Long-segment thoracoabdominal aortic occlusions in childhood

Developmental coarctation, hypoplasia, and occlusion of the abdominal aorta is a rare disease encompassing many differing etiologies and diverse methods of treatment. Long-segment thoracoabdominal aortic occlusion, an extreme manifestation of this disorder, has not previously been reported in children. Two pediatric patients with this entity, a 5- and 13-year-old with uncontrolled hypertension, underwent extensive arterial reconstructions for this entity and provided the impetus for this report. An ascending thoracic aorta to infrarenal aortic expanded polytetrafluoroethylene bypass was undertaken in the younger child. A distal thoracic aorto-bi-iliac artery expanded polytetrafluoroethylene bypass, with implantation of the left renal artery to one graft limb and a right renal artery bypass originating from the other limb, was performed in the older child. There were no major perioperative complications. Both patients were discharged with easily controlled blood pressures. They have remained normotensive at 13 and 14 months follow-up

Postoperative fluid collection after hybrid debranching and endovascular repair of thoracoabdominal aortic aneurysms

ObjectiveHybrid thoracic endovascular aneurysm repair (H-TEVAR) to include visceral and renal debranching has emerged as a potential therapeutic option for thoracoabdominal aneurysms (TAAA). This study was performed to characterize the frequently noted development of postoperative fluid collections surrounding the bypass grafts.MethodsAll patients undergoing H-TEVAR from 2000-2010 (n = 39, 43.6% male) were identified. One hundred thirty-two bypasses were constructed (median 4 per patient) using either polyester (30), thin-walled polytetrafluoroethylene (ePTFE, 100) or saphenous vein (2). Follow-up computed tomography (CT) imaging was routinely performed at 1 and 6 months, and annually thereafter.ResultsOf the 37 patients with one follow-up CT, 20 (54.1%) were found to have fluid collections. The natural history of the 17 patients with collections and further follow-up imaging was variable, with 2 resolving, 6 stable, and 9 enlarging. Two patients with collections developed evidence of graft infection requiring reoperation. Two patients with enlarging sterile collections required evacuation for symptoms. By multivariate analysis, both preoperative creatinine (P = .005) and number of bypasses constructed (P = .04) independently correlated with the development of a fluid collection.ConclusionsPostoperative fluid collections following hybrid debranching procedures identified in this series represent a unique complication not previously described. The subsequent clinical course of these fluid collections is variable and ranges from benign to frank graft infection and relate both to patient factors, as well as specific operative strategies. Longer-term studies with more robust numbers of patient numbers are warranted to determine whether this complication may limit the long-term durability of this procedure

Postoperative fluid collection after hybrid debranching and endovascular repair of thoracoabdominal aortic aneurysms

ObjectiveHybrid thoracic endovascular aneurysm repair (H-TEVAR) to include visceral and renal debranching has emerged as a potential therapeutic option for thoracoabdominal aneurysms (TAAA). This study was performed to characterize the frequently noted development of postoperative fluid collections surrounding the bypass grafts.MethodsAll patients undergoing H-TEVAR from 2000-2010 (n = 39, 43.6% male) were identified. One hundred thirty-two bypasses were constructed (median 4 per patient) using either polyester (30), thin-walled polytetrafluoroethylene (ePTFE, 100) or saphenous vein (2). Follow-up computed tomography (CT) imaging was routinely performed at 1 and 6 months, and annually thereafter.ResultsOf the 37 patients with one follow-up CT, 20 (54.1%) were found to have fluid collections. The natural history of the 17 patients with collections and further follow-up imaging was variable, with 2 resolving, 6 stable, and 9 enlarging. Two patients with collections developed evidence of graft infection requiring reoperation. Two patients with enlarging sterile collections required evacuation for symptoms. By multivariate analysis, both preoperative creatinine (P = .005) and number of bypasses constructed (P = .04) independently correlated with the development of a fluid collection.ConclusionsPostoperative fluid collections following hybrid debranching procedures identified in this series represent a unique complication not previously described. The subsequent clinical course of these fluid collections is variable and ranges from benign to frank graft infection and relate both to patient factors, as well as specific operative strategies. Longer-term studies with more robust numbers of patient numbers are warranted to determine whether this complication may limit the long-term durability of this procedure

The complete management of extremity vascular injury in a local population: A wartime report from the 332nd Expeditionary Medical Group/Air Force Theater Hospital, Balad Air Base, Iraq

