Manuel Viamonte

Quantification of coronary artery calcium using ultrafast computed tomography.

Ultrafast computed tomography was used to detect and quantify coronary artery calcium levels in 584 subjects (mean age 48 +/- 10 years) with (n = 109) and without (n = 475) clinical coronary artery disease. Fifty patients who underwent fluoroscopy and ultrafast computed tomography were also evaluated. Twenty contiguous 3 mm slices were obtained of the proximal coronary arteries. Total calcium scores were calculated based on the number, areas and peak Hounsfield computed tomographic numbers of the calcific lesions detected. In 88 subjects scored by two readers independently, interobserver agreement was excellent with identical total scores obtained in 70. Ultrafast computed tomography was more sensitive than fluoroscopy, detecting coronary calcium in 90% versus 52% of patients. There were significant differences (p less than 0.0001) in mean total calcium scores for those with versus those without clinical coronary artery disease by decade: 5 versus 132, age 30 to 39 years; 27 versus 291, age 40 to 49 years; 83 versus 462, age 50 to 59 years; and 187 versus 786, age 60 to 69 years. Sensitivity, specificity and predictive values for clinical coronary artery disease were calculated for several total calcium scores in each decade. For age groups 40 to 49 and 50 to 59 years, a total score of 50 resulted in a sensitivity of 71% and 74% and a specificity of 91% and 70%, respectively. For age group 60 to 69 years, a total score of 300 gave a sensitivity of 74% and a specificity of 81%. The negative predictive value of a 0 score was 98%, 94% and 100% for age groups 40 to 49, 50 to 59 and 60 to 69 years, respectively. Ultrafast computed tomography is an excellent tool for detecting and quantifying coronary artery calcium.

Comparison of serial quantitative evaluation of calcified coronary artery plaque by ultrafast computed tomography in persons with and without obstructive coronary artery disease

Coronary artery calcium indicates atherosclerosis. Ultrafast computed tomography (CT) can noninvasively visualize and quantify coronary calcium, permitting the natural history of calcified plaque to be studied. This pilot study evaluates the ability of ultrafast CT to follow the progression of calcified plaque within the coronary arteries in patients with and without obstructive coronary artery disease (CAD). Twenty-five subjects had serial ultrafast CT scans of the coronary arteries a mean of 406 days apart. Changes in the number of calcific deposits, calcified plaque area and volume, calcium density and total calcium score were measured. In the 20 patients with calcium on the first study, there were statistically significant increases in mean peak CT number, total calcified plaque volume, total calcified plaque area and total calcium score (p less than 0.0001 for all). Subjects with proved obstructive CAD (n = 10) on angiography had a 48% increase in calcified plaque volume compared with 22% in asymptomatic subjects (n = 10). Comparison of serial studies showed that smaller calcific deposits often coalesced into single larger calcific deposits. Ninety-eight percent (235 of 241) of deposits identified on the first study were accounted for on the second study. Patients with obstructive CAD had a higher number of new calcific deposits than did those in the asymptomatic group (55 vs 18, p = 0.058). Serial ultrafast CT accurately tracks the progression of coronary artery calcium. It is a useful technique for assessing changes in calcified plaque formation in both asymptomatic subjects and in patients with obstructive CAD. It may be useful for studying the natural history of CAD and the effects of intervention on the course of CAD.

Portosystemic Communications Studied by Transhepatic Portography

The experience of collecting 120 transhepatic portograms, performed in patients with different degrees of portal hypertension, affords the opportunity for discussing the anatomical and hemodynamic features of portosystemic communications. Multiple pathways of decompression were found. The coronary-gastroesophageal collateral formed pathways in 108 cases, other major collaterals in 41, and minor collaterals in 2. This multiplicity of communications suggests that no one vessel is indispensable as a collateral pathway.

Long-term survival after laparoscopic colon resection for cancer: complete five-year follow-up.

AbstractPURPOSE: The role of laparoscopic surgery in the cure of colorectal cancer is controversial. The aim of this study was to evaluate long-term survival after curative, laparoscopic resection of colorectal cancer. Specifically, we wanted to review those patients who now had complete five-year follow-up. METHODS: One hundred two consecutive patients (March 1991 to March 1996) underwent laparoscopic colon resections for cancer at one institution and now have complete five-year survival data. Charts were retrospectively reviewed and results compared with conventional surgery, i.e., open colectomy at our institution, and with the National Cancer Data Base during a similar time period. RESULTS: Fifty-nine male and 43 female patients with an average age of 70 (range, 34–92) years made up the study. Complications occurred in 23 percent of patients, and one patient died (1 percent). Forty-four laparoscopic right colectomies, 2 transverse colectomies, 36 laparoscopic left or sigmoid colectomies, 15 laparoscopic low anterior resections, and 5 laparoscopic abdominoperineal resections were performed. The average number of lymph nodes harvested was 6.6 ± 0.61 (range, 0–22). Eight cases (7.8 percent) were “converted to open”; i.e., the typical 6-cm extraction site was lengthened to complete mobilization, devascularization, resection, or anastomosis, or a separate incision was required to complete the procedure. There was one extraction-site recurrence and one port-site recurrence; both occurred before the routine use of plastic-sleeve wound protection. The mean follow-up for laparoscopic colon resection patients was 64.4 ± 2.8 (range, 1–111) months. According to the TNM classification system, 27 patients had Stage I cancer, 37 had Stage II, 23 had Stage III, and 15 had Stage IV. Similar five-year survival rates for laparoscopic and conventional surgery for cancer were noted. The five-year relative survival rates in the laparoscopic colon resection group were 73 percent for Stage I, 61 percent for Stage II, 55 percent for Stage III, and 0 percent for Stage IV. The five-year relative survival rates for the open colectomy and National Cancer Data Base groups were 75 and 70 percent, respectively, for Stage I, 65 and 60 percent for Stage II, 46 and 44 percent for Stage III, and 11 and 7 percent for Stage IV. CONCLUSIONS: Laparoscopic colon resection for cancer is safe and feasible in a private setting. Our data suggest that long-term survival after laparoscopic colon resection for cancer is similar to survival after conventional surgery. Prospective, randomized trials presently under way will likely confirm these results.

