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Biomedical subjects

W Castaneda-Zuniga

Publications and source records attributed to W Castaneda-Zuniga.

At least 19 recordsLinked to original sources
PubMed1998

Initial clinical experience with colonic stent placement.

BACKGROUND: The purpose of this study is to review initial experience with a colonic stent as an alternative to colostomy in patients with colonic obstruction. METHODS: Ten patients diagnosed with acute colonic obstructions from both benign and malignant causes underwent stent placement. Self-expandable metallic stents were deployed using fluoroscopic guidance. Patients were followed up clinically until removal of the stent or death. RESULTS: Nine of the 10 patients who underwent colonic stent placement achieved clinical decompression within 6 hours. Six patients underwent standard mechanical bowel preparation and elective resection of obstructing lesions. The other 4 patients received stent placement for palliative purposes. Complications included 4 cases of migration and 1 death. Migrated stents in the rectum were easily retrieved and replaced using fluoroscopic techniques. There were no perforations. CONCLUSION: Placement of self-expandable metallic stents for acute colonic obstructions may allow patients to undergo elective surgical resection avoiding possible colostomy.

Acute Disease↗
PubMed1992

Pneumothorax after lung biopsy: prevention with transpleural placement of compressed collagen foam plugs.

The effectiveness of pleural sealing with a compressed collagen foam plug in preventing the development of pneumothorax was evaluated in a prospective, comparative study of 50 patients undergoing transthoracic needle biopsies. The 4-cm-long plug was deposited through the thin-walled guidance needle at the end of the procedure in a position where it would cross both the visceral and the parietal pleura. The prevalence of postbiopsy pneumothorax was 28% (seven of 25 patients) in the control group and 8% (two of 25 patients) in the plug group. In each study group, two patients with pneumothoraces required chest tubes. Although further experience is necessary, the authors conclude that transpleural collagen foam plug placement may be an effective supplement for transthoracic needle biopsies.

Biopsy, Needle↗
PubMed1991

LGM vena cava filter: objective evaluation of early results.

One hundred one LG-Medical (LGM) vena cava filters were placed in 97 patients at four institutions. Placement was a complete technical success in 90% (91 of 101). In 6% of attempts, LGM filter insertion was complicated by incomplete opening of the filter. Pulmonary embolism after filter placement was not definitely demonstrated in any patient. The probability of inferior vena cava patency was 92% at 6 months after filter insertion. Thrombosis at the insertion site was seen in eight of 35 patients (23%) evaluated with duplex ultrasound or venography. Thrombus was observed in 37% of filters at follow-up examination, with cephalic extension of thrombus above the filter in 20% of all patients examined. Filter migration (greater than 1 cm) was seen in 12%; significant angulation was observed in only one patient (2%). In vitro experimentation demonstrated that incomplete opening of the LGM filter during placement can be avoided, in part, by brisk retraction of the insertion cannula. The low-profile introducer system of the LGM filter allows increased alternatives in selecting the site for filter insertion. The low-profile system also makes outpatient filter placement a possibility. No significant difference in the prevalence of thrombosis at the insertion site following LGM filter insertion was noted compared with previous results reported for percutaneous transfemoral placement of the Greenfield filter. The nonopaque sheath does not permit careful localization prior to filter deposition. Modification of the LGM filter to include a radiopaque sheath is suggested.

Equipment Design↗
PubMed1989

Transplant renal artery stenosis.

A group of 31 patients with transplant renal artery stenoses was identified among 2002 patients undergoing renal transplantation at the University of Minnesota; 29 of the stenoses were at the anastomosis. A total of 43 procedures were performed to correct the stenosis. Angioplasty was performed 25 times, with 3 patients cured and 2 patients improved; 20 procedures resulted in a poor result (3) or a failure (17). The failures were usually due to recurrent stenosis (7 patients) or to arterial injury that resulted in graft loss (4 patients) or successful emergency surgery to save the transplant (3 cases). Surgical repair of the stenosis was performed 18 times. No grafts were lost and 13 patients were cured or improved. These data suggest that angioplasty for anastomotic stenosis yields poor results and that a surgical repair is probably warranted. All 7 patients who had a poor results or failed a technically successful intervention did not have a rise in creatinine secondary to captopril or had a systolic pressure gradient of less than 60 mmHg across the anastomosis. These data also suggest that patients without physiological evidence of renal artery stenosis may not have improvement in their hypertension following repair.

Angioplasty, Balloon↗
PubMed1988

Classification of and techniques for the reconstitution of acquired strictures in the region of the ureteropelvic junction.

We performed percutaneous intrarenal surgery on 22 patients with acquired strictures of various degrees of severity in the region of the ureteropelvic junction. Of 17 patients with strictures through which a guide wire could be passed (type 1) 8 (47 per cent) had good or excellent long-term results. Of 4 patients with strictures that were patent radiologically but through which a guide wire could not be passed (type 2) only 1 (25 per cent) had good long-term results. The patient with a stricture that totally obliterated the lumen (type 3) suffered recurrence. We conclude that percutaneous techniques for the management of acquired strictures in the region of the ureteropelvic junction can be difficult technically and currently are most successful in the treatment of strictures of short duration that occur after pyeloplasty.

Adult↗
PubMed1988

Percutaneous intrarenal marsupialization of a perirenal cystic collection--endocystolysis.

We report a case of a recurrent perirenal cyst after 4 previous attempts to obliterate the cyst by more conventional means percutaneously and by open surgery. Endocystolysis, a technique for the internal marsupialization of a cyst into the renal collecting system, was used successfully to obliterate the cyst. This case and the technique of endocystolysis are described in detail.

Adult↗
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↗
PubMed1986

Percutaneous techniques for the management of caliceal diverticula containing calculi.

Most frequently caliceal diverticula are found incidentally on routine excretory urograms. Smaller diverticula are associated with a low incidence of complications but larger diverticula with a narrow communication to the main collecting system will predispose to calculous formation as a result of stasis of urine within the diverticulum. The techniques used and results achieved in 10 patients with such calculi who have been successfully managed percutaneously are discussed. Particular reference is made to techniques used specifically to obliterate the diverticula.

Adult↗
PubMed1986

Coil-in-coil technique for vascular embolization.

A new technique for vascular embolization using two Gianturco steel coils is described. The authors used a "coil-in-coil" technique to embolize the arteries of 12 dogs. In this technique a large coil is introduced into the artery followed by a smaller coil, which is delivered with a special introducer into the lumen of the first coil. Two coils can therefore be introduced into a shorter length of vessel. This method was as effective as "packing" the vessel with two coils in a row. The coil-in-coil technique is especially advantageous for use in infants and children with short, anomalous vessels, minimizing the risk of coil dislodgment into normal peripheral vessels.

Animals↗