Search PubMed⌕ Search

Biomedical subjects

J R Haaga

Publications and source records attributed to J R Haaga.

At least 37 records · Page 2Linked to original sources
PubMed1993

Fluid flow during percutaneous drainage procedures: an in vitro study of the effects of fluid viscosity, catheter size, and adjunctive urokinase.

OBJECTIVE: An in vitro study was performed to determine the range of flow times of different bodily fluids through catheters of different diameters and to test the hypothesis that urokinase might decrease the viscosity of purulent material. MATERIALS AND METHODS: A standard viscometer was used to measure the viscosities of water, blood, pseudocyst fluid, purulent material, and purulent material with admixed urokinase. For each fluid, Poiseuille's law was used to calculate the kinematic viscosity, from which theoretical drainage times through seven different sizes of catheters were calculated. These theoretical times were compared with the actual measured values to verify that flow was according to Poiseuille's law. RESULTS: The calculated kinematic viscosities (in 10(-6) stokes) were as follows: water, 0.695 +/- 0.006; pseudocyst fluid, 2.185 +/- 0.008; blood, 3.001 +/- 0.049; abscess fluid without urokinase, 5.729 +/- 0.064; and abscess fluid with urokinase, 4.416 +/- 0.070. The viscosity of abscess fluid decreased by 23% with the addition of urokinase. Drainage time was considerably shorter with larger catheters. CONCLUSION: Flow of various bodily fluids, including pus, is according to Poiseuille's law, confirming that for more viscous fluid, larger catheters provide more rapid drainage. Urokinase decreases viscosity of purulent material and increases flow for all sizes of catheters.

Abscess↗
PubMed1993

Safety of intracavitary urokinase with percutaneous abscess drainage.

OBJECTIVE: Percutaneous drainage of abscesses is an effective treatment, but the success rate is lower for abscesses that have septa and are multilocular. Several clinical and in vitro studies suggest urokinase may be useful in such cases. Our study was designed to determine the safety of urokinase administered into an abscess cavity during the course of percutaneous drainage. SUBJECTS AND METHODS: Our study included 26 consecutive patients with 31 abscesses treated with percutaneous drainage. Exclusion criteria included age less than 18 or more than 95 years, CNS disorders (e.g., tumor, vascular problems), coagulation impairments, hepatic failure, pregnancy, and abscesses in the spleen, pancreas, or interloop area. Three doses were used: group 1 (nine patients), 1000 IU of urokinase per centimeter of abscess diameter; group 2 (11 patients), 2500 IU of urokinase per centimeter of abscess diameter; and group 3 (nine patients), 5000 IU of urokinase per centimeter of abscess diameter. These doses were administered every 8 hr for 3 days along with percutaneous drainage. Charts were reviewed to determine success and to detect adverse clinical events. Studies included sequential CT scans; serial serum determinations of hematocrit, prothrombin time, partial thromboplastin time, platelet count, fibrinogen levels, and levels of fibrin degradation products; and serial laboratory analysis of purulent material for fibrinogen and fibrin degradation products. Percutaneous drainage was considered successful if no surgical intervention was required. RESULTS: Our results showed no significant change in hematologic studies and no bleeding complications. Analysis of purulent material indicated that urokinase remained active in the abscess milieu. Drainage was successful in seven of 11 patients in group 1, all nine patients in group 2, and 10 of 11 patients in group 3. All eight abscesses with septa were successfully drained. CONCLUSION: Intracavitary urokinase can be given safely during percutaneous drainage of an abscess, with no associated bleeding complications or changes in coagulation parameters.

Abscess↗
PubMed1992

Effect of needle gauge, level of anticoagulation, and target organ on bleeding associated with aspiration biopsy. Work in progress.