GUIDED CATHETERIZATION OF THE BRONCHIAL ARTERIES. I. TECHNICAL CONSIDERATIONS.

Selective catheterization of small vascular branches is easily accomplished since the development especially constructed catheters with minute tips, optimal torque control, and tip deflection by external manipulation (5). We have called this technic “guided angiography.” Exploration of the bronchial arteries by this method has been prompted by recognition of the part these small arteries play in diseases of the bronchial tree and mediastinal organs and in abnormalities of the pulmonary arterial circulation. The procedure and preliminary findings in guided catheterization of the bronchial arteries were reported earlier (6). Our experience with a larger group of cases has enhanced our knowledge and technic, and it is the intent of this paper to expand on these technical considerations and mention some of the pitfalls encountered in the procedure and its interpretation. Technical Consderations Despite the variability in number and site of origin (Fig. 1), selective catheterization of bronchial arteries is ea...

SELECTIVE BRONCHIAL ARTERIOGRAPHY IN MAN; PRELIMINARY REPORT.

Since 1963 we have successfully accomplished selective bronchial arteriography in man with percutaneous transfemoral technic and the aid of a specially designed and locally constructed catheter.3 This catheter has extreme maneuverability and controllable deflection of the tip by reason of a deflector assembly. Technic A cannula-trocar set, guide, catheter, and deflector assembly, all locally constructed, are used.3 Following percutaneous transfemoral catheterization of the aorta, the tip of the catheter is positioned just distal to the origin of the left subclavian artery. The patient lies comfortably on a motorized remotely controlled rotating cradle which permits rotation of the patient from 0 to 90° to either side at variable speeds any time during the procedure. The wire of the deflector assembly is retracted, and this allows bending of the preformed curved tip. The tip of the catheter has no side-holes and an outer diameter of 1 mm.; its body has an outer diameter equivalent to that of a No. 7 French...

Nonspecificity of Abnormal Vascularity in the Angiographic Diagnosis of Malignant Neoplasms

The angiographic changes associated with malignant visceral neoplasms are described. Changes include abnormalities of proximal large arteries, neovasculature, regional blood flow alteration, and obstruction of draining veins. These changes, however, are not specific and may be seen in nonmalignant conditions. Pathological vessels may not respond to the intra-arterial injection of epinephrine. Abnormal hypervascularity is not an exclusive feature of malignant neoplasias and has been seen in angiodysplasias, hamartomas, and inflammatory conditions. Despite the nonspecificity of abnormal vascularity, angiography remains the most useful technique for establishing the presence and extent of malignant neoplasms.

Radiographic-pathologic correlation in the interpretation of lymphangioadenograms.

Lymphangioadenography is the radiologic study of lymph vessels and lymph nodes. This method of examination (a) contributes to the detection and evaluation of the extension of lymph-node metastases; (b) aids in the differential diagnosis of intra-abdominal and pelvic masses; (c) assists in the evaluation of surgical, chemotherapeutic, and radiation treatment of malignant disease; (d) provides information as to the cause of obstructive edema, especially when combined with phlebography; (e) aids in the diagnosis and therapeutic control of lymphoma; (f) facilitates pelvic and peri-aortic lymphadenectomy by staining the lymphatics when the opaque medium is mixed with a green dye (chlorophyll). Difficulties of technic and interpretation account for the failure of lymphangioadenography to gain popularity and wide acceptance. New advances in the field of technic, such as the use of FDC Blue #1 Dye6 for the identification of the lymph vessels, large-bore catheters, and an automatic pressure-temperature controlled ...

Proton Relaxation Times in Arterial Wall and Atheromatous Lesions in Man

The proton relaxation times of autopsy samples of arterial intima-media were measured with an NMR spectrometer and results correlated to the microscopically estimated lipid content of the vascular wall. The normal arterial intima-media contained two T1 relaxation components. The short T1 component (T1s) was 90 +/- 13 ms and its relative weight was 11%. The long T1 component (T1l) was 523 +/- 89 ms and relative weight 88%, respectively. The average T2 was 99 +/- 18 ms. In diseased vessels, a positive correlation was found between the lipid content of the vessel wall and the relaxation rate of the fast component. T1s of the intima-media was significantly shorter (P less than .01) in severe atheromatosis compared with vessels without fat deposition. The results suggest that atheromatous lesions should be best highlighted in spin-echo images by using short TR and TE to suppress the influence of T1l and to avoid (noncontrast contributing) T2 decay of the signal intensity.

Laparoscopic-assisted sigmoid colectomy and low anterior resection

Laparoscopic-assisted sigmoid colectomy or low anterior resection was undertaken in 30 selected patients. The median age was 51 (range, 30–85) years. Eight patients had previous abdominal surgery: four hysterectomies, two appendectomies, and two cholecystectomies. There was no mortality. Complications occurred in three patients. One patient developed a wound infection, there was one iliac artery injury, and one postoperative bleed, which did not require transfusion. Eighteen patients were operated on for primary cancer of the colon and 12 patients for benign disease. Technical aspects are described in detail. The average hospital stay was four days with most patients receiving oral analgesics by the second postoperative day. Laparoscopic colon resection can be an alternative to open surgery.