Vascularized Biomaterials to Study Cancer Metastasis.

Cancer metastasis, the spread of cancer cells to distant organs, is responsible for 90% of cancer-related deaths. Cancer cells need to enter and exit circulation in order to form metastases, and the vasculature and endothelial cells are key regulators of this process. While vascularized 3D in vitro systems have been developed, few have been used to study cancer, and many lack key features of vessels that are necessary to study metastasis. This review focuses on current methods of vascularizing biomaterials for the study of cancer, and three main factors that regulate intravasation and extravasation: endothelial cell heterogeneity, hemodynamics, and the extracellular matrix of the perivascular niche.

Clinical outcomes following identification of tip appendicitis on ultrasonography and CT scan.

BACKGROUND/PURPOSE: With recent improvements in imaging technology, subtler variations in the anatomy of the appendix can be appreciated. We hypothesized that radiographic findings of tip appendicitis may not correlate strongly with a pathologic diagnosis of appendicitis. METHODS: Our radiology database was searched for reports of a diagnosis of tip appendicitis between January 2013 and June 2017 for patients between the ages of 2 and 17. Retrospective chart review was performed for demographic and clinical data, including outcomes. For patients managed operatively, the pathology results were reviewed for evidence of acute appendicitis. Patients managed nonoperatively and those with negative pathology were considered to not have appendicitis. RESULTS: Fifty-five patients met inclusion criteria (31 boys and 24 girls); 46/55 patients with tip appendicitis on imaging ultimately did not have appendicitis. Twenty-one patients underwent appendectomy, and 9/21 had pathologic evidence of appendicitis. One patient had a ruptured appendix. No other pathology was identified in the negative appendectomies. Two patients managed nonoperatively required readmission, but not secondary to missed diagnosis of appendicitis. CONCLUSIONS: Ultrasound and CT findings of tip appendicitis may not accurately associate with a final diagnosis of acute appendicitis. Clinical judgment should ultimately dictate appropriate initial management, follow-up tests, and imaging. TYPE OF STUDY: Diagnostic Study. LEVEL OF EVIDENCE: Level III.

A Novel Macroscale Acoustic Device for Blood Filtration.

Retransfusion of a patient's own shed blood during cardiac surgery is attractive since it reduces the need for allogeneic transfusion, minimizes cost, and decreases transfusion related morbidity. Evidence suggests that lipid micro-emboli associated with the retransfusion of the shed blood are the predominant causes of the neurocognitive disorders. We have developed a novel acoustophoretic filtration system that can remove lipids from blood at clinically relevant flow rates. Unlike other acoustophoretic separation systems, this ultrasound technology works at the macroscale, and is therefore able to process larger flow rates than typical micro-electromechanical system (MEMS) scale acoustophoretic separation devices. In this work, we have first demonstrated the systematic design of the acoustic device and its optimization, followed by examining the feasibility of the device to filter lipids from the system. Then, we demonstrate the effects of the acoustic waves on the shed blood; examining hemolysis using both haptoglobin formation and lactate dehydrogenase release, as well as the potential of platelet aggregation or inflammatory cascade activation. Finally, in a porcine surgical model, we determined the potential viability of acoustic trapping as a blood filtration technology, as the animal responded to redelivered blood by increasing both systemic and mean arterial blood pressure.

Surgical Stabilization of Rib Fractures: A Single Institution Experience.

BACKGROUND: Use of surgical stabilization of rib fractures (SSRF) has increased. Despite compelling small studies, many centers still struggle with determining criteria for intervention. We investigated the benefit of SSRF in our patients compared with nonoperative (NonOp) National Trauma Databank (NTDB) controls, specifically in the older population. STUDY DESIGN: We performed a retrospective comparison of trauma patients with ≥3 and >5 rib fractures, who underwent SSRF at a tertiary care level I trauma center, with nonoperatively managed NTDB controls from equivalent level I centers between 2007 and 2014. The main outcomes measures included mortality, pneumonia, length of stay (LOS), ICU LOS, ventilator use, and tracheostomy rates. RESULTS: Overall, SSRF patients were older, had a higher percentage of respiratory disease, and higher Injury Severity Scores (ISS). Despite more respiratory disease in SSRF patients vs NonOp (p < 0.0001), there was no difference in ventilator usage. Results of SSRF included decreases in mortality (12%, p = 0.008) and pneumonia (13%, p < 0.001) compared with NonOp on propensity score matching. On subgroup analysis of patients 65 years of age or older, ISS was higher in the SSRF group. Mortality was significantly lower for SSRF vs NonOp, even with higher frequency of respiratory disease within the group (p < 0.001). CONCLUSIONS: Patients who underwent SSRF at our institution had improved outcomes despite a higher percentage of respiratory disease, compared with patients who were managed nonoperatively nationwide. Mortality rates improved for patients aged 65 and older, suggesting that this patient population may benefit more from SSRF.

A case report of unexpected pathology within an incarcerated ventral hernia.

