Assessing the Effects of Geniculate Artery Embolization in a Nonsurgical Animal Model of Osteoarthritis.

PURPOSE: To create a nonsurgical animal model of osteoarthritis (OA) to evaluate the effects of embolotherapy during geniculate artery embolization (GAE). MATERIALS AND METHODS: Fluoroscopy-guided injections of 700 mg of sodium monoiodoacetate were performed into the left stifle in 6 rams. Kinematic data were collected before and after induction. At 10 weeks after induction, Subjects 1 and 4-6 underwent magnetic resonance (MR) imaging with dynamic contrast enhancement (DCE) and Subjects 1, 3, and 4-6 underwent angiography with angiographic scoring to identify regions with greatest disease severity for superselective embolization (75-250-µm microspheres). Target vessel size was measured. At 24 weeks after angiography, DCE-MR imaging, angiography, and euthanasia were performed, and bilateral stifles were harvested. Medial/lateral tibial and femoral condylar, patellar, and synovial samples were cut, preserved, decalcified, and scored using the Osteoarthritis Research Society International criteria. The stifle and synovium Whole-Organ Magnetic Resonance Imaging Score and Multicenter Osteoarthritis Study score were determined. The volume transfer constant (Ktrans) and extracellular volume fraction (ve) were calculated from DCE-MR imaging along the lateral synovial regions of interest. RESULTS: The mean gross and microscopic pathological scores were elevated at 38 and 61, respectively. Mean synovitis score was elevated at 9.2. Mean pre-embolization and postembolization angiographic scores were 5 and 3.8, respectively. Mean superior, transverse, and inferior geniculate artery diameters were 3.1 mm ± 1.21, 2.0 mm ± 0.50, and 1.6 mm ± 0.41 mm, respectively. Mean pre-embolization and postembolization cartilage and synovitis scores were elevated at 35.13 and 73.3 and 5.5 and 9.2, respectively. The Ktrans/ve values of Subjects 4, 5, and 6 were elevated at 0.049/0.38, 0.074/0.53, and 0.065/0.51, respectively. Altered gait of the hind limb was observed in all subjects after induction, with reduced joint mobility. No skin necrosis or osteonecrosis was observed. CONCLUSIONS: A nonsurgical ovine animal knee OA model was created, which allowed the collection of angiographic, histopathological, MR imaging, and kinematic data to study the effects of GAE.

Hemorrhagic Shock/Resuscitation Reduces the M2 Phenotype of Alveolar Macrophages: A Potential Mechanism Contributing to Increased LPS-Induced Lung Injury.

Major hemorrhage is a significant contributor to the morbidity and mortality resulting from traumatic injury. In addition to its role in in early mortality, hemorrhagic shock followed by resuscitation (HS/R) is known to initiate immunological events that contribute to the development of organ dysfunction. The pathogenesis of acute lung injury following HS/R involves macrophage activation. Recent studies have shown that macrophage function may in part be regulated by polarization toward classical M1 pro-inflammatory cells or alternatively activated anti-inflammatory M2 cells. We hypothesized that alteration in the M1/M2 phenotypic balance of alveolar macrophages in the lung may contribute to a pro-inflammatory state following HS/R. Using a murine model, we show that HS/R causes a rapid reduction in surface cluster of differentiation (CD)206 and CD36, markers of M2 cells, as well as in CD206 messenger ribonucleic acid (mRNA). M1 markers including surface CD80 and tumour necrosis factor alpha and inducible nitric oxide synthase mRNA were increased, albeit in a somewhat delayed time course. The prostaglandin 5-deoxyDelta12,14 prostaglandin J2 (15d-PGJ2), known to polarize cells toward M2, restored levels of M2 macrophages toward control and prevented lung injury, as assessed by bronchoalveolar protein content. Adoptive cell transfer of in vitro M2 polarized macrophages also reduced lung inflammation/injury following hemorrhagic shock. Together, these studies demonstrate that HS/R increases M1/M2 ratio, predominantly by lowering M2 cells, and thus enhances the proinflammatory state. Various strategies aimed at promoting M2 polarization may lessen the magnitude of inflammation and injury. This represents a novel approach to the prevention/treatment of lung injury in critically ill trauma patients.

