Asymptomatic portal vein aneurysms: To treat, or not to treat?

Background Portal vein aneurysms are rare dilations in the portal venous system, for which the etiology and pathophysiological consequences are poorly understood. Method We reviewed the existing literature as well as present a unique anecdotal case of a patient presenting with a very large portal vein aneurysm that was successfully managed conservatively and non-operatively without anticoagulation, with close follow-up and routine surveillance. Result The rising prevalence of abdominal imaging in clinical practice has increased rates of portal vein aneurysm detection. While asymptomatic aneurysms less than 3 cm can be clinically observed, surgical intervention may be necessary in large asymptomatic aneurysms (>3 cm) with or without thrombus, or small aneurysms with evidence of evolving mural thrombus formation on imaging. Conclusion Portal vein aneurysms present a diagnostic challenge for any surgeon, and the goal for surgical therapy is based on repairing the portal vein aneurysm, and if portal hypertension is present decompressing via surgically constructed shunts.

Contemporary comparison of aortofemoral bypass to alternative inflow procedures in the Veteran population.

OBJECTIVE: Multiple vascular inflow reconstruction options exist for claudication, including aortofemoral bypass (AFB) and alternative inflow procedures (AIPs) such as femoral reconstruction with iliac stents, and femoral-femoral, iliofemoral, and axillofemoral bypass. Contemporary multi-institution comparison of these techniques is lacking. METHODS: The Veterans Affairs Surgical Quality Improvement Project (VASQIP) national database (2005-2013) was used to compare AFB vs AIP in a propensity-matched analysis. Primary outcome was mortality at 30 and 90 days. Secondary outcomes included rates of postoperative complications. Multivariable regression assessed the adjusted effect of inflow procedure type on mortality. RESULTS: A matched cohort of 748 claudicant patients (373 AFB, 375 AIP) was identified. The AFB and AIP groups had similar mean age (59.9 vs 60.8 years; P = .30), gender (P = .51), race (P = .52), recent smoking (79.1% vs 76.5%; P = .43), history of coronary artery disease (14.8% vs 14.7%; P > .99), chronic obstructive pulmonary disease (18.8% vs 18.4%; P = .92), renal insufficiency (5.9% vs 6.1%; P > .99), and diabetes (22% vs 20%; P = .53), and American Society of Anesthesiologists Physical Status Classification (P = .41). The AFB group had longer mean operative time (4.9 vs 3.5 hours; P < .0001), more senior resident assistants (72.4% vs 61.1%; P < .0001), and greater mean red blood cell transfusion (1.1 vs 0.12 units; P < .0001). AFB and AIP had similar rates of outflow bypass (1.9% vs 1.3%; P = .58) and outflow endovascular interventions (0.54% vs 1.6%; P = .29). AFB trended toward a higher rate of mortality at 30 days postoperatively (2.7% vs 0.8%; P = .06), but by 90 days, the crude mortality rates were similar for the two (2.9% vs 2.1%; P = .5). AFB had higher rates of pneumonia (5.9% vs 0.8%; P < .001), deep vein thrombosis/pulmonary embolism (1.3% vs 0%; P = .03), postoperative transfusion (2.7% vs 0.53%; P = .02), and urinary tract infection (3.5% vs 0.8%; P = .01), but similar rates of myocardial infarction (1.6% vs 0.8%; P = .34), stroke (0.8% vs 0%; P = .12), wound complications (13.1% vs 12.8%; P = .91), renal failure (1.1% vs 0.3%; P = .22), graft failure (1.3% vs 1.1%; P = .75), and return to the operating room (12.9% vs 9.6%; P = .17). Multivariable analysis showed AFB was not independently associated with mortality (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.1-3.0). Significant factors included age (OR, 1.2; 95% CI, 1.1-1.4), postoperative renal insufficiency (OR, 2.5; 95% CI, 1.6-4.0), and unplanned reintubation (OR, 35.5; 95% CI, 3.1-399). CONCLUSIONS: For claudicant patients with inflow disease, AFB has higher rates of 30-day complications and a trend toward higher mortality; however by 90 days postoperatively, the two procedure types have similar rates of mortality.

