Transjugular Intrahepatic Portosystemic Shunt and Thrombectomy (TIPS-Thrombectomy) for Symptomatic Acute Noncirrhotic Portal Vein Thrombosis.

PURPOSE: To report the safety and effectiveness of transjugular intrahepatic portosystemic shunt and mechanical thrombectomy (TIPS-thrombectomy) for symptomatic acute noncirrhotic portal vein thrombosis (NC-PVT). MATERIALS AND METHODS: Patients with acute NC-PVT who underwent TIPS-thrombectomy between 2014 and 2021 at a single academic medical center were retrospectively reviewed. Thirty-two patients were included (men, 56%; median age, 51 years [range, 39-62 years]). The causes for PVT included idiopathic (n = 12), prothrombotic disorders (n = 11), postsurgical sequelae (n = 6), pancreatitis (n = 2), and Budd-Chiari syndrome (n = 1). The indications for TIPS-thrombectomy included refractory abdominal pain (n = 14), intestinal venous ischemia (n = 9), ascites (n = 4), high-risk varices (n = 3), and variceal bleeding (n = 2). Variables studied included patient, disease, and procedure characteristics. Patients were monitored over the course of 1-year follow-up. RESULTS: Successful recanalization of occluded portal venous vessels occurred in all 32 patients (100%). Compared with pretreatment patency, recanalization with TIPS-thrombectomy resulted in an increase in patent veins (main portal vein [28% vs 97%, P < .001], superior mesenteric vein [13% vs 94%, P < .001], and splenic vein [66% vs 91%, P < .001]). Three procedure-related adverse events occurred (Society of Interventional Radiology grade 2 moderate). Hepatic encephalopathy developed in 1 (3%) of 32 patients after TIPS placement. At 1-year follow-up, return of symptoms occurred in 3 (9%) of 32 patients: (a) ascites (n = 1), (b) variceal bleeding (n = 1), and (c) intestinal venous ischemia (n = 1). The intention-to-treat 1-year portal vein and TIPS primary and secondary patency rates were 78% (25/32) and 100% (32/32), respectively. Seven patients required additional procedures, and the 1-year mortality rate was 3% (1/32). CONCLUSIONS: TIPS-thrombectomy is a safe and effective method for treating patients with symptomatic acute NC-PVT.

Spontaneous intraperitoneal haemorrhage of the gastric vessels.

A male in his 70s presented to the emergency department with sudden-onset abdominal pain and syncope. While in the emergency department, he developed worsening hypotension and anaemia. A CT angiogram was suggestive of abdominal apoplexy (spontaneous intraperitoneal haemorrhage), which was treated successfully with embolisation of the bleeding vessels. Spontaneous bleeding was thought to be related to his initiation of apixaban 1 week previously. The patient made an excellent recovery and was transitioned back to oral anticoagulation.

Lubricin deficiency in the murine lumbar intervertebral disc results in elevated torsional apparent modulus.

The purpose of this study was to investigate the mechanical consequences of proteoglycan 4 (Prg4) deficiency on intervertebral disc mechanics using a Prg4 knockout mouse model. Prg4, also called lubricin, was first identified as the boundary lubricant in synovial fluid but has subsequently been localized within a number of musculoskeletal tissues in areas subjected to shear and tensile stresses, including the intervertebral disc. The function of lubricin in the intervertebral disc has not been determined. Lumbar level 1-2 vertebral body-disc-vertebral body motion segments were isolated from Prg4 null mice and wild type (WT) litter mate controls. Disc dimensions were measured and motion segments were tested in axial loading and torsion. Torque measurements and disc dimensions were used to calculate the torsional apparent modulus for discs from Prg4 null and WT discs. Discs from Prg4 null mice had a significantly smaller mean transverse disc area (p=0.0057), with a significantly larger proportion of this area occupied by the nucleus pulposus (p<0.0001), compared to WT specimens. Apparent torsional moduli were found to be elevated in Prg4 null lumbar discs compared to WT controls at 10-10° (p=0.0048) and 10-30° (p=0.0127) rotation. This study suggests a functional role for Prg4 in the murine intervertebral disc. The absence of Prg4 was associated with an increased apparent torsional modulus and the structural consequences of Prg4 deficiency in the intervertebral disc, with expansion of the area of the nucleus pulposus relative to the transverse disc area in Prg4 null specimens.

