Hypogastric artery embolization in endovascular abdominal aortic aneurysm repair.

PURPOSE: Iliac artery anatomy is a central factor in endoluminal abdominal aortic aneurysm therapy. It serves as the conduit for graft deployment and as the region of distal graft seal. Thirty-eight percent of iliac vessels in our patients require special treatment because of aneurysms, tortuosity, or small size. Bilateral hypogastric artery exclusion has been avoided because of concerns of colorectal ischemia, hip/buttock claudication, and impotence. We suggest that elective, staged, bilateral hypogastric embolization can be performed safely with reasonably low morbidity and can expand the anatomic boundaries for stent-graft abdominal aortic aneurysm repair. METHODS: This study was performed as a retrospective chart review of patients requiring hypogastric artery embolization for endovascular repair of abdominal aortic aneurysms between June 1998 and June 2000. Patients with otherwise appropriate anatomy and common iliac artery aneurysms were informed of the option for stent-graft repair with internal iliac artery embolization with its risks of impotence, hip/buttock claudication, and bowel ischemia. Patients underwent unilateral or staged bilateral coil embolizations of their proximal hypogastric arteries with an approximate 1-week interval between procedures. Hospital and office records were reviewed; phone interviews were performed. Follow-up ranged from 1 to 12 months. RESULTS: During a 24-month period, 65 patients underwent endovascular abdominal aortic aneurysm repair; 18 patients (28%) required hypogastric artery embolization. Seven (39%) of these patients underwent bilateral embolization. There were no episodes of clinically evident bowel ischemia. Lactate levels were normal in all measured patients. Postoperative fevers (> 101.0 degrees F) were documented in 10 (56%) of 18 patients. The average white blood cell count was 12.8 x 10(9)/L (range, 8.5-22.9). There were no positive blood culture results. The return to the full preoperative diet occurred in 1 to 3 days. Hip/buttock claudication occurred in approximately 50% of patients with persistent but improved symptoms at 6 months. Eighty-seven percent of patients had preoperative erectile dysfunction. Only two patients noted worsening of erectile function postoperatively. CONCLUSIONS: Preliminary results indicate that bilateral hypogastric artery embolization can be performed, when necessary, with reasonable morbidity in patients undergoing stent-graft abdominal aortic aneurysm repair.

Acoustic field variability induced by time evolving internal wave fields

A space- and time-dependent internal wave model was developed for a shallow water area on the New Jersey continental shelf and combined with a propagation algorithm to perform numerical simulations of acoustic field variability. This data-constrained environmental model links the oceanographic field, dominated by internal waves, to the random sound speed distribution that drives acoustic field fluctuations in this region. Working with a suite of environmental measurements along a 42-km track, a parameter set was developed that characterized the influence of the internal wave field on sound speed perturbations in the water column. The acoustic propagation environment was reconstructed from this set in conjunction with bottom parameters extracted by use of acoustic inversion techniques. The resulting space- and time-varying sound speed field was synthesized from an internal wave field composed of both a spatially diffuse (linear) contribution and a spatially localized (nonlinear) component, the latter consisting of solitary waves propagating with the internal tide. Acoustic simulation results at 224 and 400 Hz were obtained from a solution to an elastic parabolic equation and are presented as examples of propagation through this evolving environment. Modal decomposition of the acoustic field received at a vertical line array was used to clarify the effects of both internal wave contributions to the complex structure of the received signals.

Acoustic normal mode fluctuation statistics in the 1995 SWARM internal wave scattering experiment