Percutaneous fine-needle aspiration biopsy has gained wide acceptance due to its accuracy, ease of performance, and safety. This study was performed to evaluate the effect of needle size, coagulation impairment, or biopsy of different organs on risk of bleeding during the procedure. Multiple biopsy procedures were performed on the livers and kidneys of anesthetized pigs with 14-22-gauge Chiba-type needles. The procedures were performed under direct vision at laparotomy, and blood loss was measured. While larger needles generally produced more bleeding, the differences were statistically significant only when comparing 14- with 16-gauge needles and 16-gauge needles with the group of 18-, 20-, and 22-gauge needles in the liver. In the kidney, no significant difference was noted between 18-, 20-, and 22-gauge needles. Anticoagulation did not produce significantly greater blood loss but did allow separation of the group of 18- and 20-gauge needles from 22-gauge needles in the kidney. Renal biopsy resulted in greater overall blood loss than did liver biopsy.

Animals↗
PubMed1992

Hepatic neoplasms: surgically relevant segmental anatomy and imaging techniques.

With advances in imaging and surgical techniques, the diagnosis and treatment of primary and secondary liver neoplasms have improved. Advances in imaging have contributed to the early detection of the tumors and have allowed more precise preoperative characterization and localization of the lesions. Refinements in surgical technique have permitted more extensive resections, while at the same time placing even greater importance on accurate preoperative imaging of the tumor. Presurgical planning requires precise definition of the extent of the tumor vis-à-vis hepatic segmental anatomy. The goal of this essay is to discuss the segmental anatomy of the liver, the types of segmental resections possible, and the strengths and weaknesses of the various imaging techniques used in the preoperative assessment of potential candidates for hepatic resection. Staging of hepatic malignant tumors and technical details of the imaging techniques are not discussed.

Diagnostic Imaging↗
PubMed1991

Pelvic abscesses: CT-guided transrectal drainage.

Percutaneous drainage of pelvic abscesses has been performed by using a number of approaches, including transabdominal, transgluteal, and transrectal. The authors present a technique for the drainage of pelvic abscesses by a transrectal route with use of computed tomographic (CT) guidance. Equipment for the technique included a plastic introducer tube, standard needle, angiographic guide wire, and pigtail catheters. The pelvic abscesses of 10 patients (six after appendectomy, three after colon resection, one secondary to diverticulitis) were successfully drained by using the new technique. No complications or recurrences were experienced. After initial catheter placement, patients were treated with use of gravity drainage and appropriate antibiotics. Success of drainage was determined with sequential CT scans. Compared with the transgluteal approach, the transrectal approach offered increased patient comfort and minimal risk of potential complications such as injury to the sciatic nerve or tracking of the abscess. Use of the plastic introducer tube promoted operator safety by protecting the guiding finger. On the basis of this initial series, CT-guided transrectal drainage appears to be an effective and well-tolerated method for the drainage of pelvic abscesses.

Abscess↗
PubMed1991

Imaging-guided percutaneous abdominal biopsy.

Guided percutaneous biopsy has become an important means of diagnosing abdominal lesions. This technique provides necessary pathologic information without resorting to open biopsy. Fluoroscopy, sonography, computed tomography or magnetic resonance imaging may be used for needle guidance, depending on the patient's condition and the size and location of the lesion. These variables also influence selection of needle gauge, tip configuration, and sampling mechanism. The authors describe appropriate techniques for percutaneous biopsy of hepatic, renal, pancreatic, adrenal, and retroperitoneal lesions.

Abdominal Neoplasms↗
PubMed1990

Hemostatic protein-polymer sheath: new method to enhance hemostasis at percutaneous biopsy.

Serious hemorrhagic complications have been reported with percutaneous biopsy, albeit infrequently. A hemostatic protein-polymer sheath (PPS) designed to limit the risk of bleeding was evaluated by performing liver biopsies on pigs given anticoagulants. After administration of anesthesia and laparotomy, biopsies were performed under direct vision with a cutting biopsy needle (a) alone, (b) fitted with the PPS, or (c) fitted with a thrombin-coated PPS. Dry sponges were applied and subsequently weighted to quantitate blood loss. At all levels of anticoagulation, use of the PPS enhanced hemostasis; the thrombin coating supplemented effectiveness. The PPS appears to be a simple and effective method of achieving hemostasis at high-risk percutaneous biopsy.

