the operation was achieved in all patients. After treatment, the NCS symptoms all patients resolved or improved during the follow-up period, without relapse. Most symptoms, including macro-/microhematuria, proteinuria, and flank/abdominal pain, tended to resolve within 3-6 months after the surgery; other symptoms, such as left-sided varicocele, also showed varying degrees of improvement at different times post-operatively. Perioperative complications were noted in two patients, including transient and mild lymphatic leakage, without any adverse effects. All extravascular stents were visualized on computed tomography and Doppler ultrasound scans, and no migration or any side effects occurred during the entire follow-up period. Compared to endovascular stenting or polytetrafluoroethylene artificial vessel procedures, 3D-printed polyetheretherketone extravascular stenting has more advantages in terms of stent design and rigidity and approach rationality while successfully preventing stent migration and thrombosis. Therefore, this method may serve as an accurate and effective treatment for NCS patients.

A minimally invasive alternative for the treatment of nutcracker syndrome using individualized three-dimensional printed extravascular titanium stents

BACKGROUND

This study was designed to evaluate the clinical and radiographic outcomes of patients with nutcracker syndrome (NCS) who were treated with three-dimensional printing (3DP) extravascular titanium stents (EVTSs). The 3DP EVTS was expected to release the hypertension of the left renal vein (LRV) produced by its compression between the superior mesenteric artery (SMA) and the aorta without causing any complications.

METHOD

The pre-operative kidney model of each patient was printed out to enable surgical planning. After that, the EVTS was designed based on the LRV's primitive physiologic structure using computer-aided design software, and each stent was printed out with a precision setting of 20 μm. Seventeen patients who had been suffering from NCS underwent laparoscopic 3DP EVTS placement. The surgical procedure was designed for the placement of EVTS, taking great care in positioning and fixing the stent. Surgical data, which included patient demographic characteristics as well as pre- and post-operative test results, were collected and analyzed.

RESULTS

The mean duration of surgery was 75 ± 9 min, and the mean blood loss was 20 ± 5 mL. Computed tomography examinations revealed that the pre- and post-operative angle between the SMA and the aorta ranged from 18.7° ± 4.3° to 48.0° ± 8.8° (P < 0.05); in patients with left varicocele, the mean diameter of the left spermatic vein ranged from 3.7 ± 0.5 to 1.3 ± 0.2 mm (P < 0.05). Moreover, Doppler ultrasound examinations showed that the peak velocity of blood flow at the hilar area ranged from 12.4 ± 3.3 to 18.5 ± 3.4 cm/s (P < 0.05). No side effects were observed in the 24 to 42 months following surgery.

CONCLUSION

The findings after 2 years of follow-up suggest that the 3DP EVTS is a safe and effective minimally invasive alternative for the treatment of NCS.

Diagnosis and treatment of the Nutcracker syndrome: a review of the last 10 years

The nutcracker syndrome is characterized by a group of clinical manifestations caused by compression of the Left Renal Vein. The main symptoms are: macro and micro hematuria, proteinuria, and flank pain. Diagnosis is usually made after excluding other causes, because there are no clinical criteria for diagnosis. Confirmation is by Doppler ultrasonography or computed tomography. Treatment can vary, depending on patient characteristics and the severity of the symptoms, while conservative treatment, open surgery, and endovascular surgery may be employed. Currently, open surgery is still the first-line treatment, but some less invasive approaches are gaining acceptance.

Robot-assisted laparoscopic extravascular stent for nutcracker syndrome

Minimally invasive treatment options are a safe and feasible alternative for treatment of nutcracker syndrome. Endovascular stenting has shown promising long-term resolution of symptoms but can be complicated by stent migration or thrombosis. Laparoscopic extravascular stent placement has shown promising results with the potential to avoid these complications. We report the first case of extravascular stent placement using the robotic approach for the treatment of nutcracker syndrome.

Endovascular Treatment of Nutcracker Syndrome

BACKGROUND

Nutcracker syndrome, or mesoaortic compression of the left renal vein (LRV), with associated symptoms related to venous hypertension in the left kidney, is a rare entity that may result in severe symptoms requiring operative intervention. We report on 3 patients who presented with nutcracker syndrome, including one patient with a circumaortic LRV resulting in posterior nutcracker syndrome, who underwent successful endovascular treatment with renal vein stenting. A review of existing literature on endovascular management of nutcracker syndrome follows.

METHODS

Three women (age range 28-43 years) presented with symptoms and imaging studies consistent with nutcracker syndrome. Symptoms included pelvic and flank pain in all 3 patients, and episodes of hematuria in 2 patients. Imaging studies demonstrated compression of the LRV between the superior mesenteric artery and aorta in 2 of the patients. The third patient was noted to have a circumaortic LRV.

RESULTS

All 3 patients underwent venography and LRV stenting. Stents included a 12 × 40 mm self-expanding nitinol stent, 14 × 60 mm WALLSTENT, and 16 × 40 mm WALLSTENT. All patients were placed on clopidogrel postoperatively. The duration of follow-up ranged from 6 to 27 months. At follow-up, all 3 patients reported significant symptomatic improvement, and duplex ultrasonography demonstrated stent patency in all.

CONCLUSIONS

Nutcracker syndrome is a rare condition that can be successfully treated with renal vein stenting via an endovascular approach. Results are encouraging at follow-up periods beyond 2 years.