Nephrocutaneous Fistula due to Xanthogranulomatous Pyelonephritis.

While the development of a fistulous tract from the kidney to the proximal adjacent organs is relatively common, a tract leading to the skin is a rare occurrence. The primary cause of a fistula is prior surgical intervention or malignancy leading to abscess formation. Our case involves Xanthogranulomatous pyelonephritis (XGP) causing a longstanding lobulated abscess, ultimately leading to the formation of a fistulous tract.

Benefit of feeding tube placement for refractory malnutrition after bariatric surgery.

BACKGROUND: Bariatric surgery provides durable weight loss and decreases the incidence of co-morbid conditions for people with obesity. Most patients benefit from resultant weight loss, but some are at risk for postoperative refractory malnutrition, a serious but poorly understood complication. OBJECTIVE: To evaluate differences in bariatric surgery patients who received a feeding tube postoperatively for malnutrition compared with other indications. SETTING: Retrospective cohort study at an academic bariatric surgery center (1985-2015). METHODS: All bariatric surgery patients that received a feeding tube postoperatively over a 30-year period were identified. Data abstraction from the medical record was performed to assess demographic characteristics, operative details, tube indication, and resultant body mass index (BMI) changes. RESULTS: From a total of 3487 patients who underwent bariatric surgery during the study period, 139 (3.9%) required placement of a feeding tube postoperatively. Refractory malnutrition was the indication in 24 patients, all after Roux-en-Y gastric bypass. There were no significant differences between these patients and other bariatric surgery patients in terms of mean age (40.6±9.9 versus 43.1±13.4 years, P = .4) and preoperative BMI (47.5±10.5 versus 51.0±9.6 kg/m2, P = .1). The median time from surgery to tube placement for malnutrition patients was 4 years. Compared with other feeding tube indications, malnutrition patients had higher percent excess BMI lost after surgery (126.2±31.9 versus 52.5±44.3%, P<.0001). After tube placement, malnutrition patients had a significant increase in mean BMI compared with other indications (14.5±20.9 versus-13.0±14.0%, P< .001). CONCLUSION: Patients with refractory malnutrition benefit from feeding tube placement, which results in a significant increase in BMI.

Bariatric surgery insurance requirements independently predict surgery dropout.

BACKGROUND: Many insurance companies have considerable prebariatric surgery requirements despite a lack of evidence for improved clinical outcomes. The hypothesis of this study is that insurance-specific requirements will be associated with a decreased progression to surgery and increased delay in time to surgery. METHODS: Retrospective data collection was performed for patients undergoing bariatric surgery evaluation from 2010-2015. Patients who underwent surgery (SGY; n = 827; mean body mass index [BMI] 49.1) were compared with those who did not (no-SGY; n = 648; mean BMI: 49.4). Univariate and multivariate analysis were performed to identify specific co-morbidity and insurance specific predictors of surgical dropout and time to surgery. RESULTS: A total of 1475 patients using 12 major insurance payors were included. Univariate analysis found insurance requirements associated with surgical drop out included longer median diet duration (no-SGY = 6 mo; SGY = 3 mo; P<.001); primary care physician letter of necessity (P<.0001); laboratory testing (P = .019); and evaluation by cardiology (P<.001), pulmonology (P<.0001), or psychiatry (P = .0003). Using logistic regression to control for co-morbidities, longer diet requirement (odds ratio [OR] .88, P<.0001), primary care physician letter (OR .33, P<.0001), cardiology evaluation (OR .22, P = .038), and advanced laboratory testing (OR 5.75, P = .019) independently predicted surgery dropout. Additionally, surgical patients had an average interval between initial visit and surgery of 5.8±4.6 months with significant weight gain (2.1 kg, P<.0001). CONCLUSION: Many prebariatric surgery insurance requirements were associated with lack of patient progression to surgery in this study. In addition, delays in surgery were associated with preoperative weight gain. Although prospective and multicenter studies are needed, these findings have major policy implications suggesting insurance requirements may need to be reconsidered to improve medical care.