Background: Although the management of vascular injury in coalition forces during Operation Iraqi Freedom has been described, there are no reports on the in-theater treatment of wartime vascular injury in the local population. This study reports the complete management of extremity vascular injury in a local wartime population and illustrates the unique aspects of this cohort and management strategy. Methods: From September 1, 2004, to August 31, 2006, all vascular injuries treated at the Air Force Theater Hospital (AFTH) in Balad, Iraq, were registered. Those in non-coalition troops were identified and retrospectively reviewed. Results: During the study period, 192 major vascular injuries were treated in the local population in the following distribution: extremity 70% (n = 134), neck and great vessel 17% (n = 33), and thoracoabdominal 13% (n = 25). For the extremity cohort, the age range was 4 to 68 years and included 12 pediatric injuries. Autologous vein was the conduit of choice for these vascular reconstructions. A strict wound management strategy providing repeat operative washout and application of the closed negative pressure adjunct was used. Delayed primary closure or secondary coverage with a split-thickness skin graft was required in 57% of extremity wounds. All patients in this cohort remained at the theater hospital through definitive wound healing, with an average length of stay of 15 days (median 11 days). Patients required an average of 3.3 operations (median 3) from the initial injury to definitive wound closure. Major complications in extremity vascular patients, including mortality, were present in 15.7% (n = 21). Surgical wound infection occurred in 3.7% (n = 5), and acute anastomotic disruption in 3% (n = 4). Graft thrombosis occurred in 4.5% (n = 6), and early amputation and mortality rates during the study period were 3.0% (n = 4) and 1.5% (n = 2), respectively. Conclusions: To our knowledge, this study represents the first large report of wartime extremity vascular injury management in a local population. These injuries present unique challenges related to complex wounds that require their complete management to occur in-theater. Vascular reconstruction using vein, combined with a strict wound management strategy, results in successful limb salvage with remarkably low infection, amputation and mortality rates

Prospective evaluation of the correlation between torso height and aortic anatomy in respect of a fluoroscopy free aortic balloon occlusion system

Background. To report the lengths of key torso vascular and to develop regression models that will predict these lengths, based on an external measure of torso height (EMTH, sternum to pubis) in the development of a fluoroscopy-free balloon occlusion system for hemorrhage control. Methods. We conducted a prospective, observational study at a Combat Support Hospital in Southern Afghanistan using adult male patients undergoing computed tomography (CT). EMTH was recorded using a tape measure and intra-arterial distance was derived from CT imaging. Regression models to predict distance from the common femoral artery (CFA) into the middle of aortic zone I (left subclavian artery to celiac trunk) and zone III (infrarenal aorta) were developed from a random 20% of the cohort and validated by the remaining 80%. Results. Overall, 177 male patients were included with a median (interquartile range [IQR]) age of 23 (8) years. The median (IQR) lengths of aortic zone I and III were 222 (24), 31 (9), and 92 (15) mm. The mid-zone distance from the left and right CFA to zone I were 423 (27) and 418 (29) and for zone III 232 (21) and 228 (22). Linear regression models demonstrated an accuracy between 99.3% to 100% at predicting the insertion distance required to place a catheter within the middle of each aortic zone. Conclusion. This study demonstrates the use of morphometric analysis in the development of a fluoroscopy-free balloon occlusion system for torso hemorrhage control. Further study in a larger population of mixed gender is required to further validate insertion models. (Surgery 2014;155:1044- 51.

Tor Pathway Regulates Rrn3p-dependent Recruitment of Yeast RNA Polymerase I to the Promoter but Does Not Participate in Alteration of the Number of Active Genes

Yeast cells entering into stationary phase decrease rRNA synthesis rate by decreasing both the number of active genes and the transcription rate of individual active genes. Using chromatin immunoprecipitation assays, we found that the association of RNA polymerase I with the promoter and the coding region of rDNA is decreased in stationary phase, but association of transcription factor UAF with the promoter is unchanged. Similar changes were also observed when growing cells were treated with rapamycin, which is known to inhibit the Tor signaling system. Rapamycin treatment also caused a decrease in the amount of Rrn3p-polymerase I complex, similar to stationary phase. Because recruitment of Pol I to the rDNA promoter is Rrn3p-dependent as shown in this work, these data suggest that the decrease in the transcription rate of individual active genes in stationary phase is achieved by the Tor signaling system acting at the Rrn3p-dependent polymerase recruitment step. Miller chromatin spreads of cells treated with rapamycin and cells in post-log phase confirm this conclusion and demonstrate that the Tor system does not participate in alteration of the number of active genes observed for cells entering into stationary phase