Unstable Carotid Artery Thrombus in a Patient With COVID-19 Infection.

We present a case of an unvaccinated, 43-year-old African American female patient with COVID-19 infection and clinical evidence of a left hemispheric stroke. A non-occlusive thrombus with a radiographic target lesion was identified on computed tomography angiography (CTA). A multi-disciplinary discussion regarding concern for embolization was provided due to its unstable nature, as well as evidence of recent stroke. Given her acute COVID-19 infection, symptomatology, and radiographic findings, it was concluded that the etiology of her stroke appeared most consistent with a hypercoagulable-related embolism rather than an atheroembolic event. The patient underwent left carotid artery thrombectomy with bovine patch angioplasty. Operative findings included: left carotid thrombus, minimal plaque after evacuation of the thrombus, and a small proximal internal carotid artery diameter. Given concern for stenosis with primary repair a bovine pericardial patch angioplasty was performed. We present a paradigm for extracranial carotid thrombectomy with therapeutic anticoagulation for COVID-related spontaneous arterial thrombosis.

Hybrid Paraclavicular Decompression for Venous Thoracic Outlet Syndrome with Primary Endovascular Reconstruction.

BACKGROUND: Venous thoracic outlet syndrome (vTOS) is characterized by severe stenosis and potential thrombosis of the axillary-subclavian vein (effort thrombosis) with significant effects on patient mobility, quality of life, and risks associated with possible anticoagulation. Treatment goals are aimed at symptomatic improvement and freedom from recurrent thrombosis. To date, there exist no clear protocols or recommendations on surgical approach that result in optimal outcomes. We highlight our institution's experience with a systematized, paraclavicular approach with intraoperative balloon angioplasty only, if needed. METHODS: This was a retrospective case series identifying 33 patients that underwent thoracic outlet decompression for vTOS from 2014 to 2021 via paraclavicular approach at Trinity Health Ann Arbor. Demographics, presenting symptoms, perioperative details, and follow-up details describing symptomatic improvement and imaging surveillance were obtained. RESULTS: The average age of our patients was 37 years with the most common presenting symptoms of pain and swelling (91%). The average time from diagnosis to thrombolysis for effort thrombosis was 4 days, with an average time to operative intervention of 46 days. All patients underwent a paraclavicular approach with full first rib resection, anterior and middle scalenectomy, subclavian vein venolysis, and intraoperative venogram. Of these, 20 (61%) underwent endovascular balloon angioplasty, 1 required balloon with stent placement, 13 (39%) required no additional intervention, and no patients required surgical reconstruction of the subclavian-axillary vein. Duplex imaging was used to evaluate recurrence in 26 patients at an average of 6 months postop. Of these, 23 demonstrated complete patency (89%), 1 demonstrated chronic nonocclusive thrombus, and 2 demonstrated chronic occlusive thrombus. Almost all our patients (97%) had moderate or significant improvement of their symptoms. None of our patients required a subsequent operation for recurrence of symptomatic thrombosis. The mode length of anticoagulation use postoperatively was 3 months, with an average use of 4.5 months. CONCLUSIONS: A systematized surgical approach of paraclavicular decompression for venous thoracic outlet syndrome with primary endovascular balloon angioplasty carries minimal morbidity with excellent functional results and symptomatic relief.

Use of Endoscopic Vein Harvest Yields Improved Outcomes in Popliteal Artery Aneurysm Repair.

