Failure rates of nonoperative management of low-grade splenic injuries with active extravasation: an Eastern Association for the Surgery of Trauma multicenter study.

Objectives: There is little evidence guiding the management of grade I-II traumatic splenic injuries with contrast blush (CB). We aimed to analyze the failure rate of nonoperative management (NOM) of grade I-II splenic injuries with CB in hemodynamically stable patients. Methods: A multicenter, retrospective cohort study examining all grade I-II splenic injuries with CB was performed at 21 institutions from January 1, 2014, to October 31, 2019. Patients >18 years old with grade I or II splenic injury due to blunt trauma with CB on CT were included. The primary outcome was the failure of NOM requiring angioembolization/operation. We determined the failure rate of NOM for grade I versus grade II splenic injuries. We then performed bivariate comparisons of patients who failed NOM with those who did not. Results: A total of 145 patients were included. Median Injury Severity Score was 17. The combined rate of failure for grade I-II injuries was 20.0%. There was no statistical difference in failure of NOM between grade I and II injuries with CB (18.2% vs 21.1%, p>0.05). Patients who failed NOM had an increased median hospital length of stay (p=0.024) and increased need for blood transfusion (p=0.004) and massive transfusion (p=0.030). Five patients (3.4%) died and 96 (66.2%) were discharged home, with no differences between those who failed and those who did not fail NOM (both p>0.05). Conclusion: NOM of grade I-II splenic injuries with CB fails in 20% of patients. Level of evidence: IV.

Chronic hypertension increases aortic endothelial hydraulic conductivity by upregulating endothelial aquaporin-1 expression.

Numerous studies have examined the role of aquaporins in osmotic water transport in various systems, but virtually none have focused on the role of aquaporin in hydrostatically driven water transport involving mammalian cells save for our laboratory's recent study of aortic endothelial cells. Here, we investigated aquaporin-1 expression and function in the aortic endothelium in two high-renin rat models of hypertension, the spontaneously hypertensive genetically altered Wistar-Kyoto rat variant and Sprague-Dawley rats made hypertensive by two-kidney, one-clip Goldblatt surgery. We measured aquaporin-1 expression in aortic endothelial cells from whole rat aortas by quantitative immunohistochemistry and function by measuring the pressure-driven hydraulic conductivities of excised rat aortas with both intact and denuded endothelia on the same vessel. We used them to calculate the effective intimal hydraulic conductivity, which is a combination of endothelial and subendothelial components. We observed well-correlated enhancements in aquaporin-1 expression and function in both hypertensive rat models as well as in aortas from normotensive rats whose expression was upregulated by 2 h of forskolin treatment. Upregulated aquaporin-1 expression and function may be a response to hypertension that critically determines conduit artery vessel wall viability and long-term susceptibility to atherosclerosis.NEW & NOTEWORTHY The aortic endothelia of two high-renin hypertensive rat models express greater than two times the aquaporin-1 and, at low pressures, have greater than two times the endothelial hydraulic conductivity of normotensive rats. Data are consistent with theory predicting that higher endothelial aquaporin-1 expression raises the critical pressure for subendothelial intima compression and for artery wall hydraulic conductivity to drop.

Revisiting the NIH Stroke Scale as a screening tool for proximal vessel occlusion: can advanced imaging be targeted in acute stroke?

BACKGROUND AND PURPOSE: Most patients with stroke-like symptoms screened by advanced imaging for proximal occlusion will not have a thrombus accessible by neurointerventional techniques. Development of a sensitive clinical scoring system for rapidly identifying patients with an emergent large vessel occlusion could help target limited resources and reduce exposure to unnecessary imaging. METHODS: This historical cohort study included patients who underwent non-contrast CT and CT angiography in the emergency department for stroke-like symptoms. NIH Stroke Scale (NIHSS) criteria were extended to include resolved symptoms and dichotomized as present or absent. Combinations of NIHSS criteria were considered as tests for proximal occlusion. RESULTS: Proximal cerebral vascular occlusion was present in 19.2% (100/522) of the population and, of these, 13% (13/100) had an NIHSS score of 0. The presence on examination or history of diminished consciousness with inability to answer questions, leg weakness, dysarthria, or gaze deviation had 96% sensitivity and 39% specificity for proximal occlusion. If implemented in this population, the use of CT angiography would have been decreased by 32.4% (169/522 patients) while missing 0.76% with proximal occlusions (4/522). Half of those missed (2/4) would have been identified as large vessel infarcts on non-contrast CT, while the remainder (2/4) were transient ischemic attacks associated with carotid stenosis. CONCLUSIONS: In this cohort, specific NIHSS criteria were highly sensitive for emergent large vessel occlusion and, if validated, may allow for clinical screening prior to advanced imaging with CT angiography.

