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Biomedical subjects

D W Hunter

Publications and source records attributed to D W Hunter.

At least 109 records · Page 6Linked to original sources
PubMed1988

Urinary obstruction in renal transplants: diagnosis by antegrade pyelography and results of percutaneous treatment.

We reviewed our experience with 51 renal transplants to evaluate the accuracy of antegrade pyelography as compared with that of sonography and nuclear renography in the diagnosis of transplant obstruction. Also, the results of percutaneous treatment were analyzed in 44 of these patients. Obstruction was clinically suspected in all of the patients (increased serum creatinine levels and decreased urine output). Antegrade pyelography showed obstruction in 44 (86%) of the 51 patients, and nephrostomy drainage catheters were inserted. Sonography showed pyelocaliectasis in all 49 cases in which it was performed; in 42, the pyelocaliectasis was due to obstruction (14% false-positive rate). Nuclear renography showed obstruction in only six (18%) of 33 cases in which it was performed; all six cases proved to be obstructed (0% false-positive rate and 82% false-negative rate). Twenty-two (50%) of the 44 patients treated with nephrostomy drainage were managed successfully without surgical intervention; seven of these 22 required balloon dilation of ureteric strictures in addition to catheter decompression of the collecting system. The average duration of catheterization required for successful percutaneous treatment was 35 days. This experience suggests that antegrade pyelography has a definite role in the workup of patients suspected of having renal transplant obstruction. The percutaneous access permits successful catheter drainage. Compared with antegrade pyelography, sonography is reasonably accurate in determining the presence of urinary obstruction, although false-positive diagnoses are found in a substantial number of patients. Nuclear renography is not, however, a useful indicator of obstruction owing to its high false-negative rate. Percutaneous treatment of urinary obstruction in transplantation patients proves successful in approximately 50% of cases.

Humans↗
PubMed1988

Urine leaks after renal transplantation: value of percutaneous pyelography and drainage for diagnosis and treatment.

We reviewed our experience with 12 renal transplant patients who had urine leaks to compare the accuracies of sonography and nuclear renography with that of antegrade pyelography in establishing the diagnosis. The leak was proved by surgery in 11 of the 12 cases. We also determined the role of diverting percutaneous nephrostomy drainage in the treatment of such leaks. The diagnosis was established by sonography in eight (67%) of the 12 patients. Nuclear renography, performed in nine patients, showed decreased renal function but showed the leak in only three (33%) of the nine cases. Antegrade pyelography, performed in all 12 patients, showed leakage in 10 (83%). In the other two patients, follow-up nephrostograms done within 24 hr showed leaks near the ureterovesical anastomotic site. Seven of 11 patients who were managed with a combination of percutaneous nephrostomy drainage and surgical reconstruction were treated successfully (i.e., a functioning graft was retained); however, only one patient was managed successfully by percutaneous methods alone. Antegrade pyelography is more accurate than sonography and nuclear renography in the detection of urine leakage after renal transplantation. However, percutaneous nephrostomy drainage appears useful only as an adjunct to surgery for treatment of this complication.

Adolescent↗
PubMed1987

Use of streptokinase for the salvage of a free flap: case report and review of the use of thrombolytic therapy.

This is the first case report of the clinical use of intraoperative streptokinase to promote free flap salvage. A latissimus dorsi free flap was mobilized to cover a scalping type injury. After 4 1/2 hours of ischemia and recurrent thrombosis, streptokinase was perfused into the thoracodorsal artery (7,500 units of streptokinase in 30 cc of normal saline). The free flap was exposed to this concentration of streptokinase for 10 minutes followed by drainage of the venous effluent in order to avoid possible deleterious systemic effects of the streptokinase. Good flow throughout the free flap resulted, and the flap remained viable, providing good coverage for the patient's skull. Controversies regarding the no-reflow phenomena and the use of various thrombolytic agents are discussed.

Aged↗
PubMed1987

Limited usefulness of carbon dioxide as a contrast agent for cholangiography.