BACKGROUND: There is growing literature showing that endoscopic vein harvest (EVH) is safe, with excellent patency rates and decreased wound complications when treating infrainguinal occlusive disease. Our institution has performed EVH since 2003 with a dedicated team of providers specializing in endoscopic vein harvest. The purpose of this study was to evaluate major outcomes of EVH as an adjunct to standard, open operative repair of popliteal artery aneurysms. METHODS: We performed a 12-year retrospective single-institution chart review from January 2005 to December 2017, identifying all patients undergoing popliteal artery aneurysm repair with EVH. Primary outcomes were procedural technical success, operative time, wound complication, major morbidity, and freedom from amputation. RESULTS: A total 37 limbs (in 31 patients) received EVH popliteal artery aneurysm repair at an average age of 65.2 ± 10 years; 65% of the patients presented without symptoms or with claudication and 35% with rest pain or tissue loss. Coexisting aneurysm was present in 68% of patients: 49% had contralateral popliteal artery aneurysms and 19% had concurrent aortic aneurysms. Of 37 limbs, 33 (89%) were treated through a medial approach with aneurysm ligation, and 4 patients (11%) were treated through a posterior approach. The average vein size was 4.4 ± 1.1 mm, with 86% harvested by the ipsilateral great saphenous vein. Average operative time was 3.89 ± 0.82 hr, with a median hospitalization of 2 days and a median of 1 day of intravenous narcotics use. Only 2 patients (5.4%) had Szilagyi class-2 surgical site infections remedied with debridement and antibiotics. Kaplan-Meier data showed a 5-year primary patency of 82.3% and primary-assisted patency of 88.2%. Additionally, 30-day primary patency was 89.2% and primary-assisted patency of 97.3%. CONCLUSIONS: EVH for popliteal aneurysmal disease provides a safe and efficacious means of popliteal artery aneurysm repair with shorter hospitalization, lower wound complication rates, and excellent long-term patency compared to standard open technique.

Successful paraclavicular surgical decompression for recurrent venous thoracic outlet syndrome following transaxillary first rib resection in an elite athlete.

OBJECTIVES: Recurrent effort thrombosis after prior surgical intervention for venous thoracic outlet syndrome (TOS) is an uncommon problem, and there are multiple alternative surgical approaches in the management of recurrent venous TOS. METHODS: We present a case of a 23 year-old female professional athlete who presented with arm swelling, pain, and recurrent effort thrombosis after prior transaxillary rib resection. Imaging at our institution revealed subclavian vein thrombosis, confirmed with dynamic venography, as well as a remnant first rib. RESULTS: Thrombolysis of the subclavian vein and balloon angioplasty was followed by paraclavicular thoracic outlet decompression with complete first rib resection. Success was confirmed with intraoperative dynamic venography demonstrating a patent subclavian vein and resulted in complete elimination of symptoms. CONCLUSION: Additional surgical decompression with complete medial first rib resection of remnant rib, which was potentially causing compression of the subclavian vein, may be necessary to prevent recurrent venous compression and thrombosis for venous TOS.

Outcomes of Dexmedetomidine with Local Regional Anesthesia in Carotid Endarterectomy.

BACKGROUND: Adequate sedation to complement regional techniques in carotid endarterectomy (CEA) can be challenging. Dexmedetomidine has both analgesic and amnesic properties and is reported to be a safe and acceptable alternative to conventional general endotracheal anesthesia (GETA). Outcomes observing dexmedetomidine in conjunction with regional anesthesia in CEA are not well described or known. OBJECTIVE: Compare the immediate (during hospitalization) and short-term (within 30 days of hospitalization) postoperative outcomes in patients who underwent CEA using GETA versus local regional anesthesia (LRA) alone versus dexmedetomidine with LRA at a single institution to determine whether dexmedetomidine is a safe adjunct and if there are anesthesia advantages over LRA alone. METHODS: A retrospective cohort study from January 2015 to December 2019 at Saint Joseph Mercy Ann Arbor. Patients were stratified into three groups based on anesthesia type: GETA, LRA, and dexmedetomidine (D) + LRA. Primary outcomes included stroke, myocardial infarction (MI), and death. Patient demographics were characterized and adjusted using propensity score weighting. RESULTS: Three hundred seventy nine patients met inclusion criteria; 182 patients in the GETA group, 66 in the D + LRA, and 131 in LRA. There were no significant differences across anesthesia groups in primary outcomes of stroke, MI, and death during the admission. The GETA group had significantly longer length of stay (LOS) compared to the D + LRA group (LOS = 1.51 days versus 0.85 days; P = 0.011) and the LRA group (LOS = 1.08 days; P = 0.003). However, there was no significant difference in hospital LOS between the D + LRA group and LRA only groups (P = 0.952). There was no significant difference between stroke (LRA 0.87%, GETA 0.85%, and LRA + Dex 3.52%), MI (LRA 0%, GETA 0.49%, LRA + Dex 0%), or death (LRA 5.24%, GETA 1.16%, LRA + Dex 0%), within 30 days between all three of the anesthesia groups. There was no significant difference in postoperative pain scores when comparing the GETA group (mean 1.3, standard deviation [SD] 2.5) to LRA (mean 1.2, SD 2.1) and between LRA and D + LRA (mean 0.9, SD 2.1). Procedure time (time of skin incision to closure) and total room time were comparable among all three anesthesia groups (LRA 2.2 hr, SD 2.2; GETA 2.1 hr, SD 0.5; LRA + Dex 2.1 hr, SD 0.5). CONCLUSIONS: The use of dexmedetomidine in addition to LRA is a safe and acceptable alternative to conventional GETA or LRA alone in CEA with shorter length of hospital stay when compared with GETA, improved patient tolerance based on physician observation, and similar rates of immediate and short-term complications and postoperative pain scores.

