Biomedical subjects
Publications and source records attributed to L Machan.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Except for choice of embolization agent, the technique of uterine artery embolization for the treatment of fibroids is similar to that performed as emergent therapy for hemorrhage. The unique and more difficult aspects of fibroid embolization relate to patient recruitment and periprocedural care. There are few procedures in interventional radiology where timely and thoughtful pre- and postprocedure care are as important to building a practice. This is because of the intense and often prolonged clinical consequences of fibroid embolization, the attitude of many gynecologists toward interventional radiology and interventions for fibroids and especially because of the patient demographic. Patients seeking fibroid embolization tend to be highly motivated, educated women in their 20s to 40s with Internet access. The interventional radiologist unable to provide adequate answers or time to this group of patients in particular will find that they are an unforgiving lot!
Explore the source record for details and available documents.
OBJECTIVE: The value of echo-enhanced color and power Doppler sonography in the evaluation of transjugular intrahepatic portosystemic shunts (TIPS) was assessed and compared with that of unenhanced Doppler sonography and portal angiography. SUBJECTS AND METHODS: In a prospective randomized trial, 31 shunts in 30 patients underwent unenhanced conventional color and power Doppler sonography and portal venography including pressure measurements. The patients were allocated to either echo-enhanced conventional color Doppler sonography or echo-enhanced power Doppler sonography. For echo enhancement, a galactose-based suspension was administered IV. Shunt stenoses, if present, were quantified by percentage of stenosis and correlated with angiography, which was the gold standard. The diagnostic confidence of unenhanced and echo-enhanced Doppler sonography was assessed using a visual analog scale. RESULTS: In the diagnosis of shunt occlusion, echo-enhanced Doppler sonography yielded a sensitivity and a specificity of 100% and 100%, respectively, compared with 100% and 89%, respectively, for unenhanced Doppler sonography. Our evaluation of hemodynamically significant stenoses (portosystemic gradient > or = 15 mm Hg) found echo-enhanced Doppler sonography to be superior to unenhanced Doppler sonography (sensitivity and specificity of 82% and 83%, respectively, compared with 64% and 80%, respectively). In the detection of a shunt stenosis based on morphologic criteria only, echo-enhanced Doppler sonography yielded a sensitivity and a specificity of 78% and 100%, respectively, compared with 47% and 50%, respectively, for unenhanced Doppler sonography. Power Doppler imaging did not improve diagnostic accuracy but did increase diagnostic confidence for unenhanced Doppler sonography compared with conventional color Doppler sonography. The diagnostic confidence for sonographic evaluation of TIPS was significantly (p < .001) increased and the variability of hemodynamic measurements was markedly decreased with echo-enhanced sonography. CONCLUSION: Echo-enhanced Doppler sonography provides images of TIPS like those of angiography and allows morphologic assessment of the shunts, complementary to the essential pulsed Doppler waveform analysis that would be performed in a more guided manner. Also, echo-enhanced Doppler sonography significantly increases the sensitivity and specificity in the diagnosis of shunt dysfunction. The high diagnostic confidence and the diminished variability of spectral Doppler measurements may improve acceptance of sonographic evaluation of TIPS. Echo-enhanced Doppler sonography is safe and effective and may reduce the instances in which TIPS sonographic surveillance is nondiagnostic, in which case angiographic assessment is required.
Local application or direct tumor injection of chemotherapeutic drugs has been proposed as a method by which local drug concentrations can be maximized in the immediate tumor environment while systemic exposure and non-target organ toxicity is minimized. Multiple opportunities are available to combine local drug delivery with widely practised, existing medical and surgical therapies. Surgical interventions, including both open and laparoscopic procedures, allow the physician to directly visualize and manipulate pathological tissues. Intraoperative placement of implantable therapeutic compounds (barriers to prevent adhesions, sustained-release antibiotics, tissue 'glues' and hemostatic agents) at or near the disease site is increasingly common in surgical practice. Less invasive therapies assisted by diagnostic imaging (fluoroscopy, ultrasound, CT and MRI scanning) have made accurate needle or catheter placement for drainage (abscesses, cysts, obstructions), injection (contrast media, pharmacological agents, embolic agents) and therapeutic purposes (endoluminal stents, venous filters) widely practised interventional medical procedures. This article describes a chemotherapeutic polymer-based paste we have developed for application at the time of surgery to reduce local recurrence of disease at tumor resection sites and a chemotherapeutic polymer-coated stent for use in the palliative management of malignant obstruction to improve the effective lifespan of the device (e.g., esophageal, biliary, prostate, and pulmonary disease). Despite the growth of local therapy in other disease states, regional cytotoxic drug therapy has not been widely deployed in the management of malignancy due to a clinical bias that local therapy will have limited utility in what is considered to be a systemic disease. In the above manner, local drug delivery could be incorporated into therapeutic protocols designed to enhance, not replace, the efficacy of existing treatment options.
