Eric Wellons

Evolving indications for and early results of carotid artery stenting

BACKGROUNDnWhile carotid endarterectomy continues to be the gold standard of treatment for most patients with significant carotid artery disease, there are cases where lesion or anatomy-related factors create situations less than ideal for conventional surgery. Other therapeutic modalities, such as endoluminal stenting, may represent reasonable options for such patients.nnnMETHODSnThirty-three patients with 70% or greater internal carotid artery lesions were treated by endovascular stent placement from July 1994 through June 1996. Indications included transient ischemic attacks in 20 and previous stroke in 4; and 9 were asymptomatic.nnnRESULTnStents were placed successfully in all instances. Mortality and stroke rates were zero. All patients remained asymptomatic during follow-up (mean 8 months), and stent patency by duplex ultrasound has been 100%. A single instance of intrastent restenosis has been observed.nnnCONCLUSIONSnEndoluminal stenting is an investigational technique of unproven efficacy and long-term durability. Yet it appears technically feasible, and possibly reasonable, as an alternate option for cases unfavorable for standard surgery.

Bedside intravascular ultrasound-guided vena cava filter placement☆

OBJECTIVEnSeveral reports have demonstrated the efficacy of inferior vena cava filter (IVCF) placement with intravascular ultrasound guidance (IVUS). The majority of these procedures,however, have been done in concert with contrast venography and/or fluoroscopic guidance. The purpose of this report was to evaluate the potential for bedside IVCF placement with real-time IVUS guidance only.nnnDESIGN OF STUDYnIn a phase I trial, 10 patients underwent IVUS interrogation of the IVC for diameter measurements and localization of the renal veins. Contrast venography verified the IVUS findings prior to filter deployment. In a phase II trial, another 35 patients underwent intensive care unit bedside placement of an IVC filter with only real time IVUS guidance using a double puncture technique in the same femoral vein. All patients underwent color-flow ultrasonography of the femoral veins after filter placement to rule out post procedure femoral vein thrombosis and plain radiographs of the abdomen to identify filter location.nnnRESULTSnIn the phase I trial, all filters were placed within 15 mm of the most inferior renal vein identified by IVUS. There were no complications, and successful filter placement was verified by contrast venography. In phase II, 33 IVCFs were placed without complications at approximately the L2 level by plain radiograph. One patient had an IVCF deployed in the common iliac vein, which necessitated placement of an uneventful second IVCF at the infrarenal location by IVUS. This same patient had a femoral deep venous thrombosis identified by postoperative duplex ultrasonography. A second patient had IVC thrombus identified by IVUS, and placement was performed with contrast venography in the fluoroscopy suite. IVC measurements ranged from 18-28 mm in diameter.nnnCONCLUSIONSnIVUS accurately measures the IVC diameter and localizes the renal veins, allowing for exact placement of IVCFs. IVUS further avoids the need for contrast agents and for transport of critically ill patients. Bedside insertion of an IVcF with IVUS guidance is simple, safe, and accurate. Further assessment of this technique is warranted.

Retrohepatic vena cava and hepatic vein injuries: A simplified experimental methods of treatment by balloon shunt

BACKGROUNDnFecal contamination from colon injury has been thought to be the most significant factor for the development of surgical site infection (SSI) after trauma. However, there are increasing data to suggest that other factors may play a role in the development of postinjury infection in patients after colon injury. The purpose of this study was to determine the impact of gastric wounding on the development of SSI and nonsurgical site infection (NSSI) in patients with colon injury.nnnMETHODSnPost hoc analysis was performed on data prospectively collected for 317 patients presenting with penetrating hollow viscus injury. One hundred sixty-two patients with colon injury were subdivided into one of three groups: patients with isolated colon wounds (C), patients with colon and stomach wounds with or without other organ injury (C+S), and patients with colon and other organ injury but no stomach injury (C-S) and assessed for the development of SSI and NSSI. Infection rates were also determined for patients who sustained isolated gastric injury (S) and gastric injury in combination with organ injuries other than colon (S-C). Penetrating Abdominal Trauma Index, operative times, and transfusion were assessed. Discrete variables were analyzed by Cochran-Mantel-Haenszel chi2 test and Fishers exact test. Risk factor analysis was performed by multivariate logistic regression.nnnRESULTSnC+S patients had a higher rate of SSI infection (31%) than C patients (3.6%) (p = 0.008) and C-S patients (13%) (p = 0.021). Similarly, the incidence of NSSI was also significantly greater in the C+S group (37%) compared with the C patients (7.5%) (p = 0.07) and the C-S patients (17%) (p = 0.019). There was no difference in the rate of SSI or NSSI between the C and C-S groups (p = 0.3 and p = 0.24, respectively). The rate of SSI was significantly greater in the C+S patients when compared with the S-C patients (31% vs. 10%, p = 0.008), but there was no statistical difference in the rate of NSSI in the C+S group and the S-C group (37% vs. 24%, p = 0.15).nnnCONCLUSIONnThe addition of a gastric injury to a colon injury has a synergistic effect on the rate of postoperative infection.

Complications and Troubleshooting

Endovascular intervention is fundamentally and unequivocally different from “cut-and-sew” conventional surgery. Conceptually, this difference can be best characterized by recognizing the two hallmarks of percutaneous intraluminal therapy: remote catheter-mediated actions and indirect visualization. From a practical standpoint, this requires an enabling environment (workshop) and special instruments and tools designed for percutaneous transluminal application, as well as a different mindset on the part of the operator. It is, in a word, nonsurgical in nature. From conceptualization to bioskills, instrumentation and technical strategies, catheter-based interventional therapy has a distinct personality and an entirely unique set of needs in the three fundamental areas of workshop, instrumentation, and operator skills.1

Endovascular Intervention for Iliac Artery Disease: Indications and Techniques

Percutaneous endovascular intervention has gradually become the standard of care in the treatment of focal occlusive disease affecting the iliac arteries. Stent placement, as an adjunct to balloon angioplasty, represents a significant advancement because it can improve on the results of angioplasty and expand its applicability to more challenging lesions. Extensive aortoiliac occlusive disease, however, may still require conventional surgical reconstruction, although endovascular grafting and other technologies promise to offer less invasive therapeutic alternatives for such cases as well.Techniques of balloon angioplasty and endoluminal stent deployment must be viewed and learned within the larger context of interventional therapy in which imaging and percutaneous catheter skills emerge as the most critical components.