Ten-year experience of infrainguinal bypass with endoscopic vein harvest.

OBJECTIVES: There is conflicting data comparing minimally invasive vein harvest (MIVH) using endoscopic technique and open vein harvest (OVH) in terms of bypass patency, wound infection incidence, and patient morbidity. Our institution has performed MIVH since 2003 for peripheral bypass procedures with a consistent team of specialized endoscopic vein harvesters. This study reviewed the major outcomes of MIVH infrainguinal bypass at our institution given a predominant cohort of critical limb ischemia. METHODS: We performed a 10-year, retrospective, single-institution review from January 2005 to December 2014, identifying all patients undergoing MIVH for obstructive infrainguinal disease. Primary outcomes were primary patency, operative time, intraoperative complications, surgical site infection (SSI), and freedom from amputation. RESULTS: A total of 289 patients (70% male) underwent MIVH infrainguinal bypass at an average age of 68 ± 12 years old, an obesity prevalence of 28%, and with critical limb ischemia in 81% of the patient cohort (20% rest pain, 61% tissue loss/gangrene). Ninety-four percent of patients had no intraoperative complications, 2.5% had adverse cardiac or technical complications, and 4.2% of patients required transfusion. Average operative time was 4.2 h. Femoral-popliteal TASC classification C and D constituted 80% of our patient cohort. At the last follow-up, toe pressures had increased from 30 ± 30 to 62 ± 40 mmHg (p < 0.0001). Primary bypass patency in the first 30 days was 95%. SSI incidence requiring surgical treatment was only 6%. Our median length of stay was 4.0 days, with median intravenous narcotic use of 1 day. In addition, 77% of patients returned to their baseline mobility at first follow-up (median 19 days), and 83% of patients had freedom from amputation at last follow-up (median 820 days). CONCLUSIONS: In a center with experience in MIVH and a consistent group of experienced endoscopic vein harvesters, MIVH bypass has excellent patency, low surgical site infection, short length of stay, and prompt return to baseline mobility.

Efficacy and utilization of intravascular ultrasound in office-based lower extremity endovascular interventions for peripheral arterial disease.

OBJECTIVES: Intravascular ultrasound (IVUS) is a uniquely objective but underutilized imaging modality in the interventional treatment of peripheral arterial disease treatment. IVUS has been shown to improve device size selection and diagnose occult pathology difficult to see with routine angiography. We hypothesize that the use of IVUS in lower extremity endovascular intervention improves accuracy in stent and balloon size selection and minimizes contrast use. METHODS: This is a retrospective case series performed at a single-institution outpatient center by two vascular surgeons from July 2016 through July 2017. We identified 94 total IVUS-assisted procedures. We collected data regarding demographics, balloon and stent size, IVUS-determined vessel diameter, pre-procedure and post-procedure ABI values, and contrast used during the procedure. An independent core laboratory was further utilized to characterize all IVUS and angiographic size vessel measurements. RESULTS: For the 94 lower extremity IVUS-assisted interventions, the average patient age was 70±9 years old, with an average contrast use of 37.1 mL of Omnipaque 300. There was substantial improvement in pre- and post-procedure ABI (0.7±0.23 to 0.94±0.21). On analysis of average intraluminal IVUS vessel diameter to balloon angioplasty used, we had a correlation in size of 0.96±0.16 in our series. Additionally, in eight instances IVUS allowed for identification of a flow-limiting dissection with subsequent stenting. CONCLUSIONS: Routine use of IVUS offers a powerful diagnostic paradigm that has the potential to significantly decrease contrast use and to improve objectivity in choosing appropriate vascular tools to maximize intra-procedural efficacy. The discovery of adverse findings not initially noticed on angiography further reinforces the value of IVUS utilization.