In order to understand the fluctuations imposed upon low frequency (50 to 500 Hz) acoustic signals due to coastal internal waves, a large multilaboratory, multidisciplinary experiment was performed in the Mid-Atlantic Bight in the summer of 1995. This experiment featured the most complete set of environmental measurements (especially physical oceanography and geology) made to date in support of a coastal acoustics study. This support enabled the correlation of acoustic fluctuations to clearly observed ocean processes, especially those associated with the internal wave field. More specifically, a 16 element WHOI vertical line array (WVLA) was moored in 70 m of water off the New Jersey coast. Tomography sources of 224 Hz and 400 Hz were moored 32 km directly shoreward of this array, such that an acoustic path was constructed that was anti-parallel to the primary, onshore propagation direction for shelf generated internal wave solitons. These nonlinear internal waves, produced in packets as the tide shifts from ebb to flood, produce strong semidiurnal effects on the acoustic signals at our measurement location. Specifically, the internal waves in the acoustic waveguide cause significant coupling of energy between the propagating acoustic modes, resulting in broadband fluctuations in modal intensity, travel-time, and temporal coherence. The strong correlations between the environmental parameters and the internal wave field include an interesting sensitivity of the spread of an acoustic pulse to solitons near the receiver.

Modeling mode arrivals in the 1995 SWARM experiment acoustic transmissions

As part of the Shallow Water Acoustics in a Random Medium (SWARM) experiment, a 16 element WHOI vertical line array (WVLA) was moored in 70 m of water off the New Jersey coast. A 400-Hz acoustic tomography source was moored some 32-km shoreward of this array, such that an acoustic path was created that was anti-parallel to the primary propagation direction for shelf-generated internal wave solitons. The presence of these soliton internal waves in the acoustic waveguide causes significant coupling of energy between propagating acoustic modes, creating fluctuations in modal intensities and modal peak arrival times, as well as time spreading of the pulses. Two methods by which acoustic propagation and scattering in soliton-filled waveguides can be modeled are presented here in order to understand and explain the scattering observed in the SWARM field data. The first method utilizes the Preisig and Duda [IEEE J. Ocean. Eng. 22, 256-269 (1997)] Sudden Interface Approximation (SIA) to represent the solitons. The second method, which is computationally slower, uses a finely meshed, "propagated" thermistor record to simulate the solitons in the SWARM experiment waveguide. Both numerical methods are found to generate scattering characteristics that are similar to the SWARM field data.

[Malaria: 4 case reports with "atypical" symptoms (author's transl)]. / Malaria: 4 Falldarstellungen mit "atypischem" Verlauf.

Four cases of malaria are described. Five to nine days elapsed between the onset of clinical symptoms and the beginning of the anti-malaria chemotherapy. One of the patients died under signs of massive and nearly synchronous hemolysis during the last two hours of treatment. The Malaria tropica disease of the first and the second patient were first diagnosed as common cold with enteritic symptoms; the third patient showed signs of abdominal thyphoid fever and developed symptoms of intravascular coagulation. With the fourth case-Malaria tertiana-it shall be remembered that, if chemoprophylaxis starts too late, the disease is not suppressed but can be delayed: incubation period lasted ten weeks. The diagnostic procedure for the clinician and the pathogenetic mechanism are discussed: massive hemolysis and the possible influence of the chloroquine therapy, the intravascular coagulation and the elevation of the IgE level.

The surgical uncovering and orthodontic positioning of unerupted maxillary canines.

1. The presence of the maxillary canine is vital to the function and esthetics of the dental complex. The availability of this tooth must be carefully considered during an orthodontic diagnosis. Lack of space is the most common cause of canine impaction. Other contributing factors are that this tooth has the longest period of developmenent and that it is bigger longer, and travels farther while erupting than any other tooth. 2. Proper management of unerupted canines is a challenge to the dental practitioner. Maxillary canines are found impacted to both the buccal and the lingual. Palatal impactions are much more common than labial impactions, but, of the two, labial impactions are more difficult to manage. 3. An appropriate surgical procedure which opens to the crowns of unerupted teeth is a key to uneventful orthodontic positioning of these teeth. Packing the follicular space with baseplate gutta-percha and keeping the crown open to the oral cavity with surgical WondrPak is an effective method of making the tooth erupt into the oral cavity. 4. Modern preformed bands and improved cements make the placement of attachment on malposed teeth relatively easy. Direct bonding techniques are also of value in the management of unerupted teeth. 5. It is practical to move teeth orthodontically from seemingly impossible positions into ideal alignment. Such teeth will function normally, and no evidence will be left of their original position or of their having been moved over long distances.