Impact of coexisting aneurysms on open revascularization for aortoiliac occlusive disease.

OBJECTIVE: National data evaluating outcomes for occlusive abdominal aortic reconstructions are well described. The relative effect of operative indication as well as the presence of concomitant abdominal aortic aneurysm (AAA) on in-hospital mortality is not well defined. METHODS: The Nationwide Inpatient Sample was queried to identify patients who underwent open aortic surgery (2003-2010). Indication for surgery was classified by International Classification of Diseases, Ninth Revision diagnostic codes to identify isolated occlusive indications as well as combined occlusive disease and AAA. Primary outcome was in-hospital mortality. Secondary outcomes were complications and discharge disposition. RESULTS: Overall, 56,374 underwent aortic reconstruction, 48,591 for occlusive disease (86.2%) and 7783 for combined occlusive disease with AAA (13.8%). Intermittent claudication was the most common indication for intervention (60.9%), whereas 39.7% underwent intervention for critical limb ischemia (22.2% rest pain, 17.6% gangrene). Patients with intermittent claudication had more concomitant AAAs (17.3%) than did patients with critical limb ischemia (8.4%). The baseline characteristics for those with occlusive disease and combined occlusive with AAA disease were similar in terms of obesity (4.8% vs 4.2%; P = .27) and congestive heart failure (6.6% vs 6.3%; P = .65) but differed by age (62.2 years vs 68.4 years; P < .0001) and hypertension (65.4% vs 69.1%; P = .005). Patients with combined occlusive and AAA disease had higher mortality than those with occlusive disease alone (3.9% vs 2.7%; P = .01). On multivariable regression, factors associated with in-hospital mortality included gangrene with AAA compared with gangrene alone (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.6-4.7; P < .0002), age >65 years age (OR, 3.1; 95% CI, 2.4-4.1; P < .0001), renal failure (OR, 2.7; 95% CI, 1.9-3.8; P < .0001), and concurrent lower extremity revascularization (OR, 1.3; 95% CI, 1.1-1.7; P < .02). CONCLUSIONS: Intermittent claudication or critical limb ischemia with concomitant AAA carries a higher mortality than intermittent claudication or critical limb ischemia alone, especially in older patients with gangrene requiring revascularization and renal insufficiency. Preoperative risk stratification strategies should focus on the indication for surgery as well as the presence of concomitant AAA.

Perioperative outcomes of elective inflow revascularization for lower extremity claudication in the American College of Surgeons National Surgical Quality Improvement Program database.

BACKGROUND: We compared the early postoperative morbidity and mortality rates of contemporary aortofemoral bypass (AFB) and other inflow procedures for claudication. METHODS: We identified 1974 claudicants who underwent elective AFB (n = 566) or non-AFB (nonaortofemoral bypass [NAFB]; n = 1408) inflow reconstruction using the ACS-NSQIP database (2005 to 2012). Stent placement was not routinely captured. In propensity score-matched cohorts, we analyzed the association between type of inflow surgery and 30-day postoperative outcomes. RESULTS: Among 824 propensity score-matched patients (AFB, n = 412; NAFB, n = 412), the 30-day mortality rate was 2.7% for AFB and .0% for NAFB (P = .0008). NAFB conferred significantly lower rates of major cardiac (.2% vs 2.4%, P = .0063), respiratory (.7% vs 10.9%, P < .0001), renal (.2% vs 1.9%, P = .0380), and septic (.5% vs 3.6%, P = .0014) complications, and fewer returns to the operating room (4.6% vs 9.9%, P = .0032), compared with AFB. Rates of major venous thrombosis, wound complications, peripheral nerve injury, and graft failure were similar between the groups. CONCLUSIONS: This study reports a higher contemporary short-term complication rate with AFB compared to alternative inflow revascularization, against which future study of long-term durability may be weighed.

Technical tips for successful outcomes using adjunctive procedures during endovascular aortic aneurysm repair.