A statewide quality improvement collaborative significantly improves quality metric adherence and physician engagement in vascular surgery.

BACKGROUND: Quality improvement national registries provide structured, clinically relevant outcome and process-of-care data to practitioners-with regional meetings to disseminate best practices. However, whether a quality improvement collaborative affects processes of care is less clear. We examined the effects of a statewide hospital collaborative on the adherence rates to best practice guidelines in vascular surgery. METHODS: A large statewide retrospective quality improvement database was reviewed for 2013 to 2019. Hospitals participating in the quality improvement collaborative were required to submit adherence and outcomes data and meet semiannually. They received an incentive through a pay for participation model. The aggregate adherence rates among all hospitals were calculated and compared. RESULTS: A total of 39 hospitals participated in the collaborative, with attendance of surgeon champions at face-to-face meetings of >85%. Statewide, the hospital systems improved every year of participation in the collaborative across most "best practice" domains, including adherence to preoperative skin preparation recommendations (odds ratio [OR], 1.83; 95% confidence interval [CI], 1.76-1.79; P < .001), intraoperative antibiotic redosing (OR, 1.09; 95% CI, 1.02-1.17; P = .018), statin use at discharge for appropriate patients (OR, 1.18; 95% CI, 1.16-1.2; P < .001), and reducing transfusions for asymptomatic patients with hemoglobin >8 mg/dL (OR, 0.66; 95% CI, 0.66-0.66; P < .001). The use of antiplatelet therapy at discharge remained high and did not change significantly during the study period. Teaching hospital and urban or rural status did not affect adherence. The adherence rates exceeded the professional society mean rates for guideline adherence. CONCLUSIONS: The use of a statewide hospital collaborative with incentivized semiannual meetings resulted in significant improvements in adherence to "best practice" guidelines across a large, heterogeneous group of hospitals.

Rapid, midline retroperitoneal exposure for four-level anterior lumbar interbody fusion-technical case atlas.

We describe a novel, rapid midline retroperitoneal operative technique in a patient, with multi-level degenerative scoliosis, who underwent an extensive L2-S1 anterior lumbar interbody fusion in addition to posterior instrumentation. Uniquely, our approach enables an essentially midline approach to the rectus muscle and uses the diminution of the transversalis fascia-to-peritoneum transition in the pelvis to provide expedited exposure-making it particularly helpful for ALIF exposure, retraction and intraoperative radiography. We minimize morbidity around the rectus sheath by dissecting only the medial rectus muscle and then gently, bluntly mobilizing the retroperitoneum from the deep pelvis cranially.

Hybrid-based iliofemoral endarterectomy for severe and complete iliofemoral occlusive disease.

OBJECTIVE: Primary endovascular approaches are now the dominant modality for the treatment of iliac occlusive disease. However, stenting of the external iliac artery is plagued with high in-stent restenosis rates. This hybrid approach with fluoroscopic, retrograde iliofemoral endarterectomy combined with stenting was previously demonstrated to be both a safe and effective alternative to bypass and primary stenting alone for TransAtlantic Inter-Society Consensus (TASC) II C and D lesions. In this study, early outcomes and hemodynamic improvements of this hybrid approach are evaluated with an expanded patient population. METHODS: This was a single-institution, retrospective review of all hybrid-based retrograde iliofemoral endarterectomies from the common femoral artery extending to the proximal external iliac artery from January 1, 2010, to November 15, 2017. Data were collected from the electronic medical record and analyzed using standard quantitative statistical techniques. All preprocedure and postprocedure imaging was independently reviewed by two vascular surgeons. Variables included patient demographics, degree of ischemia, and stent characteristics. The primary outcomes were mortality and freedom from amputation, with secondary outcomes including changes in the ankle-brachial index and toe pressure. RESULTS: The procedure was performed on 63 limbs in 51 total patients. In 33 limbs, the indication was critical limb ischemia (tissue loss/gangrene = 17, rest pain = 16) and 30 for lifestyle-limiting claudication. The cohort consisted of 84% TASC D and 16% TASC C. External iliac stenting was required in 68% (modal diameter, 10 mm) and ipsilateral common iliac stenting was completed in 75% (modal diameter, 9 mm). The ankle-brachial index significantly improved from 0.42 ± 0.25 to 0.73 ± 0.27 (P < .001) as did toe pressure from 29 ± 27 mm Hg to 59 ± 34 mm Hg (P < .001). Thirteen limbs ultimately required an infrainguinal procedure. One patient experienced an intraoperative iliac perforation that resolved with stenting. One death occurred within 90 days. Ninety-five percent of patients remained free from amputation. CONCLUSIONS: Extensive hybrid-based, retrograde iliofemoral endarterectomy with stenting is a safe and efficacious approach to severe iliac arterial occlusive disease, with excellent early outcomes. This series promulgates the hypothesis that extensive endarterectomy with selective iliac stenting yields superior results to external iliac stenting alone. Given the superb hemodynamic improvements in a larger patient population, this hybrid-based, extensive iliofemoral endarterectomy should be recommended as a minimally invasive, first-line treatment for severe iliac occlusive disease.