BACKGROUND: Peritoneal tumor dissemination and implantation is a complication of both open and laparoscopic oncologic surgery. This study evaluates the efficacy of paclitaxel-loaded poly(L-lactic acid) microspheres as prophylaxis against intraabdominal tumor seeding. METHODS: 2 x 10(6) 9L glioblastoma cells were introduced into the abdominal cavity of Wistar rats. Fifteen minutes later, the peritoneal cavity was washed with the experimental solutions, and 2 weeks later the presence of tumor implantation was determined. After defining the optimum dose of paclitaxel PLA microspheres in a dose-ranging study, the microsphere formulation was then compared with conventional paclitaxel in four experimental groups (n = 5) as follows: 100 mg of 30% paclitaxel-loaded microspheres; 100 mg PLA microspheres; paclitaxel 4.1 mg; and controls receiving no intraabdominal therapy. RESULTS: Although carcinomatosis developed in all control animals, none in the paclitaxel-loaded microsphere group had biopsy proven cancer. The conventional paclitaxel group (3) showed significant toxicity; only 1 animal survived and had positive histology. CONCLUSIONS: In this animal model of peritoneal carcinomatosis, the paclitaxel-loaded microsphere formulation was more effective than conventional paclitaxel in preventing tumor seeding.
PURPOSE: To determine interobserver variability in the morphometric measurement of abdominal organs with US and spiral CT, and to compare the results obtained with these two modalities. MATERIAL AND METHODS: US and spiral CT examinations of the abdomen were performed in 25 patients. In each patient, 13 defined distances were measured in the liver, spleen and both kidneys with US and spiral CT by two pairs of radiologists in a blinded manner. The interobserver variations of these measurements were evaluated for the US and CT examinations, and the data of both modalities were compared with one another. RESULTS: The measurement of distances in the abdomen with US and spiral CT is subject to considerable interobserver variability in both modalities. The relative interobserver variations showed marked differences, according to which distance was measured. The average interobserver variations were higher in US than in CT. A direct comparison of US and spiral CT revealed that distances obtained with CT frequently exceeded those obtained with US. CONCLUSION: Morphometric measurements of abdominal organs with US and with spiral CT showed considerable differences. The follow-up examinations should therefore be performed with the same imaging modality as used in the original examination.
The authors evaluated the results after classical (CCHE) and laparoscopic cholecystectomies (LCHE) in the period from March 16 1994 to June 30 1995. In this period they operated on 408 patients, out of which 208 were operated by the laparoscopic technique. There were no differences in postoperative morbidity. The mortality after laparoscopic surgery was 0% and the classical cholecystectomy reached the morbidity of 1.4%. Complicated patients were usually operated in the classical way. The time of hospitalisation after LCHE was 5.2 days and after CCHE 8.3 days. The results of LCHE were as follows: morbidity 10.5%, conversions 2.4%, reoperations 1.4%, and no leakage of the bile duct. We saved 40% of costs using LCHE. All these facts show that LCHE is advantageous, secure and well tolerated by patients. The patients prefer comfort after the operation, good cosmetic effect and a short hospital isation. CCHE did not lose its position, especially in complicated cases. (Tab. 5, Ref. 21.)
Small bowel diverticulosis is a rare disease of gastrointestinal tract that occurs most frequently in older patients. Since this disease can be asymptomatic, for a long time, the diagnosis rarely is made in the preoperative period. In 40% of cases there are acute or chronic complications, most frequently diverticulitis either with or without perforation, bowel obstruction and massive haemorrhage clinically manifested as bleeding from the lower part of the gastrointestinal tract. Abdominal pain, pseudoobstructive and malabsorption syndrome, expressive weight loss, steatorrhea and anemia are common chronic complications. In these cases a surgical treatment is necessary. Resection of the affected part of the small bowel is usually performed with end-to-end anastomosis. The authors present 4 cases with diverticulosis of the small bowel, two cases of which were manifested by diverticulitis and one of them was perforated. Pseudoobstructive syndrome, malabsorption and expressive weight loss were presented in other two cases. All four cases were dominated by severe abdominal pain. The surgical treatment was based upon radical resection of the small bowel with end-to-end anastomosis. (Fig. 4, Ref. 28.)
