Biomedical subjects

F F Illescas

Publications and source records attributed to F F Illescas.

At least 19 recordsLinked to original sources

PubMed1998

Gallbladder cancer: can ultrasonography evaluate extent of disease?

This study reviews the spectrum of sonographic findings in patients with gallbladder cancer, attempts to determine if sonography can identify patients with potentially resectable disease, and emphasizes the limitations of ultrasonography in the evaluation of -gallbladder cancer. Thirty-five consecutive patients with histologically proven gallbladder carcinoma who had preoperative abdominal ultrasonography and surgery were identified. Involvement of the gallbladder and gallbladder fossa, metastases, bile ducts, portal vein, and adjacent lymph nodes was assessed sonographically. The extent of disease and staging as revealed by sonography was compared to operative and surgical pathologic findings. Masses in the gallbladder or gallbladder fossa were present at surgery in 26 patients; 22 (85%) of these masses were shown by sonography. Sonography identified six (67%) of nine cases of pathologically confirmed liver metastases, 11 (79%) of 14 cases of bile duct involvement, and two (67%) of three cases of portal venous involvement by tumor. Sonography revealed lymph node metastases in only five (36%) of 14 patients. None of the 12 cases with peritoneal metastases was identified sonographically. By surgical staging 16 (46%) patients had potentially resectable disease (stage III or less), and 19 (54%) patients had unresectable stage IV disease. Sonography correctly identified 15 (94%) of 16 patients with potentially resectable disease and seven (37%) of 19 patients with advanced disease. Twelve patients with advanced disease were under-staged: nine had peritoneal metastases, two had liver metastases, and one had celiac adenopathy, which was not shown by sonography. In conclusion, sonography is reliable in the detection of a primary gallbladder mass or of local extension of tumor into the liver. However, sonographic findings do not accurately reflect the full extent of disease, and sonography is particularly limited in the diagnoses of metastases to the peritoneum and lymph nodes.

Adult↗

PubMed1996

Accuracy of sonography in the evaluation of calf deep vein thrombosis in both postoperative surveillance and symptomatic patients.

OBJECTIVE: The purpose of this study was to determine the accuracy and to assess the interobserver variability of compression sonography (CS) in detecting isolated calf deep vein thrombosis (DVT) in postoperative and symptomatic patients without clinical or contrast venographic indication of previous lower extremity DVT. SUBJECTS AND METHODS: A prospective double-blinded study was undertaken on 287 consecutive legs using contrast venography (CV) as the gold standard. One hundred seventy-nine legs were from the postoperative group, and 108 legs were from the symptomatic group. The CS technique was used to diagnose DVT, and color Doppler imaging was used only as a road map. Calves were examined while the patient was sitting. Also, interobserver agreement was measured in the CS evaluation of calf veins of another group of 54 symptomatic legs. RESULTS: Forty (22%) CVs and 13 (7%) CS examinations for calf assessment were indeterminate in the postoperative group as compared with 33 (30%) and 10 (9%) in the symptomatic group. The sensitivity, specificity, negative predictive value, and positive predictive value of CS in detecting calf DVT with or without extension to above-the-calf veins were 92% (confidence interval [Cl], 82-100%), 100%, 98% (Cl, 95-100%), and 100%, respectively, in the postoperative group and 86% (Cl, 72-100%), 96% (Cl, 90-100%), 94% (Cl, 87-100%), and 90% (Cl, 77-100%), respectively, in the symptomatic group. The sensitivity of CS was 92% (Cl, 81-100%) in the postoperative and 88% (CL, 65-100%) in the symptomatic group with isolated calf DVT. Of all calf muscular branch DVTs, 52% were detected by CS alone as compared with 21% seen on CV alone. The kappa value for the CS assessment of isolated calf vein DVTs was 0.60. CONCLUSION: Sonography is a highly accurate test with acceptable reproducibility for the detection of DVT in calf veins in both postoperative and symptomatic patients. Technically adequate calf assessment can be achieved in the majority of patients if the calf examination is performed with the patient sitting.

Adult↗

PubMed1993

Renal streak artifact during contrast-enhanced CT: comparison of low versus high osmolality contrast media.