Giant External Iliac Artery Aneurysm.

Isolated external iliac artery aneurysms are a very rare occurrence. We present the case of a patient with a very large symptomatic isolated external iliac artery aneurysm found incidentally on imaging for other reasons. Due to his compressive symptoms, he underwent uncomplicated open repair of his aneurysm. We also discuss the etiology and management options for this rare entity.

Prophylactic Groin Wound Vacuum-assisted Therapy in Vascular Surgery Patients at Enhanced Risk for Postoperative Wound Infection.

BACKGROUND: Vascular groin wounds have higher than expected surgical site infection (SSI) rates and some patients are at enhanced risk. The Wiseman et al. paper suggests an objective scoring system that identifies patients at enhanced risk of postdischarge SSI. We hypothesize that prophylactic groin wound vacuum-assisted closure (VAC) therapy in enhanced risk patients will decrease SSI and readmission and the Wiseman model provides potential evidence that enhanced risk patients can be objectively identified. METHODS: A single institution, retrospective analysis was conducted from January 2013 to September 2016 utilizing procedure codes to identify patients with wound VACs placed in the operating room. Two distinct groups were identified. The first was a wound complication patient group with 15 limbs (13 patients) with a groin wound VAC placed within 45 days postoperatively for groin wound complications. Eleven of these limbs had the VAC placed at readmission. The second group was a prophylactic patient group that included 8 limbs (7 patients) who received a VAC prophylactically placed in the enhanced risk wounds. These wounds were determined to be enhanced risk based on clinical criteria judged by the operating surgeon such as a large overhanging panniculus and/or one of several ongoing medical issues. We calculated a Wiseman score for all patients, determined total cost of the readmissions, and determined 30-day postsurgical SSI incidence for the prophylactic VAC group. RESULTS: Per the Wiseman scores, 9 limbs with postoperative complications were high risk and 3 limbs were moderate/high risk. Eleven limbs had a VAC placed at readmission with an average readmission cost of $8876.77. For the prophylactic group, 8 limbs were high risk with no observed postdischarge SSI in the first 30 days from surgery. The Wiseman scores showed close correlation between the retrospective high and moderate/high risk groups versus the prophylactic VAC group (31.5 ± 7.3 vs. 32 ± 5.5, P = 0.87). CONCLUSIONS: The Wiseman scores showed objective validation in the prognosis of anticipating groin wound breakdown. Our initial results suggest that prophylactic groin wound VAC placement for enhanced risk vascular surgery patients may proactively decrease wound morbidity, decrease readmission secondary to groin wound complications, and provide some cost benefit.

Staged retroperitoneal mesenteric revascularisation and aortobifemoral bypass after endovascular rescue for acute mesenteric ischaemia.

Visceral artery revascularisation through a retroperitoneal approach provides an infrequent yet viable, alternative means of managing mesenteric ischaemia in patients with previous abdominal operations. We present a unique case implementing this surgical approach in a 55-year-old man in which we performed a retroperitoneal aortobifemoral bypass with concomitant retrograde jump graft from the aortic prosthesis to the superior mesenteric artery (SMA) for bilateral lower extremity rest pain and chronic mesenteric ischaemia. Three months previously, the patient had presented with acute mesenteric ischaemia and colonic perforation. He underwent emergent celiac artery stenting followed by an exploratory laparotomy with total abdominal colectomy and diverting loop ileostomy. Given the patient's hostile abdomen, a retroperitoneal approach to SMA revascularisation was elected over a transabdominal approach during concomitant lower extremity revascularisation for critical limb ischaemia. We achieved an excellent technical result with resolution of limb ischaemia and abdominal symptoms.

