Developing a medical device-grade T2 phantom optimized for myocardial T2 mapping by cardiovascular magnetic resonance.

INTRODUCTION: A long T2 relaxation time can reflect oedema, and myocardial inflammation when combined with increased plasma troponin levels. Cardiovascular magnetic resonance (CMR) T2 mapping therefore has potential to provide a key diagnostic and prognostic biomarkers. However, T2 varies by scanner, software, and sequence, highlighting the need for standardization and for a quality assurance system for T2 mapping in CMR. AIM: To fabricate and assess a phantom dedicated to the quality assurance of T2 mapping in CMR. METHOD: A T2 mapping phantom was manufactured to contain 9 T1 and T2 (T1|T2) tubes to mimic clinically relevant native and post-contrast T2 in myocardium across the health to inflammation spectrum (i.e., 43-74 ms) and across both field strengths (1.5 and 3 T). We evaluated the phantom's structural integrity, B0 and B1 uniformity using field maps, and temperature dependence. Baseline reference T1|T2 were measured using inversion recovery gradient echo and single-echo spin echo (SE) sequences respectively, both with long repetition times (10 s). Long-term reproducibility of T1|T2 was determined by repeated T1|T2 mapping of the phantom at baseline and at 12 months. RESULTS: The phantom embodies 9 internal agarose-containing T1|T2 tubes doped with nickel di-chloride (NiCl2) as the paramagnetic relaxation modifier to cover the clinically relevant spectrum of myocardial T2. The tubes are surrounded by an agarose-gel matrix which is doped with NiCl2 and packed with high-density polyethylene (HDPE) beads. All tubes at both field strengths, showed measurement errors up to ≤ 7.2 ms [< 14.7%] for estimated T2 by balanced steady-state free precession T2 mapping compared to reference SE T2 with the exception of the post-contrast tube of ultra-low T1 where the deviance was up to 16 ms [40.0%]. At 12 months, the phantom remained free of air bubbles, susceptibility, and off-resonance artifacts. The inclusion of HDPE beads effectively flattened the B0 and B1 magnetic fields in the imaged slice. Independent temperature dependency experiments over the 13-38 °C range confirmed the greater stability of shorter vs longer T1|T2 tubes. Excellent long-term (12-month) reproducibility of measured T1|T2 was demonstrated across both field strengths (all coefficients of variation < 1.38%). CONCLUSION: The T2 mapping phantom demonstrates excellent structural integrity, B0 and B1 uniformity, and reproducibility of its internal tube T1|T2 out to 1 year. This device may now be mass-produced to support the quality assurance of T2 mapping in CMR.

Knockout Genes in Bowel Anastomoses: A Systematic Review of Literature Outcomes.

BACKGROUND: The intestinal wound healing process is a complex event of three overlapping phases: exudative, proliferative, and remodeling. Although some mechanisms have been extensively described, the intestinal healing process is still not fully understood. There are some similarities but also some differences compared to other tissues. The aim of this systematic review was to summarize all studies with knockout (KO) experimental models in bowel anastomoses, underline any recent knowledge, and clarify further the cellular and molecular mechanisms of the intestinal healing process. A systematic review protocol was performed. MATERIALS AND METHODS: Medline, EMBASE, and Scopus were comprehensively searched. RESULTS: a total of eight studies were included. The silenced genes included interleukin-10, the four-and-one-half LIM domain-containing protein 2 (FHL2), cyclooxygenase-2 (COX-2), annexin A1 (ANXA-1), thrombin-activatable fibrinolysis inhibitor (TAFI), and heparin-binding epidermal growth factor (HB-EGF) gene. Surgically, an end-to-end bowel anastomosis was performed in the majority of the studies. Increased inflammatory cell infiltration in the anastomotic site was found in IL-10-, annexin-A1-, and TAFI-deficient mice compared to controls. COX-1 deficiency showed decreased angiogenesis at the anastomotic site. Administration of prostaglandin E2 in COX-2-deficient mice partially improved anastomotic leak rates, while treatment of ANXA1 KO mice with Ac2-26 nanoparticles reduced colitis activity and increased weight recovery following surgery. CONCLUSIONS: our findings provide new insights into improving intestinal wound healing by amplifying the aforementioned genes using appropriate gene therapies. Further research is required to clarify further the cellular and micromolecular mechanisms of intestinal healing.