Safety and effectiveness of large volume coils in the treatment of small aneurysms.

BACKGROUND AND PURPOSE: Large volume soft design coils facilitate quicker aneurysm filling and high packing density. Our purpose was to analyze the feasibility, safety, and effectiveness of the Penumbra Coil 400 (PC400) system in the treatment of small aneurysms. MATERIALS AND METHODS: A retrospective analysis of prospective data collected at three different centers was performed on consecutive aneurysms <10 mm treated with the PC400 system. A total of 92 aneurysms were included in the study. Feasibility, procedure safety, angiographic and clinical results, and follow-up results were evaluated. RESULTS: Mean aneurysm size was 5.8±2.0 mm. An average of 2.5±1.3 coils with a mean length of 18±16 cm per aneurysm was used, resulting in a mean packing density of 45.6±14.4%. The thromboembolic event rate was 3.3% and no procedural aneurysm rupture was observed. Immediate adequate occlusion was achieved in 66% of aneurysms. During a mean follow-up period of 7.4 months the number of adequate occlusions increased to 91%. CONCLUSIONS: Large volume PC 400 coils are safe and effective in the treatment of small aneurysms with a low thromboembolic complication rate and no hemorrhagic events. High packing densities are achieved with a low average number of coils used per aneurysm treated. The aneurysms demonstrated progressive occlusion over time, which probably suggests stability in the long term.

Metabolic characterization of nondiabetic severely obese patients undergoing Roux-en-Y gastric bypass: preoperative classification predicts the effects of gastric bypass on insulin-glucose homeostasis.

INTRODUCTION: Obese individuals may have normal insulin-glucose homeostasis, insulin resistance, or diabetes mellitus. Whereas gastric bypass cures insulin resistance and diabetes mellitus, its effects on normal physiology have not been described. We studied insulin resistance and beta-cell function for patients undergoing gastric bypass. METHODS: One hundred thirty-eight patients undergoing gastric bypass had fasting insulin and glucose levels drawn on days 0, 12, 40, 180, and 365. Thirty-one (22%) patients with diabetes mellitus were excluded from this analysis. Homeostatic model of assessment was used to estimate insulin resistance, insulin sensitivity, and beta-cell function. Based on this model, patients were categorized as high insulin resistance if their insulin resistance was >2.3. RESULTS: Body mass index did not correlate with insulin resistance. Forty-seven (34%) patients were categorized as high insulin resistance. Correction of insulin resistance for this group occurred by 12 days postoperatively. Sixty (43%) patients were categorized as low insulin resistance. They demonstrated an increase of beta-cell function by 12 days postoperatively, which returned to baseline by 6 months. At 1 year postoperatively, the low insulin resistance group had significantly higher beta-cell function per degree of insulin sensitivity. CONCLUSIONS: Adipose mass alone cannot explain insulin resistance. Severely obese individuals can be categorized by degree of insulin resistance, and the effect of gastric bypass depends upon this preoperative physiology.

Effect of hepatic artery flow on bile secretory function after cold ischemia.