Hybrid external iliac selective endarterectomy surgical technique and outcomes.

OBJECTIVE: Long or multisegmental external iliac-to-femoral arterial lesions treated by angioplasty and stenting have achieved disappointing results. Conventional, open approaches are often complicated by significant morbidity, and endovascular stenting alone typically requires additional outflow procedures. We hypothesized that a hybrid approach, combining endovascular techniques with remote selective external iliac endarterectomy, produces superior outcomes in terms of patency compared with stenting alone, with minimal associated morbidity. METHODS: We performed a retrospective review of all patients having undergone hybrid-based retrograde iliofemoral endarterectomy from 2010 to 2014 at St. Joseph Mercy in Ann Arbor, Michigan. Patient demographics, presenting complaints, operative details, and complications were analyzed. Postoperative patency was assessed by comparison of ankle-brachial index values and qualitative patient improvement. Data were analyzed by way of paired Student t-test with significance defined as P < .05. RESULTS: A total of 40 limbs were intervened upon on 33 patients. In 20 limbs, the procedure was performed for critical limb ischemia (rest pain, n = 9; tissue loss/gangrene, n = 11). By TransAtlantic Inter-Society Consensus II criteria, 83% of iliac lesions were class D. A more even distribution was noted in TransAtlantic Inter-Society Consensus II classification for femoral and popliteal disease. Seventeen percent of patients had one-vessel infrageniculate runoff. In 21 limbs (54%), external iliac artery (EIA) stenting was performed at the time of procedure, 18 (46%) had common iliac artery (CIA) stenting, and 7 (18%) had a bridging stent from the CIA to EIA. The modal EIA stent diameter was 10 mm (range, 8-10 mm), modal CIA stent diameter 8 mm (range, 7-9 mm). The preintervention ankle-brachial index was 0.45 ± 0.24 (n = 33 limbs) and significantly improved to 0.75 ± 0.27 (n = 29 limbs; P < .001). In addition, preintervention toe pressure of 34 ± 28 (n = 28 limbs) improved to 58 ± 26 (n = 23 limbs; P < .001). No intraoperative complications occurred, which necessitated abdominal or retroperitoneal exposure. Average follow-up after the intervention was 13 ± 14.6 months. One limb (3%) required an additional outflow bypass. The incidence of ipsilateral hypogastric occlusion increased from 35% to 55% postoperatively; however, no patients reported pelvic or buttock ischemia. One patient who had the procedure done bilaterally presented 655 days after the procedure with bilateral iliac artery thrombosis and underwent aortobifemoral bypass. No other patient needed subsequent primary assisted patency or additional infrainguinal revascularization. CONCLUSIONS: Hybrid-based external iliac and femoral endarterectomy provides a minimally invasive approach to EIA occlusive disease comparable with aortofemoral bypass. Dramatic inflow improvement was observed in our series, and the need for additional outflow revascularization was minimal. The procedure was deemed technically feasible and safe, with a low number of adverse sequela and excellent primary patency achieved more than 1 year after the intervention.

Proteomic Profiling of Early Chronic Pulmonary Hypertension: Evidence for Both Adaptive and Maladaptive Pathology.

BACKGROUND: The molecular mechanisms governing right atrial (RA) and ventricular (RV) hypertrophy and failure in chronic pulmonary hypertension (CPH) remain unclear. The purpose of this investigation was to characterize RA and RV protein changes in CPH and determine their adaptive versus maladaptive role on hypertrophic development. METHODS: Nine dogs underwent sternotomy and RA injection with 3 mg/kg dehydromonocrotaline (DMCT) to induce CPH (n=5) or sternotomy without DMCT (n=4). At 8-10 weeks, RA and RV proteomic analyses were completed after trypsinization of cut 2-D gel electrophoresis spots and peptide sequencing using mass spectrometry. RESULTS: In the RV, 13 protein spots were significantly altered with DMCT compared to Sham. Downregulated RV proteins included contractile elements: troponin T and C (-1.6 fold change), myosin regulatory light chain 2 (-1.9), cellular energetics modifier: fatty-acid binding protein (-1.5), and (3) ROS scavenger: superoxide dismutase 1 (-1.7). Conversely, beta-myosin heavy chain was upregulated (+1.7). In the RA, 22 proteins spots were altered including the following downregulated proteins contractile elements: tropomyosin 1 alpha chain (-1.9), cellular energetic proteins: ATP synthase (-1.5), fatty-acid binding protein (-2.5), and (3) polyubiquitin (-3.5). Crystallin alpha B (hypertrophy inhibitor) was upregulated in both the RV (+2.2) and RA (+2.6). CONCLUSIONS: In early stage hypertrophy there is adaptive upregulation of major RA and RV contractile substituents and attenuation of the hypertrophic response. However, there are multiple indices of maladaptive pathology including considerable cellular stress associated with aberrancy of actin machinery activity, decreased efficiency of energy utilization, and potentially decreased protein quality control.

