Miles Conrad

Mycotic Pseudoaneurysms Due to Injection Drug Use: A Ten-Year Experience

BACKGROUND Arterial injury and infection due to repetitive injection drug use can result in mycotic pseudoaneurysm predisposing to hemorrhage, distal embolism, limb loss, and death. We hypothesized that debridement of the infected artery, followed by immediate vascular reconstruction, results in successful limb salvage in these patients. METHODS The setting was a county hospital. A retrospective review of all patients diagnosed with lower extremity pseudoaneurysms by the Departments of Surgery and Radiology between 2000 and 2009 was conducted. Outcome measures were patient characteristics, site(s) of lesion, type and results of imaging, type of operation, length of hospital stay, and complications. RESULTS Sixteen patients had 17 pseudoaneurysms. One of the patients had two mycotic pseudoaneurysms in the same region separated by a period of 10 months. Culture of the wall of the first pseudoaneurysm was not performed. The second pseudoaneurysm was culture positive. The 15 remaining mycotic pseudoaneurysms were all culture positive. Nine patients were men, and the median age of the patient group was 37 years. Common femoral pseudoaneurysms were the most frequent (76%). Symptoms included swelling (94%), pain (82%), and erythema (75.6%). A rapidly expanding pulsatile expansile mass was present in four of the patients. Computed tomography and percutaneous angiography were done in seven and four of the patients, respectively, and were diagnostic in all cases studied. Resection and reconstruction with autologous vein was the most common procedure (seven), followed by cadaveric grafting (four), synthetic grafting (two), ligation (two), and primary repair (two). Muscle flaps were used in 76.5% of the cases. Complications included anastomotic dehiscence (n = 3), acute thrombosis (n = 1), ischemia (n = 1), abscess (n = 1), and compartment syndrome (n = 1). Three of these patients required a second vascular reconstruction. One patient ultimately required an amputation. No postoperative deaths occurred. Methicillin-resistant Staphylococcus aureus was cultured from 13 of the 16 arterial walls. CONCLUSION Methicillin-resistant Staphylococcus aureus is the predominant organism causing mycotic aneurysms of the common and superficial femoral arteries owing to injection drug use at San Francisco General Hospital. Wide debridement of the infected artery and reconstruction with an in-line reversed saphenous vein or cryopreserved vascular allograft is a safe and effective method of treatment. Long-term follow-up studies are needed to determine the durability of this method of treatment.

Intraprocedural Safety and Technical Success of the MVP Micro Vascular Plug for Embolization of Pulmonary Arteriovenous Malformations

This case series describes early experience, intraprocedural safety, and technical success of the MVP Micro Vascular Plug (MVP; Covidien, Irvine, California) for embolization of 20 pulmonary arteriovenous malformations (PAVMs) using 23 plugs in seven patients with hereditary hemorrhagic telangiectasia. There was no device migration, and all devices were successfully detached electrolytically. Immediate cessation of flow through the feeding artery was achieved in 21 of 23 (91%) deployments. There was one minor complication. This series demonstrates the MVP to be safe and technically successful in the treatment of PAVMs.

Bartonella quintana Aortitis in a Man with AIDS, Diagnosed by Needle Biopsy and 16S rRNA Gene Amplification

ABSTRACT A man with newly diagnosed AIDS presented with months of back pain and fever. Computed tomography (CT) results demonstrated aortitis with periaortic tissue thickening. DNA amplification of biopsy tissue revealed Bartonella quintana, and Bartonella serologies were subsequently noted to be positive. The patient improved with prolonged doxycycline and rifabutin treatment. This case illustrates how molecular techniques are increasingly important in diagnosing Bartonella infections.

Accuracy of a polarographic electrode at high oxygen concentrations.

Oxygen plays a central role in wound healing. It is required for angiogenesis, collagen deposition, epithelization, and superoxide production for intracellular bacterial killing. Wound oxygen concentration depends upon the complex interactions of blood perfusion, intercapillary distance, local oxygen consumption, arterial oxygen concentration, and oxyhemoglobin dissociation conditions. Accurate determination of wound p02 during hyperbaric oxygen (HBO) treatment requires direct measurement. Transport of oxygen to the hypoxic center of a wound, or to a wound with impaired perfusion, is often only possible with HBO exposure. Several studies have shown that HBO promotes wound healing, especially in hypoxic wounds.

Pilot Study of the Safety and Efficacy of Gallbladder Cryoablation in a Porcine Model: Midterm Results