These studies evaluated the influence of hepatic arterial flow on biliary secretion after cold ischemia. Preparation of livers for transplantation or hepatic support impairs biliary secretion. The earliest indication of cold preservation injury during reperfusion is circulatory function. Arterial flow at this time may be critical for bile secretion. Porcine livers were isolated, maintained at 4 degrees for 2 h and connected in an extracorporeal circuit to an anesthetized normal pig. The extracorporeal livers were perfused either by both the hepatic artery and portal vein (dual) or by the portal vein alone (single). Incremental doses of sodium taurocholate were infused into the portal vein of both the dual and single perfused livers, and the bile secretion was compared. Most endogenous bile acids are lost during hepatic isolation. After supplementation, the biliary secretion of phosphatidyl choline and cholesterol was significantly better in the dual than single vessel-perfused livers; however, no difference was seen in bilirubin output. Single perfused livers were completely unable to increase biliary cholesterol in response to bile acid. The dependence of bile cholesterol secretion on arterial flow indicates the importance of this flow to the detoxification of compounds dependent on phosphatidyl choline transport during early transplantation.

Early ambulation after diagnostic angiography using 4-f catheters and sheaths: a feasibility study.

PURPOSE: To assess the feasibility and safety of early ambulation in patients undergoing transfemoral diagnostic angiography using 4-F catheters or sheaths. METHODS: In this prospective study approved by the institutional review board, patients undergoing diagnostic angiography were randomized to ambulate 3 or 6 hours after catheter or sheath removal. All patients were assessed for hematoma formation, pseudoaneurysm development, and other groin complications during the in-hospital recovery period and after 30 days. Patient satisfaction and comfort level were also assessed by survey. RESULTS: Of 110 patients (66 men; mean age 64.9 +/- 12.8 years) who participated in this study, 47 were randomized to the 6-hour (6-H) group and 63 to the 3-hour (3-H) group. In the 3-H and 6-H groups, respectively, a 4-F catheter was used in 45 (71%) and 35 (74%) patients and a 4-F sheath in 18 (29%) and 12 (26%). No clinically significant groin complications were encountered in either group. Moderate to severe discomfort was reported in 9 (16%) of the 56 patients responding to the discomfort survey in the 3-H group compared to 10 (26%) of the 38 in the 6-H survey respondents. CONCLUSIONS: It is feasible and safe to ambulate patients 3 hours after diagnostic angiography performed with a 4-F catheter with or without a 4-F sheath. Early ambulation of patients after angiography has the additional benefits of increasing patient satisfaction and resource utilization.

Regulation of NFkappaB in hepatic ischemic preconditioning.

BACKGROUND: The second messengers tyrosine kinase (TK) and protein kinase C (PKC) have been implicated in mediating the cellular signaling cascade during hepatic ischemic preconditioning (IPC). We evaluated the role of TK and PKC on the modulation of the transcription factor nuclear factor kappa B (NFkappaB) and its inhibitor IkappaB alpha during IPC. STUDY DESIGN: Yorkshire pigs underwent routine harvest. IPC livers underwent 15 minutes of ischemia and 15 minutes of in situ perfusion before harvest, with or without pretreatment with a TK inhibitor (genistein) or a PKC inhibitor (chelerythrine). During cold storage and reperfusion, tissue extracts were analyzed for IkappaB alpha phosphorylation and NFkappaB levels and for TK and PKC activity by Western blot. RESULTS: Control pig livers demonstrated no change in the levels of TK, PKC, IkappaB alpha, or NFkappaB before cold ischemia. IPC grafts demonstrated activation of TK and PKC with increased IkappaB alpha phosphorylation and NFkappaB levels before cold ischemia. IPC grafts pretreated with genistein demonstrated inhibition of TK activation but not of PKC activation. Genistein-pretreated grafts also demonstrated inhibition of IkappaB alpha phosphorylation and a lack of NFkappaB translocation to the nucleus throughout the entire experiment. IPC grafts pretreated with chelerythrine demonstrated inhibition of PKC activation but not TK activation. Chelerythrine-pretreated grafts also demonstrated IkappaB alpha phosphorylation before cold ischemia and enhanced nuclear levels of NFkappaB. CONCLUSIONS: Data suggest that the role of TK in IPC might be mediated in part by NFkappaB, but PKC does not depend on NFkappaB for its effect. Two parallel signaling pathways might explain these data.

Results of iliac artery stent placement in patients younger than 50 years of age.