Animals↗
PubMed1989

Staging renal carcinoma. What is sufficient?

We retrospectively reviewed the roentgenographic and pathologic staging of 64 patients with renal cell carcinoma to assess the role of the various staging modalities (ie, angiography, venacavography, bone scanning, ultrasound, computed tomography [CT], and magnetic resonance imaging). Specific attention was directed at detecting vena cava thrombus and metastatic bone disease, factors with a significant impact on the therapeutic approach. The findings support the role of CT as the principle tool for overall staging and the observation that venacavography is not indicated if CT has excluded caval thrombus. Similarly, routine bone scans are not warranted in the absence of an elevated alkaline phosphatase level or bone pain. The key to the more efficient utilization of imaging resources is understanding the capabilities of the technology available.

Adult↗
PubMed1988

CT-guided cutting-needle biopsies of selected chest lesions.

In an effort to improve on our diagnostic yield from percutaneous transthoracic biopsy, we used 14-gauge cutting needles in 56 selected patients. These biopsies were preceded by 18-, 20-, or 22-gauge aspirations in 42 patients, allowing a direct comparison of the efficacy of the needle types. Specific diagnoses were made by cutting-needle biopsy in 78% (25/32) of patients with nonlymphoproliferative malignancies, in 73% (8/11) with lymphoma or thymoma, and in 54% (7/13) of patients with benign diseases. In those in whom both aspiration and cutting needles were employed, a higher percentage of specific diagnoses was achieved by cutting-needle biopsy than by aspiration biopsy: 72% vs 64% in nonlymphoproliferative malignancies, 62% vs 12% in the lymphoproliferative group, and 55% vs 22% in benign disorders. Complications were encountered in 20% of all patients studied. This study shows that, for selected chest lesions, CT-guided cutting-needle biopsies can be performed safely and are useful, especially in the diagnosis of lymphoproliferative or benign disease.

Adolescent↗
PubMed1988

[Fine needle biopsy of the pancreas with computerized tomography control].

The results of 96 computed tomography guided percutaneous pancreatic aspiration biopsies were reviewed and compared with the findings at laparotomy or autopsy or with a follow-up of at least one year. In only four instances the follow-up was inadequate and in 29 cases the specimen did not allow a cytologic or histologic diagnosis. Of the remaining 67 biopsies 65 were diagnosed correctly and only 2 incorrectly. This corresponds to a sensitivity of 67.7% and a specificity of 97%. In patients with primary pancreatic cancer the figures for sensitivity or specificity are 76.8% and 97.3% respectively. We did not observe any serious complications. Only one patient had a transient rise of the serum amylase. We believe that the percutaneous aspiration biopsy of the pancreas guided by computed tomography is a safe and effective method in the histologic and cytologic diagnosis of pancreatic lesions.

Biopsy, Needle↗
PubMed1987

CT-guided percutaneous catheter cecostomy.

A patient with pseudomembranous colitis is described in whom a percutaneous cecostomy was performed using computed tomographic guidance. Several lines of evidence indicate the safety of this approach, and clinical circumstances are suggested in which the procedure may have potential therapeutic benefit.

Aged↗
PubMed1986

The utility of computed tomography in colonic diverticulitis.