Some of the effects on blood and contrast agents of a laser angioplasty device of the "hot tip" variety have been studied. This device liberates iodine from contrast agents both in the form of soluble free iodide and in the form of solid elemental iodine debris. Some of the solid iodine does not adhere to the probe but remains free and, in vivo, would be available to embolize distal vessels. The liberation of iodine occurs more readily with dimeric agents than with monomeric contrast agents regardless of whether they are ionic or non-ionic. Blood and blood/contrast agent mixtures exhibit local boiling in the vicinity of the hot tip laser probe. Blood so treated exhibits markedly accelerated clotting as indicated by measurements of whole blood clotting times. Untreated blood to which aliquots of blood treated as described above are added also exhibits accelerated clotting. The laser tip, operating in blood/iodine mixtures, becomes coated with a friable black/brown deposit which analysis reveals to be a mixture of carbon and iodine. Again, some of this particulate debris fails to adhere to the probe and is available as free embolic material. The possible practical clinical implications of these observations are discussed.
The authors evaluated their 15-year experience with revascularization operations for atherosclerosis obliterans (ASO) of the lower extremities. Over the period from 1975 to 1990, 1112 patients with ASO were admitted to their department and in 674 (60.6%) of them revascularization operation was performed. Direct revascularization surgery (bypass, desobliteration, angioplasty) was performed in 318 (47.2%) patients and indirect revascularization, sympathectomy in 326 (52.8%) patients. On evaluating the long-term results of aortobifemoral (AF2), femoropopliteal (FP) and femorocrural (FC) bypasses the following long-term patency was established: AF2 bypass--patency up to 2 years 92%, up to 5 years 90%, up to 10 years 76%, up to 15 years 75%; FP bypass--patency up to 2 years 90%, up to 5 years 84%, up to 10 years 62%, up to 15 years 46%; FC bypass--patency up to 2 years 63%, up to 5 years 50%, up to 10 years 25%. Complications developed in 10%, the mortality rate was 2.5% and 8% in FP and AF2, respectively. The obtained results are comparable with the data published in the literature. The authors achieved the best results in the suprainguinal region with AF2 bypasses on using mostly dacron prostheses and in the infrainguinal region FP bypasses on using the autologous great saphenous vein. (Tab. 3, Fig. 4, Ref. 17.)
Twenty-one patients with prostatic urethral obstruction who were unfit for surgery were treated with self-expandable stainless steel endoprostheses inserted under fluoroscopic guidance. The procedure was technically successful in all patients, although in one case a second stent was required 2 months later. One patient developed a urethral stricture in the 12-16 month follow up period. One case of epididymoorchitis and one case of septicaemia after stenting were treated successfully with antibiotics. Endoprostheses represent a satisfactory alternative to prostatectomy in high-risk patients.
Spurting of blood from standard arterial needles during guide-wire insertion can be controlled easily with a syringe and a simple needle inserted along the syringe plunger. With this method, blood droplets that may be infected with the hepatitis or human immunodeficiency virus will not come into contact with the head and neck of the angiographer or interventional radiologist.
Traumatic ruptures of the diaphragm occur most frequently at blunt injuries of the abdomen or thorax as a component of polytraumatism. At the acute stage they present a serious diagnostic problem since signs of polytrauma are predominant. The authors report 3 cases of traumatic rupture of the diaphragm with thoracotomy as the therapeutic approach. The first patient presented with severe polytraumatism and shock, rupture of the diaphragm, pericardium and lungs, along with serial fracture of the left ribs. The second patient was not in shock, he had suffered serial fracture of the left ribs and fracture of the pelvis. In both these cases of blunt injury to the thorax, careful examination of the patients resulted in early diagnosis and surgery. The third patient presented with open injury of the right side of the thorax, injured diaphragm and liver, serial fracture of the ribs, fractured sternum, and was in a state of deep shock. There was no mortality, all three patients recovered.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A 47-yr-old male with known Crohn's disease involving the third and fourth part of the duodenum and terminal ileum presented to hospital with nausea and vomiting due to duodenal obstruction. An upper gastrointestinal series revealed a clinically unsuspected fistula joining the duodenum and pancreatic duct. He subsequently underwent vagotomy and gastroenterostomy to bypass the obstructed segment of duodenum. The duodenopancreatic fistula was not disturbed. Post-operatively, his symptoms resolved, he gained 30 pounds of weight, and manifested no ill effect secondary to the fistula. A repeat upper gastrointestinal series 9 months postoperatively revealed the fistula to have closed, although marked duodenal narrowing remained.