Validation of porcine knee as a sex-specific model to study human anterior cruciate ligament disorders.

BACKGROUND: Animal models have long been considered an important modality for studying ACL injuries. However, to our knowledge, the value of these preclinical models to study sex-related phenomena associated with ACL injury and recovery has not been evaluated. QUESTIONS/PURPOSES: We asked whether (1) prominent anatomic and (2) biomechanical factors differ between female and male porcine knees, particularly those known to increase the risk of ACL injury. METHODS: Eighteen intact minipig knees (nine males, nine females) underwent MRI to determine the femoral bicondylar width, intercondylar notch size (width, area and index), medial and lateral tibial slope, ACL size (length, cross-sectional area, and volume), and medial compartment tibiofemoral cartilage thickness. AP knee laxity at 30°, 60°, and 90° flexion and ACL tensile structural properties were measured using custom-designed loading fixtures in a universal tensile testing apparatus. Comparisons between males and females were performed for all anatomic and biomechanical measures. The findings then were compared with published data from human knees. RESULTS: Female pigs had smaller bicondylar widths (2.9 mm, ratio=0.93, effect size=-1.5) and intercondylar notches (width: 2.0 mm, ratio=0.79, effect size=-2.8; area: 30.8 mm2, ratio=0.76, effect size=-2.1; index: 0.4, ratio=0.84, effect size=-2.0), steeper lateral tibial slope (4.3°, ratio=1.13, effect size=1.1), smaller ACL (length: 2.7 mm, ratio=0.91, effect size=-1.1; area: 6.8 mm2, ratio=0.74, effect size=-1.5; volume: 266.2 mm3, ratio=0.68, effect size=-1.5), thinner medial femoral cartilage (0.4 mm, ratio=0.8, effect size=-1.1), lower ACL yield load (275 N, ratio=0.81, effect size=-1.1), and greater AP knee laxity at 30° (0.7 mm, ratio=1.32, effect size=1.1) and 90° (0.5 mm, ratio=1.24, effect size=1.1) flexion compared with their male counterparts. These differences were significant for all parameters (p≤0.04). Observed sex-related differences were similar to those reported for the human knee. CONCLUSIONS: Significant differences exist between knees of male and female pigs with respect to prominent anatomic and biomechanical factors. Our findings strongly agreed with published data regarding human knees. CLINICAL RELEVANCE: The findings highlight the use of the porcine large animal model to study the role of sex on ACL injuries and surgical outcome. This validated preclinical model may facilitate the development of novel, sex-specific interventions to prevent and treat ACL injuries for male and female patients.

Increased platelet concentration does not improve functional graft healing in bio-enhanced ACL reconstruction.

PURPOSE: The use of an extracellular matrix scaffold (ECM) combined with platelets to enhance healing of an anterior cruciate ligament (ACL) graft ("bio-enhanced ACL reconstruction") has shown promise in animal models. However, the effects of platelet concentration on graft healing remain unknown. The objectives of this study were to determine whether increasing the platelet concentration in the ECM scaffold would (1) improve the graft biomechanical properties and (2) decrease cartilage damage after surgery. METHODS: Fifty-five adolescent minipigs were randomized to five treatment groups: untreated ACL transection (n = 10), conventional ACL reconstruction (n = 15) and bio-enhanced ACL reconstruction using 1× (n = 10), 3× (n = 10) or 5× (n = 10) platelet-rich plasma. The graft biomechanical properties, anteroposterior (AP) knee laxity, graft histology and macroscopic cartilage integrity were measured at 15 weeks. RESULTS: The mean linear stiffness of the bio-enhanced ACL reconstruction procedure using the 1× preparation was significantly greater than traditional reconstruction, while the 3× and 5× preparations were not. The failure loads of all the ACL-reconstructed groups were equivalent but significantly greater than untreated ACL transection. There were no significant differences in the Ligament Maturity Index or AP laxity between reconstructed knees. Macroscopic cartilage damage was relatively minor, though significantly less when the ECM-platelet composite was used. CONCLUSIONS: Only the 1× platelet concentration improved healing over traditional ACL reconstruction. Increasing the platelet concentration from 1× to 5× in the ECM scaffold did not further improve the graft mechanical properties. The use of an ECM-platelet composite decreased the amount of cartilage damage seen after ACL surgery.