PURPOSE: To determine long-term outcome in patients 50 years of age or younger treated with iliac artery stent placement. MATERIALS AND METHODS: The records of 412 patients who underwent iliac artery stent placement during a 62-month study period were reviewed retrospectively. Forty-two patients younger than age 50 (mean age = 45 y) at the time of stent placement were included in the study population. Presenting symptoms included claudication (47%), rest pain (17%), ulceration/tissue loss (31%), and blue toe syndrome (5%). Anatomic, hemodynamic, and clinical success rates of the stent placement procedure were assessed. Stent patency rates were calculated by life-table methods. RESULTS: Fifty-nine iliac lesions were treated with stents; 62% of patients underwent treatment of a single lesion whereas 38% had multiple lesions treated. Thirty-one percent were treated after a failed angioplasty procedure and 69% were treated with stent placement primarily. After stent placement, 34 patients (82%) experienced symptomatic relief, although eight of these patients (19%) underwent a planned ipsilateral infrainguinal bypass procedure during the same hospitalization. During follow-up, five patients (12%) required a bypass procedure as a result of stent failure and two patients (5%) required below-knee amputation. Seven patients (17%) required endovascular stent revision, with none requiring additional surgery. At 1, 2, and 3 years, the primary patency rates were 86%, 72%, and 65%, and the secondary patency rates were 90%, 88%, and 88%, respectively. CONCLUSIONS: Iliac stent placement successfully addresses the presenting symptoms of young patients with peripheral vascular disease and results in patency rates that are similar to those reported in a more general population. With appropriate postprocedural surveillance, restenosis can be addressed in many patients with use of endovascular techniques, limiting the need for surgical revision.

Donor hepatic function: a factor in postreperfusion syndrome.

Reperfusion of support livers after cold preservation produces hemodynamic instability (i.e., postreperfusion syndrome) in the recipient during both orthotopic liver transplantation and extracorporeal liver perfusion. We evaluated the effect of the normal porcine cold-preserved support liver on healthy recipient hemodynamics and in situ liver function during extracorporeal liver perfusion. Support livers were harvested from Yorkshire pigs and reperfused in an extracorporeal circuit with a healthy, anesthetized recipient pig. Correlation analyses were performed between support liver variables of function (oxygen consumption, bile flow, and biliary phospholipid and cholesterol output) and both recipient hemodynamic stability (heart rate, blood pressure, urine output, and vasopressor use) and hepatic function (bile flow and biliary phospholipid secretion). The data indicate that optimally functioning support livers are associated with improved recipient hemodynamic stability manifested by decreased recipient heart rate and vasopressor use and increased recipient urine output. Support livers exhibiting poor biliary secretory function (i.e., bile flow and phospholipid output) were associated with similarly diminished recipient liver biliary secretory function. These data indicate that the functional condition of the support liver after harvest and cold preservation may influence both recipient hemodynamic parameters and the endogenous function of the recipient liver.

Porcine hepatic phospholipid efflux during reperfusion after cold ischemia.

BACKGROUND: Cold preservation produces hepatic injury that is difficult to assess during early reperfusion. The value of reperfusion plasma choline phospholipid in predicting subsequent organ function is documented in these studies. MATERIALS AND METHODS: Livers of female Yorkshire pigs were prepared for transplantation. After 2 h of cold ischemia the reperfusion plasma was evaluated for choline phospholipid and cholesterol. These values were correlated with bile secretion, hepatic hemodynamics, oxygen uptake, and plasma sorbitol dehydrogenase levels. RESULTS: The isolated porcine liver demonstrates a rapid efflux of choline phospholipids into plasma during early reperfusion after cold preservation. After this initial efflux no subsequent plasma increment occurred. These choline-phospholipid increments were isolated in plasma higher density (d > 1.063) lipoproteins and were not accompanied by equivalent increases in cholesterol. Neither biliary reflux nor lecithin cholesterol acyl transferase abnormalities contributed appreciably to the phospholipid increments in reperfusion plasma. Livers with the largest efflux of choline phospholipids had the most impaired circulatory and bile secretory function at 4 h of reperfusion. CONCLUSION: The immediate increase of choline phospholipids, particularly lysophosphatidylcholine, in reperfusion plasma after cold ischemia provides an index of the injury occurring during this interval and correlates with early organ function.