Daniel S. Kassavin

Sensitivity and specificity of CT scan and angiogram for ongoing internal bleeding following torso trauma

Background Occult internal bleeding in the trauma patient which remains undiagnosed and unaddressed has the potential to result in morbidity or mortality. Advancements in CT and angiography have played an integral role in the management of this patient population. Objective The purpose of the study was to identify the sensitivity and specificity of CT scan and angiography in detecting ongoing internal bleeding. Methods Consecutive patients who sustained torso trauma and subsequently underwent CT scan and angiography were included in this study. Data reviewed included clinical information, CT scan and angiography readings. Extravasations of contrast from CT scan and/or angiogram were considered positive for ongoing internal bleeding. Results From January 2002 through July 2007, 113 adult trauma patients sustaining torso trauma underwent CT scan of chest or abdomen followed by angiography. Sixty-six patients were negative for extravasation from either of the tests. Twenty-four of 35 patients had both positive CT scans and angiograms. Eleven patients with positive CT scans did not have bleeding on angiogram. Similarly, 12 out of 36 patients with positive angiograms did not show any extravasation of contrast on CT scan. Both modalities had a specificity of 100% based on clinical definition. The sensitivities of CT scan and angiogram were 74.5% and 76.6%, respectively. They were not significantly different (p=0.95). The negative predictive values for CT and angiogram were 84.6% and 85.7%. They were not significantly different (p=0.95) either. When CT scan was used alone, 25.5% of bleeding patients were missed. Conclusions The sensitivity of CT scan and angiography at detecting ongoing bleeding was around 75% across the torso injury spectrum.

The Transition to IVUS-Guided IVC Filter Deployment in the Nontrauma Patient

While prior reports have demonstrated intravascular ultrasound (IVUS)-guided inferior vena cava filter (IVCF) deployment to be feasible, larger reviews using the latest generation of filters in the nontrauma setting are absent. We review our experience with the deployment of 104 IVCFs using IVUS, whereby we transition from a combined use of IVUS with traditional road mapping techniques (venography and/or renal vein cannulation) to the sole use of the IVUS as the road mapping tool for IVCF insertion. The use of IVUS for IVCF deployment minimizes radiation exposure to patients and staff, minimizes patient contrast exposure, and minimizes dependency on auxiliary staff for fluoroscopy. Intravascular ultrasound IVCF deployments can be performed without increasing morbidity and mortality, case duration, or overall costs when compared to standard deployments. The learning curve for transitioning into the use of the IVUS as the primary road mapping tool for IVCF deployments is approximately 20 cases.

Cardiopulmonary Resuscitation and Associated Anatomic and Hemodynamic Changes in the Vena Cava: Risk Factors for Inferior Vena Cava Filter Migration?

Inferior vena cava filter (IVCF) migration and embolization is an infrequent but well-reported event in the literature, with rates of migration ranging 1–18% [1]. We present the case of a patient with recent IVCF placement who underwent unsuccessful aggressive fluid and cardiac resuscitation after cardiac arrest. Postmortem examination incidentally found that the patient had filter migration into the left renal vein. This case is presented as an opportunity to review the literature for IVCF migration associated with cardiopulmonary resuscitation (CPR). We conclude that the anatomic and pathophysiologic changes that occur within the inferior vena cava (IVC) during aggressive resuscitation are potential risk factors for IVCF migration. Thus, patients with a history of IVCF placement who subsequently undergo CPR should receive an abdominal radiographic film to exclude filter migration. We also propose that caval pathophysiology, in particular pathologic caval hemodynamics, in otherwise stable patients warrants greater attention when these patients undergo placement of retrievable IVCFs. Case Report

Initial systolic blood pressure and ongoing internal bleeding following torso trauma.

Objective: Recent studies have suggested that an initial systolic blood pressure (SBP) in the range of 90–110 mmHg in a trauma patient may be indicative of hypoperfusion and is associated with poor patient outcome. However, the use of initial SBP as a surrogate for predicting internal bleeding is yet to be validated. The purpose of this study was to assess the presenting SBPs in patients with torso trauma and evidence of ongoing internal hemorrhage. Setting and Design: This was a retrospective chart review conducted at the Level II Trauma Center. Patients and Methods: Adult patients who sustained trauma and underwent chest and/or abdominal computed tomography (CT) scans and angiography were included in the study. Demographic and clinical information was extracted from patients who had CT scan and angiography. Extravasation of contrast material on CT scan and angiography was considered positive for ongoing internal bleeding. Results: From January 2002 through July 2007, a total of 113 consecutive patients were included in this study. Forty-seven patients had evidence of ongoing internal bleeding (41.6%; 95% confidence interval: 32.4%, 51.2%). When comparing patients with and without ongoing bleeding, these two groups were similar in their gender, race, pulse, injury severity score and shock index. However, bleeding patients were typically older [mean (standard deviation): 44.5 (20.5) vs 37.3 (19.1) years; P = 0.051], had a lower initial SBP [116.2 (36.0) vs 130.0 (30.4) mmHg; P = 0.006] and had a higher Glasgow coma scale (GCS) [13.1 (4.0) vs 12.1 (4.4); P = 0.09]. From a multivariate logistic regression analysis, older age (P = 0.046) and lower SBP (P = 0.01) were significantly associated with bleeding, when controlled for gender, race and GCS. Among the 47 patients with ongoing bleeding, only seven patients (15%) had a SBP lower than 90 mmHg and 25 patients (53%) had a SBP higher than or equal to 120 mmHg. The spleen was the most frequently injured organ identified with active bleeding. Conclusions: Initial SBP cannot predict the ongoing internal bleeding.