Portomesenteric Vein Thrombosis in Patients Undergoing Sleeve Gastrectomy: an Updated Systematic Review and Meta-Analysis of 101,914 Patients.

INTRODUCTION: Portomesenteric vein thrombosis (PMVT) is a rare but potentially fatal complication of sleeve gastrectomy (SG). The rising prevalence of SG has led to a surge in the occurrence of PMVT, while the associated risk factors have not been fully elucidated. This study aims to determine the incidence and risk factors of PMVT in patients undergoing SG. METHODS: A comprehensive literature search was performed in PubMed and EMBASE databases. Proportion and regression meta-analyses were conducted. RESULTS: In a total of 76 studies including 101,914 patients undergoing SG, we identified 357 patients with PMVT. Mean follow-up was 14.4 (SD: 16.3) months. The incidence of PMVT was found to be 0.50% (95%CI: 0.40-0.61%). The majority of the population presented with abdominal pain (91.8%) at an average of 22.4 days postoperatively and PMVT was mainly diagnosed with computed tomography (CT) (96.0%). Hematologic abnormalities predisposing to thrombophilia were identified in 34.9% of the population. Advanced age (p=0.02) and low center volume (p <0.0001) were significantly associated with PMVT, while gender, BMI, hematologic abnormality, prior history of deep vein thrombosis or pulmonary embolism, type of prophylactic anticoagulation, and duration of prophylactic anticoagulation were not associated with the incidence of PMVT in meta-regression analyses. Treatment included therapeutic anticoagulation in 93.4% and the mortality rate was 4/357 (1.1%). CONCLUSION: PMVT is a rare complication of sleeve gastrectomy with an incidence rate <1% that is associated with low center volume and advanced age but is not affected by the duration or type of thromboprophylaxis administered postoperatively.

Systemic inflammatory changes and their clinical implications following thoracic cancer surgery.

Trauma that follows every surgical procedure triggers an inflammatory response, which in the majority of the cases reflects the associated tissue damage. Tissue regeneration, postoperative outcomes, and systemic antibacterial activity are highly dependent on the initial inflammatory response elicited by surgical trauma. More specifically, in thoracic surgery, systemic cytokine and cellular changes have an impact on several measured postoperative outcomes. Lastly, the introduction of video-assisted and robotic-assisted thoracic surgery has been shown to provide improved postoperative outcomes with altered systemic inflammatory response, when compared to open thoracic surgery. This review outlines the major systemic inflammatory changes observed in thoracic cancer surgery as well as its clinical significance.

Anastomotic Leak in Ovarian Cancer Cytoreduction Surgery: A Systematic Review and Meta-Analysis.

INTRODUCTION: Anastomotic leaks (AL) following ovarian cytoreduction surgery could be detrimental, leading to significant delays in commencing adjuvant chemotherapy, prolonged hospital stays and increased morbidity. The aim of this study was to investigate risk factors associated with anastomotic leaks after ovarian cytoreduction surgery. MATERIAL AND METHODS: The MEDLINE (via PubMed), Cochrane Library, EMBASE and Scopus bibliographical databases were searched. Original clinical studies investigating risk factors for AL in ovarian cytoreduction surgery were included. RESULTS: Eighteen studies with non-overlapping populations reporting on patients undergoing cytoreduction surgery for ovarian cancer (n = 4622, including 344 cases complicated by AL) were included in our analysis. Patients undergoing ovarian cytoreduction surgery complicated by AL had a significantly higher rate of 30-day mortality but no difference in 60-day mortality. Multiple bowel resections were associated with an increased risk of postoperative AL, while no association was observed with body mass index (BMI), American Society of Anesthesiologists (ASA) score, age, smoking, operative approach (primary versus interval cytoreductive, stapled versus hand-sewn anastomoses and formation of diverting stoma), neoadjuvant chemotherapy and use of hyperthermic intraperitoneal chemotherapy (HIPEC). DISCUSSION: Multiple bowel resections were the only clinical risk factor associated with increased risk for AL after bowel surgery in the ovarian cancer population. The increased 30-day mortality rate in patients undergoing ovarian cytoreduction complicated by AL highlights the need to minimize the number of bowel resections in this population. Further studies are required to clarify any association between neoadjuvant chemotherapy and decreased AL rates.