Carbon dioxide (CO2) was unsuccessfully used as a biliary contrast agent in 9 of 10 patients undergoing percutaneous transhepatic cholangiography prior to biliary drainage. The technique involved hand injection of 10-20 cc CO2 through the Chiba needle in an attempt to fill preferentially the anterior biliary radicals. Although CO2 remains a useful agent in many instances, particularly for percutaneous nephrostomy, its usefulness in the biliary tract is severely limited.

Carbon Dioxide↗
PubMed1987

Percutaneous transhepatic biliary endoscopic procedures.

Two cases are presented to demonstrate the acceptability of the percutaneous route for performing endoscopic procedures in the biliary tree. They involved debridement of an atypical villoglandular polyp and ultrasonic lithotripsy of intrahepatic stones. Both cases serve to introduce percutaneous biliary endoscopy as a viable alternative for diagnosis and therapy in selected cases.

Adult↗
PubMed1987

Retrieving the Amplatz retrievable vena cava filter.

The new Amplatz retrievable filter was placed 15 times into the inferior vena cava (IVC) of 7 dogs. Retrieval of the filter was attempted in 11 cases after 1 week and in 3 cases after 2 weeks. The retrieval was successful and without complication in all 14 cases. The 15th placement resulted in thrombotic occlusion of the IVC, and no retrieval was attempted.

Animals↗
PubMed1987

Misplacement of a vena cava filter in the retroperitoneum.

An inferior vena cava filter was misplaced into the pericaval retroperitoneum. This was probably secondary to placement into and avulsion of the right spermatic vein. The filter delivery system was modified, and such misplacement should now be impossible.

Filtration↗
PubMed1987

Balloon occlusion femoral angiography prior to in-situ saphenous vein bypass.

The advent of the in situ saphenous vein bypass procedure for peripheral lower extremity ischemic disease has placed new demands on the angiographer. It is imperative that the small runoff arteries of the calf be seen beyond the level of the ankle to include evaluation of the patency of the plantar arch. Balloon occlusion femoral angiography (BOFA) has been used in 45 consecutive lower extremities in 40 patients referred for proposed in situ saphenous vein bypass; excellent visualization of the plantar arch on the first run was obtained in 40 of 45 extremities (88.9%). The patients included 35 (87.5%) insulin-dependent diabetics with severe proximal arterial disease. Initially, in situ candidates were studied using conventional "runoff" methods; it was rarely possible to visualize the upper trifurcation vessels let alone the plantar arch by this conventional method. The BOFA method was used to provide excellent visualization of the plantar arch and foot arteries. It permits use of smaller contrast medium volumes, provides all the arteriographic anatomy on one 51 inch long film, and is safe.

Adult↗
PubMed1987

Percutaneous endoscopic fulguration of a large volume caliceal diverticulum.

Currently, the optimal approach to a caliceal diverticulum appears to be direct puncture into the diverticulum with subsequent dilation and stenting of the narrow ostium with a large nephrostomy tube. However, further maneuvers might be necessary in cases of large volume caliceal diverticula. We describe a patient with a large caliceal diverticulum (7.5 cm.) in whom percutaneous endoscopic fulguration was used successfully as an additional technique to assure obliteration of the diverticulum.

Adult↗
PubMed1987

Alternative treatment of prostatic urethral obstruction secondary to benign prostatic hypertrophy. Non-surgical balloon catheter prostatic dilatation.

Benign prostatic hypertrophy (BPH) produces symptoms that currently can only be treated surgically either by open or endoscopic prostatectomy. We have undertaken animal (1) and human studies to determine if invasive radiologic techniques utilizing balloon catheters could be applied to the treatment of this common ailment. We report a series of twelve patients treated by retrograde transurethral balloon catheter prostatic dilatation. The procedure is performed using topical anesthesia with a specially designed balloon catheter (Medi-Tech, Inc.). The procedure is done on an outpatient basis and is completed within approximately 15 minutes. Relatively long-term results have resulted in persistent relief of symptoms. No complications have been encountered. We anticipate that balloon dilatation of the prostatic urethra will have a major impact on the treatment of BPH based on the promising preliminary results. Transurethral resection of the prostate (TURP) is associated with moderate morbidity and significant cost which can be reduced by the proposed procedure.