The inability to obtain proximal or distal seal continues to remain one of the main challenges of endovascular aneurysm repair. This is particularly relevant when endografts are used in patients with unsuitable proximal or distal landing zones. A variety of techniques can be used to achieve a seal in these difficult situations. Two specific techniques that can help intraoperatively to resolve the lack of adequate graft to aortic wall opposition are discussed in this article. These include the use of Palmaz stents for proximal seal and hypogastric snorkel for distal seal with internal iliac flow preservation.

Acute expansion of a hospital-acquired methicillin-resistant Staphylococcus aureus-infected abdominal aortic aneurysm.

Infected aortic aneurysms (IAAs) are rare but can have devastating outcomes, particularly if diagnosis and treatment are delayed. The incidence of IAA is between 0.65% and 2% of all aortic aneurysms. The disease has a poor prognosis because these aneurysms have an increased tendency to grow rapidly and to rupture, and patients often have severe comorbidities and coexisting sepsis. Typical microorganisms associated with IAA are Salmonella, Streptococci, and Staphylococcus aureus. Methicillin-resistant Staphylococcus aureus (MRSA) continues to emerge as a cause of serious infections, but its association with IAA is extremely rare. We present a rare case of infected abdominal aortic aneurysm caused by hospital-acquired (HA) MRSA. This case adds another presentation to the clinical spectrum of HA MRSA infections, and it highlights the problems encountered in the choice of the therapy of serious HA or health care-acquired infections in an era of increasing MRSA infections. We will discuss the clinical spectrum of HA MRSA infections as well as the problems encountered in the management of IAA, and will review the relevant literature.

Results of external iliac artery reconstruction in avid cyclists.

OBJECTIVE: We report the midterm results of external iliac artery reconstruction in 25 high-performance cyclists. METHODS: Cyclists undergoing arterial reconstruction for symptomatic external iliac arteriopathy at a single institution between October 2004 and August 2010 were identified. With Institutional Review Board approval, data were collected from medical record review and telephone interview. Results were analyzed with χ(2) or independent t-test. RESULTS: Twenty-five patients (31 limbs) underwent operation, which included arterial reconstruction with or without inguinal ligament release. The average patient age at operation was 43.8 ± 5.0 for graft and 35.1 ± 1.9 for patch (P = .08). The average time from competitive cycling until operation was 18.2 ± 5.8 years for graft and 20.0 ± 2.5 for patch repairs (NS). Patients included 14 males and 11 females. There were 23 unilateral and four bilateral arterial reconstructions, including 26 patch angioplasties for localized disease and five interposition grafts for extensive disease; three patients underwent contralateral reconstruction as a separate procedure. Concomitant ipsilateral inguinal ligament release was performed in 25 patients (28 limbs), with contralateral release done in 12 patients (12 limbs). Three patients with isolated ligament release required subsequent arterial intervention. Follow-up averaged 32 months (range, 2-74). Primary patency for all reconstructions was 100%; the four reoperations (five limbs; one bilateral) were for symptom recurrence, two postgraft and two postangioplasty. Three reoperations were for recurrent intimal hyperplasia, one for disease distal to the anastomosis, and one for concomitant atherosclerotic disease. Based on available data, postexercise ankle-brachial indices were improved in 18 of 23 limbs. Seventeen patients completed questions regarding satisfaction: 10 were satisfied or very satisfied (zero graft, 10 patch; P = .25), while four were unsatisfied (three graft, two patch; P = .017, including one patient with both a patch and graft repair). All 20 patients for whom follow-up data were available are still cycling, 10 competitively. Two of the four reoperated patients were unsatisfied; all four are still cycling, one competitively. CONCLUSIONS: External iliac arteriopathy is a disease of prolonged, sustained, and repetitive trauma. Patch angioplasty yields a low rate of reoperation, more satisfied patients, return to competitive activity, and improvement in postexercise ankle-brachial indices. Interposition grafting is associated with slightly older patients, more extensive disease, and less satisfying results. Intimal hyperplasia is the most frequent complication necessitating reoperation. Both the decision to pursue arterial reconstruction and patient expectations must be tempered by the pattern of disease and the potential for unsatisfactory results.