Surgical management of abdominal aortic aneurysms: a lost art?

Endovascular repair of abdominal aneurysms has become the dominant treatment modality for infrarenal aneurysms. Initial reports showed a constant number of open repairs although there was a shift toward complicated juxtra-renal aneurysms. In the past several years, more aggressive endoluminal approaches and the introduction of fenestrated grafts have appeared to dilute the open aneurysm operating experience. Coupled with work hours restrictions and shorter training paradigms, opportunities for training residents in open repair of abdominal aneurysms are decreasing. We envision that future treatment of complicated aortic aneurysms will likely entail advanced fellowship training in open repair and referral of complicated abdominal aneurysms to tertiary care centers.

Importance of atrial surface area and refractory period in sustaining atrial fibrillation: testing the critical mass hypothesis.

OBJECTIVE: The critical mass hypothesis for atrial fibrillation (AF) was proposed in 1914; however, there have been few studies defining the relationship between atrial surface area and AF. This study evaluated the effect of tissue area and effective refractory period (ERP) on the probability of sustaining AF in an in vivo model. METHODS: Domestic pigs (n = 9) underwent median sternotomy. Epicardial activation maps were constructed from bipolar electrograms recorded from form-fitting electrode templates placed on the atria. Baseline ERPs were determined. ERP was lowered with a continuous infusion of acetylcholine (0.005-0.04 mg/Kg/min) until AF could be sustained after burst pacing. The atria were sequentially partitioned using bipolar radiofrequency ablation. ERPs were lowered using acetylcholine until AF could be sustained in each subdivision of atrial tissue. Each subdivision was further divided until AF was no longer inducible. At study completion, the heart was excised and the surface area of each section was measured. RESULTS: Over a range of ERPs from 75 to 250 ms, the probability of AF was correlated with increasing tissue area (range, 19.5-105 cm(2)) and decreasing ERP. Logistic regression analysis identified shorter ERP (P < .001) and larger area (P = .006) as factors predictive of an increased probability of sustained AF (area under the curve of the receiver-operator characteristic = 0.878). CONCLUSIONS: The probability of sustained AF was significantly associated with increasing tissue area and decreasing ERP. These data may lead to a greater understanding of the mechanism of AF and help to design better interventional procedures.

Differential calcium handling in two canine models of right ventricular pressure overload.

BACKGROUND: The purpose of this investigation was to characterize differential right atrial (RA) and ventricular (RV) molecular changes in Ca(2+)-handling proteins consequent to RV pressure overload and hypertrophy in two common, yet distinct models of pulmonary hypertension: dehydromonocrotaline (DMCT) toxicity and pulmonary artery (PA) banding. METHODS: A total of 18 dogs underwent sternotomy in four groups: (1) DMCT toxicity (n = 5), (2) mild PA banding over 10 wk to match the RV pressure rise with DMCT (n = 5); (3) progressive PA banding to generate severe RV overload (n = 4); and (4) sternotomy only (n = 4). RESULTS: In the right ventricle, with DMCT, there was no change in sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) or phospholamban (PLB), but we saw a trend toward down-regulation of phosphorylated PLB at serine-16 (p[Ser-16]PLB) (P = 0.07). Similarly, with mild PA banding, there was no change in SERCA or PLB, but p(Ser-16)PLB was down-regulated by 74% (P < 0.001). With severe PA banding, there was no change in PLB, but SERCA fell by 57% and p(Ser-16)PLB fell by 67% (P < 0.001). In the right atrium, with DMCT, there were no significant changes. With both mild and severe PA banding, p(Ser-16)PLB fell (P < 0.001), but SERCA and PLB did not change. CONCLUSIONS: Perturbations in Ca(2+)-handling proteins depend on the degree of RV pressure overload and the model used to mimic the RV effects of pulmonary hypertension. They are similar, but blunted, in the atrium compared with the ventricle.