PURPOSE To investigate the midterm safety and efficacy of computed tomography (CT)-guided percutaneous gallbladder cryoablation in swine. MATERIALS AND METHODS Three swine underwent gallbladder cryoablation. Cryoprobes were positioned percutaneously at the gallbladder margins or within the gallbladder lumen under CT guidance. Two freeze/thaw cycles were performed. One animal was euthanized on postprocedure day 4 as a result of hematemesis unrelated to the ablation. The other 2 animals were euthanized at postprocedure days 30 and 48, respectively. The gallbladder and bile ducts were resected and examined microscopically. RESULTS Gallbladder cryoablation was completed with freeze/thaw cycle durations of 7.5-10 minutes (mean, 9.4 min ± 1.3) and ablation margins of 5.8-11.5 mm (mean, 7.8 mm ± 1.9). No nontarget ablation was observed. Laboratory values at postprocedure day 4 and the time of euthanasia were within normal limits. Two of 3 animals thrived and exhibited appropriate activity and weight gain. Contrast-enhanced CT immediately before euthanasia demonstrated delayed linear enhancement of the gallbladder wall. Gross inspection at autopsy revealed fibrotic-appearing gallbladders. Cholecystography revealed no communication to the biliary tree. Histologic examination demonstrated complete gallbladder wall fibrosis. Autopsy of the animal euthanized on day 4 revealed a gastric mucosal ulcer distant from the ablation site with no gastric serosal injury. CONCLUSIONS Gallbladder cryoablation is a promising alternative to surgical cholecystectomy, with complete transmural gallbladder wall fibrosis and cystic duct occlusion seen at 30 and 48 days in swine. Further studies are required to establish procedural safety and long-term efficacy.

Endovascular Biopsy and Endothelial Cell Gene Expression Analysis of Dialysis Arteriovenous Fistulas: A Feasibility Study

PURPOSE To demonstrate feasibility of endothelial cell (EC) biopsy from dialysis arteriovenous fistulas (AVFs) with the use of guidewires and to characterize gene expression differences between ECs from stenotic and nonstenotic outflow vein segments. MATERIALS AND METHODS Nine consecutive patients undergoing fistulography for AVF dysfunction from June to August 2016 were enrolled. ECs were biopsied with the use of guidewires from venous outflow stenoses and control outflow veins central to the stenoses. ECs were sorted with the use of flow cytometry, and the Fluidigm Biomark HD system was used for single-cell quantitative polymerase chain reaction (qPCR) analysis of gene expression. Forty-eight genes were assessed and were selected based on different cellular functions and previous literature. Linear mixed models (LMMs) were used to identify differential gene expression between the groups, and self-organizing maps (SOMs) were used to identify cell clusters based on gene coexpression profiles. RESULTS A total of 219 and 213 ECs were sampled from venous outflow stenoses and control vein segments, respectively. There were no immediate biopsy-related complications. Forty-eight cells per patient were sorted for qPCR analysis. LMM identified 7 genes with different levels of expression at stenotic segments (P < .05), including AGTR-2, HMOX-2, MTHFR, SERPINC-1, SERPINE-1, SMAD-4, and VWF. SOM analysis identified 4 cell clusters with unique gene expression profiles, each containing stenotic and control ECs. CONCLUSIONS EC biopsy from dialysis AVFs with the use of guidewires is feasible. Gene expression data suggest that genes involved in multiple cellular functions are dysregulated in stenotic areas. SOMs identified 4 unique clusters of cells, indicating EC phenotypic heterogeneity in outflow veins.

Percutaneous embolization of post traumatic splenic pseudoaneurysm

Management of splenic pseudoaneurysms in hemodynamically stable patients has shifted toward nonoperative management, including watchful waiting and endovascular embolization. Standard of treatment does not include percutaneous embolization for splenic pseudoaneurysm repair. In this case report, we document a successful percutaneous embolization of a post traumatic splenic pseudoaneurysm with thrombin. Percutaneous embolization of splenic pseudoaneurysms can be considered a viable technique in patients who fail endovascular embolization or have lesions inaccessible to endovascular repair.

Solitary fibrous tumor in the abdomen and pelvis: A case series with radiological findings and treatment recommendations☆

This study presents the radiological findings of seven cases of solitary fibrous tumor (SFT) in the abdomen and pelvis. A retrospective search of the pathology database at our institution was performed to identify cases of SFT in the abdomen and pelvis. After identifying seven cases, cross-sectional imaging was reviewed and characterized. We conclude that SFTs in the abdomen and pelvis should be considered with well-defined, circular, hypervascular masses. Pelvic SFTs should be considered with homogenous, avidly enhancing masses. Embolization of feeding arteries can allow safe surgical resection or biopsy, but embolization appears to not offer a definitive therapy.

Interest in Interventional Radiology at Different Stages of Training: Possible Implications for the New Integrated Interventional Radiology Residency

PURPOSE Integrated interventional radiology (IR) residencies recently underwent their second year in the match, the first year of which involved only a limited number of programs. Now that students can choose to enter IR directly, student perceptions of IR vs diagnostic radiology (DR) are of paramount importance. METHODS We surveyed first- through fourth-year medical students and radiology residents regarding interest in IR vs DR. RESULTS Students considering a radiological career expressed more interest in IR than DR. Conversely, residents expressed more interest in DR. CONCLUSIONS Medical student advisors and IR programs should continue to anticipate a high number of applications for integrated IR positions.

Reproductive and gynecologic health after uterine artery embolization for postabortion hemorrhage.

a Division of Gynecology, Department of Obstetrics, Gynecology and Reproductive Science, University of California San Francisco, CA, USA b Division of San Francisco General Hospital, Department of Obstetrics, Gynecology, and Reproductive Science, University of California San Francisco, CA, USA c Tulane University School of Medicine, New Orleans, LA, USA d Department of Interventional Radiology, University of California San Francisco, CA, USA