The combined use of proton pump inhibitors and antibiotics as risk factors for Clostridium difficile infection

Abstract Purpose A review of the incidence of Clostridium. difficile infection (CDI) at our hospital was performed due to the morbidity of CDI in its fulminate form, reports of the increased incidence of CDI in the United States and the increased use of medications associated with its onset. Methods The study was retrospective and took place over a 9-month period, from 1 January 2009 through 30 September 2009. Results There were 88 cases of CDI in the course of the review which amounted to 5.1 infections per 1000 patient hospital admissions. The percentage of overall admissions that were prescribed antibiotics and proton pump inhibitors (PPI), PPI alone or antibiotics alone were 17.1%, 15.5% and 24.3%, respectively. Of all cases of CDI, 59.1% of patients were on both a PPI and antibiotic, 9.1% were on a PPI alone and 13.6% were on an antibiotic alone. Patients on both proton pump inhibitors and antibiotics had an odds ratio of 8.30 ( P

Cone over Guide Wire Technique for Difficult IVC Filter Retrieval

Retrievable inferior vena cava (IVC) filters are placed in patients who are at temporary increased risk for pulmonary embolism, with or without contraindication for anticoagulation, with the expectation of subsequent removal. The failure to retrieve nonpermanent IVC filters is an increasingly encountered dilemma for vascular interventionalists. One of the more common causes of technical failure of retrieval is the presence of tilt in the orientation of the IVC filter, which may result in the retrieval hook abutting the wall of the IVC, preventing contact with the removal system [1]. This issue may be compounded by endothelialization of the filter hook [2]. We describe a nonconventional method for the retrieval of tilted IVC filters in two patients. This method uses a femoral access site that is contralateral to the direction of filter tilt in addition to the right internal jugular vein (IJV) access site. A cone-over-guide wire is then used to retrieve the filter, which has been realigned to the caval axis by the gentle application of tension on the guide wire ends. This technique can be used for filters of both the half-basket and double-basket design, when conventional and other nonconventional techniques fail and may make retrieval difficulties pertaining to filter hook endotheliazliation less relevant.

Delayed Release of an Amplatzer Vascular Plug in the Treatment of a Hypogastric Artery Aneurysm

The occlusion of the internal iliac artery (IIA) is indicated for the prevention of type II endoleak in patients undergoing endovascular repair of abdominal aortic and/or iliac aneurysms in which the stent graft may occlude the ostia of the IIA. Although the overall consensus among vascular specialists is that the occlusion of the IIA is safe due to extensive vascular collateralization, the risk of ischemic complications has been well documented and may include proximal extremity claudication, compartment syndrome, gluteal necrosis, colonic ischemia, or neurologic deficits. The incidence of these complications may be increased in patients having undergone prior vascular interventions or those who have bilateral IIA occlusion. We present the case of a patient with a right IIA aneurysm following multiple vascular interventions. On planning treatment options, the patient was believed to be at high risk for developing complications following proposed occlusion of his right IIA aneurysm. Therefore, a retrievable modality was selected. An amplatzer vascular plug (AVP; AGA Medical Corporation, Plymouth, Minnesota) was used in a 3-step process, composed of deployment, observation for potential sequela, and delayed release once the patient demonstrated that the permanent occlusion of the IIA was tolerated. The patient was a 64-year-old male with an extensive history of pelvic vascular disease and intervention who was diagnosed with a 4.5 x 4.1 cm right IIA aneurysm on screening computed tomography (CT) scan. The patient was asymptomatic. Four years prior the patient had undergone an open repair of a 6.9 cm infrarenal abdominal aortic aneurysm (AAA) with right iliac involvement. One year later, the patient developed a left IIA aneurysm which was treated with coil embolization of the IIA and deployment of an overlying stent graft. During the current admission, the patient was brought to the operating room and the right common femoral artery was catheterized and arteriogram performed at the right IIA which confirmed the preoperative CT measurements of the IIA aneurysm. The neck of the aneurysm was measured to be 8 mm. A 10-mm plug was selected for arterial occlusion. The left brachial artery was selected as the access site for AVP delivery and deployment because of the patient’s history of prior AAA repair and resulting high bifurcation which would have made it difficult to come up-and-over the iliac in a retrograde fashion had a contralateral femoral approach been selected. A cut down was performed to minimize inadvertent injury to the axillary brachial nerve plexus. A 5F guiding catheter was advanced to the ostia of the right IIA from the left brachial access site. The 10-mm AVP was deployed into the neck of the right IIA aneurysm. With the AVP attached to its delivery wire, the catheters were fixed in place and the patient was observed in the post anesthesia care unit (PACU) for 6 hours. The patient remained symptom free and was brought back to the operating room and underwent completion arteriography, which demonstrated occlusion of the IIA aneurysm by the AVP. The AVP was then successfully released from the delivery wire. The patient was heparinized throughout the procedure to prevent access site thrombosis. The patient remained free of symptoms, with follow-up CT demonstrating thrombosis of the right IIA. This report describes the delayed release of an AVP to qualitatively confirm adequate collateral flow in the pelvic vasculature prior to its therapeutic deployment. The ability to perform this procedure was dependent on the AVP being able to effectively occlude and thrombose the vessel in a timely fashion and the ability to re-sheath and remove the AVP if ischemic symptoms were to develop. Both these requirements have been documented in the literature. The AVP may possibly be used in a similar fashion in other segments of the circulatory system to determine the physiologic effects and safety of vessel occlusion prior to definitive release.