Two hundred abdominal computed tomographic (CT) scans in 200 patients, 100 performed with low osmolality contrast (ioversol 68%, 100 ml) and 100 performed with high osmolality contrast (diatrizoate meglumine 60%, 150 ml), were retrospectively evaluated for the presence of renal streak artifact. Contrast was administered by hand injection at a rate of approximately 1-2 ml/s and sequential scanning was employed. Of the scans performed with high osmolality contrast, 70% had no artifact, 28% had minimal artifact, and only 2% had marked artifact. Only 26% of the exams performed with low osmolality contrast were artifact-free, whereas 53% demonstrated minimal artifact and 21% demonstrated marked artifact. The likelihood of encountering renal streak artifact when using low osmolality contrast agents is almost seven times greater than when high osmolality contrast agents are used.

Adult↗

PubMed1991

Accuracy of ultrasound in counting and measuring gallstones.

A prospective study of accuracy of ultrasound in measuring and counting gallstones was undertaken in 30 patients undergoing cholecystectomy. Stones were correctly counted (up to five) in 27 of 30 patients. Ninety-three of 106 stones (88%) examined were measured accurately (with a 2 mm error margin). The size of the smaller stones tended to be overestimated, whereas the size of the larger stones tended to be underestimated. When nonoperative treatment of gallstones is considered, ultrasound can be used as the first examination to identify patients who will not be eligible for one or another protocol on the basis of size or number of stones.

Cholelithiasis↗

PubMed1990

Intrahepatic portal venous system: variations demonstrated with duplex and color Doppler US.

Seventeen cases of variations of the intrahepatic portal venous system were investigated with use of duplex and color Doppler ultrasound (US). Seven cases involved absence of the horizontal segment of the left portal vein, with portal supply to the left lobe arising from the right lobe. The 10 remaining cases involved variations of intrahepatic portal branching resulting from absence of the right portal vein, taking four patterns. It is thought that these findings represent variants of normal. These variants are important in two settings: in planning hepatic surgery and in the differential diagnosis of chronic portal vein thrombosis.

Adult↗

PubMed1990

Incidence of portal vein thrombosis complicating liver metastasis as detected by duplex ultrasound.

In a prospective study of 100 patients with liver metastasis using real-time ultrasound, 8 patients (8%) were found to have portal vein thrombosis (PVT). Sixty seven of these patients, which included all with PVT, also underwent duplex examination. Pulsed Doppler showed absent flow in 4 of 8 patients, indicating complete obstruction. The other 4 showed different degrees of flow suggesting incomplete obstruction or collateral formation. We conclude that PVT complicating liver metastasis is not a rare finding.

Adult↗

PubMed1990

Interobserver variability in the interpretation of contrast venography, technetium-99m red blood cell venography and impedance plethysmography for deep vein thrombosis.

Contrast venography (CV) is the standard technique for diagnosing deep vein thrombosis (DVT). Newer noninvasive tests have also proven efficacious. However, there is a lack of data on the level of agreement among observers in their interpretation of the results of the various tests. After agreeing on well-defined criteria, three experienced observers assessed, blindly, the results of tests performed over a 4-month period on 117 patients who were suspected clinically of having had a first episode of DVT. The kappa statistic was used to measure the level of agreement beyond chance for CV (69 patients), red blood cell venography (RBCV) (82 patients) and impedance plethysmography (76 patients). The results of CV were assigned to normal, abnormal or inadequate categories, and those of RBCV and IPG to normal, equivocal or abnormal categories. The kappa values for CV, RBCV and IPG ranged from 0.53 to 0.56, 0.42 to 0.56 and 0.90 to 0.91 respectively. Values greater than 0.75 represented excellent agreement beyond chance and those between 0.40 and 0.75 represented fair to good agreement. Excellent kappa values were obtained for IPG because interpretation of the results of this method is entirely objective. Although the values for CV and RBCV showed good to fair agreement, there was a greater degree of observer variation, despite the well-defined criteria, indicating the subjectivity of interpretation of these test results. It is concluded that the kappa statistic can be used to measure observer variation of the results of tests for diagnosing DVT and may serve as a quality control tool for studies in which more than one person interprets the results.

Contrast Media↗

PubMed1989

Why is the lower torso protected in traumatic asphyxia? A new hypothesis.