Catheterization↗
PubMed1987

Safe splenoportography.

The records of 37 patients who had undergone splenoportography, including one group of 12 who were studied before 1976 and a second group of 25 who were studied after 1977, were reviewed. The primary difference was that in the second group, the tract in the spleen was occluded with absorbable gelatin sponge (Gelfoam) plugs as the needle was withdrawn. In addition, there were minor changes in technique, such as changes in the needle puncture angle and entry site. When the new technique was used, there was a significant decrease in the complications traditionally associated with splenoportography. This procedure is safe and deserves to be considered the procedure of choice in patients in whom precise anatomic information is needed preoperatively that cannot be obtained with noninvasive procedures such as ultrasound or magnetic resonance imaging.

Adolescent↗
PubMed1987

New heavy-duty exchange guide wire.

A major drawback of currently used exchange guide wires is insufficient stiffness, causing them to buckle or dislodge when used during catheter exchanges. A new heavy-duty exchange guide wire is described that facilitates catheter exchanges around sharp corners, such as those encountered during various cardiac interventional procedures. The wire was successfully used in experimental valvuloplasty and experimental dilation of the ductus arteriosus.

Angiography↗
PubMed1987

Improved vessel dilator for percutaneous catheterization.

Three commercial vessel dilators and a dilator of an improved design were tested during percutaneous catheterization in 16 mongrel dogs to evaluate arterial damage produced with their use. The results indicate that, although all dilators often produce arterial damage, the improved design produced much less damage. In addition, lesions were less severe overall. The dilator has been safely and successfully used in patients for percutaneous vessel catheterization for the past 30 years at the authors' institution.

Angiography↗
PubMed1987

Prostatic urethra: experimental dilation in dogs.

An animal study was undertaken to develop a balloon dilation technique that could be used in humans to treat the common ailment of benign prostatic hypertrophy. Dogs were used as a model because of the similarities in the prostate between the two species and the ready availability of the canines. A retrograde transurethral approach was used for dilation. Balloon catheters, 8-20 mm in diameter, were used. Significant, long-lasting dilatation of the prostatic urethra was not accomplished until 20-mm balloons (or two 10-mm ones) inflated for 10 minutes were used. The animals were followed for up to 14 months. No deleterious histologic effects of dilation were identified within the urethra or prostate that could lead to stenosis of the prostatic urethra in later stages.

Animals↗
PubMed1987

Benign prostatic hypertrophy: retrograde transurethral dilation of the prostatic urethra in humans. Work in progress.

Retrograde transurethral balloon dilation of the prostatic urethra was performed in five human volunteers with benign prostatic hypertrophy. Each patient underwent cystoscopy, uroflow studies, voiding cystourethrography, retrograde urethrography, and magnetic resonance imaging before dilation and at defined intervals afterward. The longest follow-up to date is 8 months. Patients were given topical anesthetics and mild sedatives, and dilation was performed with a 25-mm urethroplasty balloon catheter inflated at 3-6 atm for 10 minutes. All catheter manipulations were done with a guide wire and under fluoroscopic control. Significant resolution of symptoms of prostatism was seen in four patients. The unsatisfactory results in the last patient were believed to be caused by ineffectual dilation of predominantly middle lobe hypertrophy--a condition that is now regarded as a contraindication to dilation. This technique has promise to replace transurethral resection of the prostate as the treatment of choice for this common male ailment.

Aged↗
PubMed1987

Percutaneously applied ureteral clips: treatment of vesicovaginal fistula.

Percutaneous techniques to manage urinary fistulas have had limited success. To overcome this, self-closing metallic clips were developed to occlude the ureter. The clips are applied through a percutaneously placed 30-F Teflon sheath. A case is reported in which the clips and new technique were successfully used.

Aged↗
PubMed1987

Modified sheath introducer for reduced arterial damage.

An introducer-sheath dilator is described, which was modified to protect the leading lip of the sheath during insertion, thus reducing arterial damage. The new sheath and a standard sheath were inserted into the femoral arteries of six dogs. Subsequent histologic examination of the arteries proved the new sheath to be both safe and effective.

Animals↗