Imaging evaluation of flow limitations in the iliac arteries in endurance athletes: diagnosis and treatment follow-up.

OBJECTIVE: The purpose of this article is to review the role of imaging in the diagnosis, treatment, and follow-up of patients with sport-related flow limitations in the iliac arteries. CONCLUSION: Endurance athletes can develop flow restriction during exercise because of endofibrosis or kinking of the iliac arteries. Knowledge of this entity and the use of appropriate imaging techniques are crucial for diagnosis. Imaging plays an important role in the assessment of the underlying lesion and its location as well as in posttreatment follow-up.

Single-incision external iliac artery endarterectomy and patch angioplasty.

An isolated external iliac artery chronic total occlusion is currently treated either with subintimal percutaneous transluminal angioplasty and stent or with a bypass. This article describes a new application of an old technique, endarterectomy and patch angioplasty, performed on the external iliac artery through a single flank incision. This novel approach can provide lasting patency with a low risk of complications. We present four cases and a review of the literature on the other available treatment options. This minimally invasive technique may provide a viable alternative that can be used alone or in combination with other open or endovascular techniques and can be applied in cases of groin sepsis.

The incidence of microemboli to the brain is less with endarterectomy than with percutaneous revascularization with distal filters or flow reversal.

BACKGROUND: Current data suggest microembolization to the brain may result in long-term cognitive dysfunction despite the absence of immediate clinically obvious cerebrovascular events. We reviewed a series of patients treated electively with carotid endarterectomy (CEA), carotid artery stenting (CAS) with distal filters, and carotid stenting with flow reversal (FRS) monitored continuously with transcranial Doppler scan (TCD) during the procedure to detect microembolization rates. METHODS: TCD insonation of the M1 segment of the middle cerebral artery was conducted during 42 procedures (15 CEA, 20 CAS, and 7 FRS) in 41 patients seen at an academic center. One patient had staged bilateral CEA. Ipsilateral microembolic signals (MESs) were divided into three phases: preprotection phase (until internal carotid artery [ICA] cross-shunted or clamped if no shunt was used, filter deployed, or flow reversal established), protection phase (until clamp/shunt was removed, filter removed, or antegrade flow re-established), and postprotection phase (after clamp/shunt was removed, filter removed, or antegrade flow re-established). Descriptive statistics are reported as mean ± SE for continuous variables and N (%) for categorical variables. Differences in ipsilateral emboli counts based on cerebral protection strategy were assessed using nonparametric methods. RESULTS: TCD insonation and procedural success were obtained in 33 procedures (79%; 14 CEA, 14 CAS, and 5 FRS). Highest ipsilateral MESs were observed for CAS (319.3 ± 110.3), followed by FRS (184.2 ± 110.5), and CEA (15.3 ± 22.0). Pairwise comparisons revealed significantly higher ipsilateral MESs with both FRS and CAS when compared to CEA (P = .007 for FRS and P < .001 for CAS vs CEA, respectively), whereas the difference in MESs between FRS and CAS was not significant (P = .053). Periods of maximum embolization were postprotection phase for CEA, protection phase for CAS, and preprotection phase for FRS. Preprotection MESs were frequently observed during both CAS and FRS (20.4% and 63.3% of total MESs across all phases, respectively), and the primary difference between these two methods seemed to be related to lower MESs during the protection phase with FRS. CONCLUSION: CEA is associated with lower rates of microembolization compared with carotid stenting. Flow reversal may represent a procedural modification with potential to reduce microembolization during carotid stenting; further investigation is warranted to determine the relationship between cerebral protection strategies and outcomes associated with carotid stenting.

Incidence of and outcomes after misaligned deployment of the talent thoracic stent graft system.