INTRODUCTION: Incidence of hernial appendicitis is 0.008%, most frequently within inguinal and femoral hernias. Up to 2.5% of appendectomy patients are found to have Crohn's disease. Elucidating the etiology of inflammation is essential for directing management. PRESENTATION OF CASE: A 51-year-old female with achondroplastic dwarfism, multiple cesarean sections, and subsequent massive incisional hernia, presented with ruptured appendicitis within her incarcerated hernia. She underwent diagnostic laparoscopy, appendectomy, intra-abdominal abscess drainage, and complete reduction of ventral hernia contents. She developed a nonhealing colocutaneous fistula, causing major disruptions to her daily life. She elected to undergo hernia repair with component separation for anticipated lack of domain secondary to her body habitus. Her operative course consisted of open abdominal exploration, adhesiolysis, colocutaneous fistula repair, ileocolic resection and anastomosis, and hernia repair with bioresorbable mesh. She tolerated the procedure well. Unexpectedly, ileocolic pathology demonstrated chronic active ileitis, diagnostic of Crohn's disease. DISCUSSION: Only two cases of hernial Crohn's appendicitis have been reported, both within Spigelian hernias. Appendiceal inflammation inside a hernia sac may be attributed to ischemia from extraluminal compression of the hernia neck. This case demonstrates a rare presentation of multiple concurrent surgical disease processes, each of which impact the patient's treatment plan. CONCLUSION: This is the first report of incisional hernia appendicitis with nonhealing colocutaneous fistulas secondary to Crohn's. It is a lesson in developing a differential diagnosis of an inflammatory process within an incarcerated hernia and management of the complications related to laparoscopic hernial appendectomy in a patient with undiagnosed Crohn's disease.

Laparoscopic Pediatric Inguinal Hernia Repair: A Pilot Study in a Novel Guinea Pig Animal Model.

BACKGROUND: The purpose of this study was to compare different techniques for pediatric laparoscopic inguinal hernia repair. We hypothesize that the amount of dissection performed at the internal ring, with or without division of the peritoneum, will impact healing and thus long-term success of the repair. METHODS: Following the Institution's Animal Care and Use Committee approval (708024-4), 20 Hartley guinea pigs underwent laparoscopic repair of their natural open internal rings. The guinea pigs were divided equally into four surgical groups: intracorporeal suture repair (IS), hernia dissection and division with intracorporeal suture (DDIS) repair, subcutaneous endoscopically assisted ligation (SEAL), and Yueng (HOOK) repair. After a 6-week survival period, a necropsy was performed. Repairs were evaluated and tested under pressures up to 30 mmHg. The suture was then removed to assess primary healing. Experimental data were analyzed using chi-square test. RESULTS: There were no perioperative or postoperative complications. On initial evaluation, before suture removal, repair integrity was as follows: 5/10 IS, 10/10 DDIS, 7/10 SEAL, and 7/10 HOOK (P = .09). After suture removal, repair integrity was as follows: 3/10 IS, 10/10 DDIS, 5/10 SEAL, and 6/10 HOOK (P = .01). CONCLUSION: Overall, dissecting and dividing the sac with intracorporeal suture (DDIS) closure had the best outcome. This method appears to best replicate standard open high ligation.

Operative vs Nonoperative Management of Pediatric Blunt Pancreatic Trauma: Evaluation of the National Trauma Data Bank.

BACKGROUND: Traumatic pancreatic injury is associated with significant morbidity and mortality. We evaluated the differences in outcomes among children with blunt pancreatic injuries managed operatively and nonoperatively. STUDY DESIGN: The National Trauma Data Bank was evaluated from 2002 to 2011. Patients less than18 years of age with blunt pancreatic injuries and Abbreviated Injury Scale (AIS) scores ≥ 3 were identified. Patients were divided into nonoperative (NO), operative (O), and delayed operative (DO; operation performed 48 hours or more after admission) groups. Outcomes evaluated were total length of stay (LOS), ICU use/LOS, complications, and death. Univariate comparisons were performed using Fisher's exact and Kruskal-Wallis rank tests. Multivariable analyses were performed using robust regression and logistic regression. RESULTS: There were 424 cases analyzed. Mean (± SD) age was 10.6 ± 5.3 years, and mean Injury Severity Score (ISS) was 23.4 ± 13.4. Operative groups differed by age (p = 0.002), AIS severity (p = 0.04), and concomitant head injury (p = 0.01), but were similar with regard to sex, race, and ISS. Length of stay was significantly higher in the DO group compared with the NO or O groups; the NO group had the lowest LOS (covariate-adjusted: 18.7 days vs 11.8 days, p < 0.001 and 12.6 days, p < 0.001, respectively) and infection rates (10.2% vs 1.6% and 6.2%, respectively, p = 0.04). The ICU LOS was greatest in the DO group (vs NO, p = 0.03; O, p = 0.29), as was the likelihood of ICU use (vs NO, p = 0.02; O, p = 0.75). Groups did not differ with respect to outcomes including death (p = 0.94) and overall complication rate (p = 0.63). CONCLUSIONS: Overall, children managed nonoperatively have equivalent or better outcomes when compared with operative and delayed operative management in regard to death, overall complications, LOS, ICU LOS, and ICU use.