Traumatic asphyxia secondary to a crush injury of the chest is characterized by craniocervical cyanosis, subconjunctival hemorrhage, and severe vascular engorgement of the head and neck. These signs are believed to be due to high venous pressures causing stasis and capillary rupture. A "fear response" that produces a strong Valsalva maneuver is thought to be necessary for their development. The lower torso seems to be protected, and previously this was thought to be due to its superior system of valves. We present here ultrasonographic evidence that the inferior vena cava is compressed or obliterated during a Valsalva maneuver, and propose that this compression protects the lower torso during traumatic asphyxia.

Abdomen↗

PubMed1989

Interventional uroradiology.

Major interventional uroradiologic techniques including percutaneous nephrostomy, vascular augmentation and reduction procedures, percutaneous cyst aspiration, chronic peritoneal dialysis catheter manipulation and urethroplasty are reviewed. A brief history of the development and techniques for performing these procedures are included. The results of clinical series are assessed and their role in patient management is addressed. The development of these procedures has had a significant impact on patient care by providing effective nonoperative therapy.

Angioplasty, Balloon↗

PubMed1989

Treatment of pleural effusions and pneumothorax with catheters placed percutaneously under imaging guidance.

We analyzed our experience with 42 consecutive patients who had pleural effusions (seven benign exudates, 12 malignant exudates, and 15 empyemas) or pneumothoraxes (eight patients) treated over a 3-year period by catheters placed percutaneously under imaging guidance. The catheters ranged in size from 8 French to 14 French. Although the overall success rate was 71% (30/42), the success rate during the first 2 years was 57% (12/21), compared with 86% (18/21) during the third year. The success rates according to collection type were 63% (12/19) for exudates, 80% (12/15) for empyemas, and 75% (6/8) for pneumothoraxes. There were two complications: a vasovagal reaction and a sterile collection converted to an empyema. After an initial learning period and with accumulated experience, radiologically placed catheters have proved to be an efficacious treatment of pleural effusions and pneumothoraxes that has a low complication rate.

Adult↗

PubMed1988

Gastric adenocarcinoma: CT versus surgical staging.

Seventy-five patients with gastric carcinoma underwent preoperative staging with computed tomography (CT). In 14 patients, CT failed to demonstrate lymphadenopathy despite the presence of malignant lymph nodes at surgery. In 13 patients, CT demonstrated enlarged nodes, but no malignant involvement was found at surgery. Although spread to the pancreas was correctly predicted in three patients with lack of fat plane between tumor and pancreas, five patients lacking a fat plane had no invasion, whereas eight patients with an intact fat plane had invasion. Thirty-five patients (47%) were incorrectly staged with CT:23 (31%) were understaged and 12 (16%) were overstaged. CT does not accurately display the true extent of disease in patients with gastric carcinoma and therefore should not be used routinely for staging.

Adenocarcinoma↗

PubMed1988

Intrahepatic bile duct and portal vein anatomy revisited.

Seventeen normal cadaver livers were studied to assess the anatomic relationship of bile ducts to portal veins. The common bile duct, main portal vein, and hepatic artery were cannulated and injected with air, dilute contrast medium, and mineral oil, respectively. The livers were placed in anatomic position and examined with computed tomography. In the lateral segment of the left hepatic lobe, the bile ducts were anterior to the portal vein in seven cases, posterior in seven, and tortuous (ie, both anterior and posterior) in three. In the medial segment of the left lobe, the bile ducts were anterior in four cases, posterior in four, tortuous in three, and not seen in six. In the right lobe, the bile ducts were anterior in nine cases, posterior in five, tortuous in one, and not seen in two. In the porta hepatis, the bile ducts were anterior in ten cases, posterior in one, tortuous in five, and not seen in one. Histologic findings confirmed the anterior and posterior location of the bile ducts relative to the portal veins. These findings contradict the commonly held view of intrahepatic bile ducts being anterior to the portal vein and are clinically significant for techniques such as bile duct drainage.

Adult↗

PubMed1988

Hepatic malignancies: improved treatment with intraarterial Y-90.