OBJECTIVE: Various types of device-specific adverse events can occur during deployment of thoracic stent grafts due to the high flow rate and severe aortic angulation that is often encountered in the thoracic aorta. This study assessed the incidence, etiology, and overall effect of misaligned deployment of the Talent Thoracic Stent Graft (TSG) System. Techniques to predict and avoid this complication are discussed. METHODS: Data collection included pivotal-trial follow-up, direct surveys of centers inside and outside the United States and principal investigators, a targeted literature search, and review of complaint files. Misaligned deployment was considered to occur when the proximal covered or uncovered stent apices of a thoracic stent graft folded back on itself and remained nonparallel to the wall of the aorta after deployment had been completed. RESULTS: Of about 20,305 deployments to date of the Talent TSG, 24 misaligned deployments were identified for an incidence of 0.1%. Nineteen (79%) events occurred during treatment of degenerative aneurysms or penetrating ulcers, four (17%) during treatment of dissections, and the underlying pathology could not be determined for one patient. The misalignment was noted at the proximal end of the stent graft in 15 patients (63%), and the other 9 events (37%) occurred at the graft overlap junction. Two events were treated intraoperatively, with a second overlapping device placed in one patient and a snare used to reposition the proximal stent in another. Adverse clinical events occurred in three patients and included a persistent type I endoleak, continued false lumen perfusion in a patient with dissection, and delayed retrograde type A dissection in a patient undergoing total arch repair. No intraoperative contrast extravasation or computed tomography evidence of perforation was noted. There were no perioperative deaths or cerebrovascular events, with one report of paraplegia among the 24 patients in this series. CONCLUSION: Misaligned deployment is an unusual phenomenon that tends to occur in the context of certain well-defined anatomic conditions in the thoracic aorta. To date, most of these events have not led to significant adverse sequelae. However, careful patient selection, periprocedural imaging, and case planning can help to identify anatomies in which misaligned opening is likely to occur, allowing physicians to avoid this complication.

Down-regulation of BCRP/ABCG2 in colorectal and cervical cancer.

Expression of Breast Cancer Resistance Protein (BCRP/ABCG2) in tumor cells is associated with resistance to multiple chemotherapeutic agents. BCRP also protects against phototoxicity by mediating the efflux of protoporphyrins from cells. However, chemotherapy and photodynamic therapy are effective treatment options for cancer. Furthermore, protoporphyrins are essential, in the form of heme, for the synthesis of nitric oxide, over-production of which is associated with cancer. This raises the question as to whether the expression of this transporter is altered in cancer. To address this question, we investigated the expression of BCRP in colorectal cancer and cervical cancer. Paired normal and cancer tissues from colectomy specimens were used for the analysis of BCRP mRNA by RT-PCR and Northern blot. BCRP was analyzed by immunohistochemistry/immunofluorescence. Similar studies were also done with specimens of normal cervix and cancer cervix. A commercial dot blot was probed to quantify the expression of BCRP in paired normal and cancer cDNA samples from 154 patients with tumors in 19 different tissues. BCRP mRNA was present in normal colorectal tissue and showed a 6-fold decrease in cancer. BCRP was abundant in the normal colon and showed a decrease in colon cancer. The down-regulation of BCRP mRNA and protein was also evident in cervical cancer. There was also a decrease in BCRP mRNA in cancer in 12 of the 19 different tissues collected from 154 patients. These data show that cancer-associated down-regulation of BCRP is likely to be a common phenomenon in several tissues. Decreased expression of BCRP may have a role in tumorigenesis by allowing accumulation of genotoxins and over-production of nitric oxide.

Up-regulation of the amino acid transporter ATB(0,+) (SLC6A14) in carcinoma of the cervix.