Forty-one patients admitted to our hospital during an 18-month period with the clinical diagnosis of colonic diverticulitis were analyzed to evaluate the utility of computed tomography (CT). Abdominal pain and leukocytosis were the most common presenting manifestations, 75 and 66%, respectively. Just over one-half of the patients also demonstrated hematuria. Twenty patients required surgical intervention, most commonly for failure to improve despite medical management. Preoperative studies included 10 sigmoidoscopies, 30 plain abdominal roentgenograms, 20 barium enemas (BE), and 24 CT scans. Two CT scans were also obtained after operation for successful percutaneous drainage of intra-abdominal abscesses. Abdominal roentgenograms were most commonly obtained but least helpful, with only one third demonstrating any abnormality whatsoever. Sigmoidoscopy was least commonly performed but almost universally abnormal. Specificity was low, however, in that spasm with inability to advance the endoscope was the most common finding. Of the 20 barium enemas obtained, 60% had findings consistent with diverticulitis, most commonly localized perforation or fixed narrow segment. Sixty-three per cent of CT scans were abnormal. The most frequent findings were localized thickening of the colonic wall and increased density in the pericolic fat. Diverticular abscess, which may be inferred by other studies, was definitely diagnosed in one third of the patients with abnormal CT scans. CT also provided the ability to identify extracolonic intra-abdominal pathology. The study demonstrates that both barium enema and CT are effective in diagnosing diverticulitis, although CT can be performed without risk. CT played no therapeutic role before operation, although two patients benefited after operation by CT-guided drainage of intra-abdominal abscesses. The decision for surgery was most frequently dependent on clinical examination and never solely on the basis of either the barium enema or CT in this study. The major benefit of CT appears to be its ability to identify both gross and subtle changes indicative of diverticular disease and extracolonic pathology in a relatively noninvasive manner.

Adult↗
PubMed1986

Use of CO2 to move structures as an aid to percutaneous procedures.

By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6).

Aged↗
PubMed1986

Magnetic resonance imaging of the prostate.

The prostate was examined by magnetic resonance imaging (MRI) in 33 subjects, including five normal volunteers, 18 with prostatic carcinomas, seven with benign nodular hyperplasias, two cases of acute prostatitis, and one case of chronic prostatitis. Of 18 prostatic carcinomas, 16 produced an inhomogeneous signal intensity, with areas of diminished signal on T1-weighted scans and usually increased signal on T2-weighted images relative to the rest of the prostate. However, a similar appearance was also seen in five cases of benign nodular hyperplasia. It is doubtful at present whether MRI is able to reliably differentiate benign from malignant prostatic disease. Extraprostatic tumor extension and pelvic adenopathy was well shown, and MRI is very promising as a method for the preoperative staging of known prostatic carcinomas.

Carcinoma↗
PubMed1986

Evaluation of computed tomography guided percutaneous biopsy of the pancreas.

The results of 96 computed tomography guided percutaneous pancreatic aspiration biopsies were reviewed to evaluate the diagnostic sensitivity, specificity and accuracy in pancreatic mass lesions. These were assessed by comparing pathology results to findings at subsequent laparotomy, autopsy or to immediate and long term clinical findings. Effects of varying the size of the biopsy needle and the number of aspirations performed were examined. Of the primary tumors of the pancreas in which adequate material was obtained, 97.3 per cent were correctly diagnosed with one false-negative and no false-positive results. The over-all sensitivity rate for primary tumor so the pancreas was 71.9 per cent using a No. 22 gauge "skinny" needle and 86.7 per cent using a No. 20 gauge needle. Over-all diagnostic accuracy for all types of lesions was 61.8 per cent using a No. 22 gauge needle and 73.3 per cent using a No. 20 gauge needle. A No. 19 gauge needle with a sheath was used on lesions with fluid or necrotic debris when a pseudocyst was a possibility. Over-all diagnostic accuracy using a No. 19 gauge sheathed needle was 81.8 per cent on all types of lesions. There was no benefit in using two passes versus a single aspiration. There were no complications, regardless of the needle size or number of passes. The serum amylase level increased in one instance after biopsy and this returned to normal a few days after biopsy. Computed tomography guided aspirations are safe and effective in evaluation of focal or diffuse enlargements of the pancreas when proper techniques and appropriate precautions are used.

Biopsy, Needle↗