An improved treatment method for hepatic malignancies with yttrium-90 incorporated into the matrix of glass microspheres was evaluated prospectively. Fifteen patients with 12 metastatic colorectal cancers, one carcinoid, one islet cell tumor, and one hepatoma were treated with three dose levels: 5,000 cGy (5,000 rad), ten patients; 7,500 cGy (7,500 rad), three patients; and 10,000 cGy (10,000 rad), two patients. Mean follow-up was 7 months (range, 2-12 months). Stable disease in the liver was seen in ten patients, four of whom had concurrent progression of extrahepatic disease, which resulted in two deaths. Two additional deaths were not directly related to the malignant process. Progression of liver disease was found in five patients, with three deaths occurring at 7-8 months. No procedural, hematologic, or pulmonary complications occurred. Late gastroduodenal ulceration occurred at 6-8 weeks in three patients who had histories of chronic alcohol abuse. This method of therapy seems to be feasible and efficient. Caution is necessary with high doses or with patients with a history of or predisposition to gastroduodenal ulcers.

Aged↗

PubMed1988

Fibromuscular dysplasia of renal arteries: comparison of intravenous digital subtraction angiography with conventional angiography.

Intravenous digital subtraction angiography (IV-DSA) was compared with conventional arteriography (CA) in 14 patients with fibromuscular dysplasia (FMD) of at least one renal artery. IV-DSA identified 29 of the 34 renal arteries detected by CA. A diagnostic quality IV-DSA examination was obtained in 23 of 29 renal arteries (78%). In adequately imaged renal arteries, IV-DSA correctly identified 12 of 20 FMD renal arteries, misdiagnosed 8 FMD renal arteries as normal and correctly identified 3 normal renal arteries. These poor results, due to poor spatial resolution and subtraction artifacts inherent in the IV-DSA system, warrant careful interpretation of negative examinations and further evaluation of high risk patients.

Angiography↗

PubMed1988

Sonographic diagnosis of isolated gallbladder trauma.

We report a patient with isolated post-traumatic injury to the gallbladder diagnosed preoperatively by ultrasonography. Demonstration of echogenic, nonshadowing, mobile material in the gallbladder should suggest this diagnosis. Early diagnosis is essential because, unlike other abdominal organ injuries which may be managed conservatively, injury to the gallbladder requires surgery.

Adult↗

PubMed1987

Digital intravenous subtraction angiography in the evaluation of reconstructed renal arteries.

Digital intravenous subtraction angiography (DISA) was used to evaluate 28 patients who had undergone renal artery reconstruction either as part of a renal transplant procedure or for treatment of renovascular hypertension. Satisfactory visualization of the renal artery was obtained in 26 cases, and the clinical questions were adequately answered in these cases. The findings included a variety of possible outcomes and demonstrate the adequacy of DISA as a means of evaluating the results of renal artery surgery. Technical and anatomic factors affecting the quality of the examination are discussed. The cases also illustrate the critical importance of thorough familiarity with the surgical procedures in general and of mutual discussion between surgeon and radiologist in optimizing the DISA examination in a given patient.

Adult↗

PubMed1987

Angelchik antireflux device: computed tomography appearance.

The Angelchik antireflux prosthesis is a silicon gel-filled, doughnut-shaped device with a tantalum tie strap that wraps around the gastroesophageal junction after reduction of a hiatal hernia. If dislodged, this prosthesis may produce a confusing picture on computed tomography, as it is of soft tissue density and may mimic a mass lesion. The computed tomography appearance of a normally placed prosthesis is demonstrated, and a case of prosthesis dislodgment diagnosed by computed tomography is reported.

Adult↗

PubMed1987

Intravenous digital subtraction angiography in the evaluation of potential renal donors.

Of 65 surgically removed donor kidneys intravenous digital subtraction angiography demonstrated accurately the number of renal arteries in 58 (89 per cent). All accessory vessels missed at digital subtraction angiography were small and their presence did not interfere with successful transplantation in those donated. Of 50 surgically removed donor kidneys examined with conventional aortography only before the routine use of intravenous digital subtraction angiography the number of renal arteries was demonstrated accurately in 46 (92 per cent). Intravenous digital subtraction angiography offers advantages over conventional aortography, including most importantly the routine performance on an outpatient basis, and decreased film cost and examination time. Although the accuracy of conventional aortography (92 per cent) in detecting the number of renal arteries is slightly greater than that for intravenous digital subtraction angiography (89 per cent), the advantages of the digital examination justify its use as the initial examination for the potential renal donor. Conventional aortography can be reserved for use in patients with equivocal or technically inadequate digital examinations.

Angiography↗