OBJECTIVE: ATB(0,+) is an energy-coupled transporter for arginine and amino acid-based prodrugs. The objective of the study was to examine the expression of this transporter in cervical cancer. METHODS: Specimens of normal ectocervical mucosa and cervical squamous cell carcinoma were used for determination of ATB(0,+) mRNA levels by RT-PCR. A commercial dot blot of paired normal cervix and cervical cancer cDNA was also used to quantify ATB(0,+) mRNA. ATB(0,+) mRNA and protein in tissue sections were analyzed by in situ hybridization and immunohistochemistry/immunofluorescence. RESULTS: ATB(0,+) mRNA increased 5.6-fold (P < 0.0004) in cervical cancer compared to normal cervix. This was associated with a parallel increase in ATB(0,+) protein. CONCLUSIONS: Expression of ATB(0,+) is minimal in normal cervix and is up-regulated in cervical cancer. The up-regulation of this highly concentrative transporter for arginine and prodrugs in cervical cancer has significant clinical and therapeutic relevance.

An anti-tumor role for cGMP-dependent protein kinase.

This study compared Type-1 cGMP-dependent protein kinase (PKG) expression in normal and tumor tissues and examined PKG function in tumor growth. Studies with a cDNA array revealed that PKG expression was reduced in many tumors compared to respective normal tissue. This decrease in PKG expression was confirmed using quantitative RT-PCR and western blotting of matched colon specimens from normal epithelium and tumor tissue, and also in colon derived cell lines where luciferase reporter analysis revealed that the decreased expression occurred at the transcriptional level. Using SW620 colon carcinoma cells engineered for inducible expression of PKG1beta, it was found that exogenous PKG1beta lead to decreased tumor growth and invasiveness in nude mouse xenografts.

SLC5A8 (SMCT1)-mediated transport of butyrate forms the basis for the tumor suppressive function of the transporter.

The identification of SLC5A8 as a tumor suppressor gene in colorectal cancer marks, for the first time, the association of a plasma membrane transporter with tumor suppressive properties. The subsequent establishment of the functional identity of SLC5A8 as a Na+-coupled transporter for short-chain monocarboxylates provides a mechanism for the tumor suppressive function of the transporter. Butyrate, a substrate for the transporter, is a histone deacetylase inhibitor and protective against colorectal cancer. This fatty acid is produced in the colonic lumen by bacterial fermentation of dietary fiber. SLC5A8 mediates the concentrative entry of butyrate from the lumen into colonocytes. Consequently, the transport function of SLC5A8 has the ability to influence the acetylation status of histones and hence gene expression in colonocytes. The ability of SLC5A8 to deliver butyrate into colonic epithelial cells most likely underlies the tumor suppressive role of this transporter.

Upregulation of the amino acid transporter ATB0,+ (SLC6A14) in colorectal cancer and metastasis in humans.

ATB(0,+) (SLC6A14) is a Na(+)/Cl(-)-coupled arginine transporter expressed at low levels in normal colon. Arginine is an essential amino acid for tumor cells. Arginine is also the substrate for nitric oxide synthases (NOSs). Since arginine and arginine-derived nitric oxide (NO) play a critical role in cancer, we examined the expression of ATB(0,+) in colorectal cancer. Paired normal and cancer tissues from colectomy specimens of 10 patients with colorectal cancer and from the liver tissue of one patient with hepatic metastasis from a colonic primary were used for the analysis of the levels of ATB(0,+) mRNA, inducible NOS (iNOS) mRNA and the corresponding proteins. Tissues samples from the colon, liver, and lymph nodes of an additional patient with metastatic colon cancer were analyzed for ATB(0,+) protein alone. We also examined the levels of nitrotyrosylated proteins. The ATB(0,+) mRNA increased 22.9+/-3.0-fold in colorectal cancer compared to normal tissue and the increase was evident in each of the 10 cases examined. iNOS mRNA increased 5.2+/-1.1-fold in cancer specimens. The changes in mRNA levels were associated with an increase in ATB(0,+), iNOS, and nitrotyrosylated proteins. The increased expression of ATB(0,+) and iNOS was also demonstrated in liver and lymph node specimens with metastases from colonic primaries. This study strongly suggests that the upregulation of ATB(0,+) may have a pathogenic role in colorectal cancer. Since ATB(0,+) is a versatile transporter not only for arginine but also for several drugs including NOS inhibitors, these findings have significant clinical and therapeutic relevance.