Chronic performance of a novel radiofrequency ablation device on the beating heart: Limitations of conduction delay to assess transmurality.

OBJECTIVE: The creation of consistently transmural lesions with epicardial ablation on the beating heart has represented a significant challenge for current technology. This study examined the chronic performance of the AtriCure Coolrail device (AtriCure Inc, West Chester, Ohio), an internally cooled, bipolar radiofrequency ablation device designed for off-pump epicardial ablation. The study also examined the reliability of using acute intraoperative conduction delay to evaluate lesion integrity. METHODS: Seven swine underwent median sternotomy. The right atrial appendage and inferior vena cava were isolated with a bipolar radiofrequency clamp. Linear ablation lines were created between these structures with the AtriCure Coolrail. Paced activation maps were recorded with epicardial patch electrodes acutely before and after ablation and after keeping the animals alive for 4 weeks. The conduction time across the linear ablation was calculated from these maps. The lesions were histologically evaluated with trichrome staining. RESULTS: Only 76% of cross-sections of Coolrail lesions were transmural, and only 1 of 12 ablation lines was transmural in every cross-section examined. Mapping data were available in 5 of the animals. Significant conduction delay was present after the creation of each line of ablation acutely; however, after 4 weeks, conduction time returned to preablation values, demonstrating lack of transmurality. CONCLUSIONS: The AtriCure Coolrail failed to reliably create transmural lesions. Although the Coolrail was able to create acute conduction delay, its failure to transmurally ablate the atrial myocardium left gaps along the length of the lesion, which resulted in neither chronic conduction block nor delay across any line of ablation.

Outcomes of percutaneous endovascular intervention for type II endoleak with aneurysm expansion.

OBJECTIVE: Type II endoleak (T2EL) with aneurysm expansion is believed to place patients at risk for aneurysm-related mortality (ARM). Treatment with glue and/or coil embolization of the aneurysm sac, inferior mesenteric artery (IMA), and lumbar branches via translumbar or transarterial approaches has been utilized to ablate such endoleaks, and thus decrease ARM. We evaluated the midterm results of percutaneous endovascular treatment of T2EL with aneurysm expansion. METHODS: Single-institution, 5-year (January 2003 to August 2008) retrospective study of all endovascular interventions for T2EL with sac expansion. Blinded, independent review of all available pre- and post-T2EL intervention computed tomography (CT) scans was performed. Aneurysm sac maximal transverse diameters and aneurysm sac growth rates prior to and following T2EL intervention were analyzed. RESULTS: Forty-two patients (34 male, eight female; mean age, 75) underwent T2EL intervention at 26 ± 20 months after endovascular aneurysm repair (EVAR) and were subsequently followed for 23 ± 20 months. Seven out of 42 patients (17%) underwent repeat T2EL intervention. Interventions included 44 translumbar sac embolizations, and transcatheter embolizations of nine IMAs and seven lumbar/hypogastric arteries. Aneurysm diameter was 6.1 ± 1.6 cm at EVAR, 6.6 ± 1.5 cm at initial T2EL treatment, and 6.9 ± 1.7 cm at last follow-up. There were no significant differences in the rates of aneurysm sac growth pre- and post-T2EL treatment. At last follow-up imaging, recurrent or persistent T2EL was noted in 72% of patients. Of 42 patients, nine (21%) received operative endoluminal correction of occult type I or type III endoleaks that were diagnosed during the T2EL angiographic intervention. There were no aneurysm ruptures or ARMs during follow-up; overall mortality for the 5-year study period was 24%. CONCLUSIONS: In this series, percutaneous endovascular intervention for type II endoleak with aneurysm sac growth does not appear to alter the rate of aneurysm sac growth, and the majority of patients display persistent/recurrent endoleak. However, diagnostic angiographic evaluation may reveal unexpected type I and III endoleaks and is therefore recommended for all patients with T2EL and sac growth. While coil and glue embolization of aneurysm sac and selected branch vessels does not appear to yield benefit in our series, the diagnosis and subsequent definitive treatment of previously occult type I and III endoleaks may explain the absence of delayed rupture and ARM in our series.