Operators believe patient-specific rehearsal improve individual and team performance.

INTRODUCTION: Rehearsing endovascular aortic aneurysm repair on patient-specific data is recent within virtual reality simulation and opens up new possibilities for operators to prepare for complex procedures. This study evaluated the feasibility of patient-specific rehearsal (PsR) and assessed operators' appraisal of the VIST-LAB simulator from Mentice. MATERIAL AND METHODS: CT-data was segmented and uploaded to the simulator, and simulated for 30 elective EVAR patients. Operators were asked how they perceived the PsR on a Likert scale after the PsR (once) and after the following procedure (each time). RESULTS: Patients were simulated and operated by 14 operators, always in pairs of one vascular surgeon and one interventional radiologist. The operators estimated that PsR improved individual and team performance (median 4), and recommended the use of PsR in general (median 4) and for difficult cases (median 5). The simulator realism got moderate scores (median 2-3). Inexperienced operators seemed to appreciate the PsR the most. CONCLUSIONS: PsR was feasible and was evaluated by operators to improve individual and team performance. Inexperienced users were more positive towards PsR than experienced users. PsR realism and the ease of importing patient-specific data can still be improved, and further studies to quantify and precisely identify benefits are needed.

[Recurrence and survival after surgical treatment of lung cancer]. / Residiv og overlevelse etter kirurgisk behandling for lungekreft.

BACKGROUND: 2500 new cases of lung cancer are diagnosed in Norway annually. Patients with limited disease can be operated, but many will die from the disease despite surgical treatment. The aim of the study was to review survival and recurrence, and factors which affect survival, in patients operated for lung cancer. MATERIAL AND METHODS: The risk of death and recurrence of disease was assessed retrospectively in patients who had non-small lung cancer and were operated at St. Olavs University Hospital, Trondheim in the period 1994-2001. Patient data were retrieved from medical records and a database with records from thoracosurgical procedures. RESULTS: 190 patients (30 % women) were included in the study. Average observation time after surgery was 58.3 months (range 21-99). Adenocarcinoma was the most common histological cancer type and occurred in 57.9 % of women and 39.1 % of the men (p = 0.02). The 30-day mortality rate was 3.2 % and the 60-day rate was 4.7 %. Recurrence of the disease was found in 45.8 %, among them median time to recurrence was 9 months after the operation. 5-year survival was 42 %, as analysed by the Kaplan-Meier estimate, and survival was best for early stages of the disease. 5-year survival was better for women (53.3 %) than men (36.8 %), p = 0.05. Prognostic factors for survival, estimated by Hazard ratio for death with Cox multiple regression analysis, were sex, age at the time of operation, type of operation, tumour diameter and postoperative N-stage. INTERPRETATION: Postoperative mortality and survival corresponded to data in the literature. Early stage lung cancer can be cured with surgical treatment. Our study confirms an increase in the incidence of adenocarcinoma among lung cancer patients during the last decades. Female sex is a positive prognostic factor for survival, as is young age, small tumor size, standard lobectomy, and absence of lymph node metastases.

Initial observations of endovascular aneurysm repair using Dyna-CT.

PURPOSE: To examine the feasibility of a new technology that provides images resembling computed tomographic (CT) slices on the operating table during elective endovascular abdominal aortic aneurysm (AAA) repair (EVAR). TECHNIQUE: Commercially available Dyna-CT equipment was used in conjunction with Voxar 3D software for image reconstruction. During the preliminary evaluation of 9 patients (7 men; median age 73 years, range 67-84) with non-ruptured AAA undergoing elective EVAR with the Zenith Trifab stent-graft under regional anesthesia, the equipment functioned sufficiently well to produce the planned image dataset in 8 of 9 patients. Rotation failed in 1 overweight individual due to a short distance between the patient's abdomen and the C-arm. In 7 of 8 patients, the radiologist was able to measure the diameter of the aneurysm, and it was possible to visualize the entire length of the treated aorta and the iliac arteries in all cases. The proximal aortic neck, including the stent-graft, was visualized in 7 cases. No endoleak or other complications was detected, which was confirmed on the pre-discharge CT scans. The time interval from the rotation of the C-arm until the appearance on the monitor of the first automatically generated 3D images was 7 minutes, which has subsequently been reduced to approximately 2 minutes. CONCLUSION: Our preliminary experience with Dyna-CT is promising, but further research is necessary to define the place of this imaging modality in EVAR.

Strain estimation in abdominal aortic aneurysms from 2-D ultrasound.

The rupture risk of abdominal aortic aneurysms (AAAs) is routinely inferred from the maximum diameter of the AAA. However, clinical experience indicates that this criterion has poor accuracy and that noninvasive assessment of the elastic properties of the vessel might give better correspondence with the rupture risk. We have developed a method for analysis of circumferential strain in AAAs from sequences of cross-sectional ultrasound B-mode images. The algorithm is fast, semiautomatic and well-suited for real-time applications. The method was developed and evaluated using data from 10 AAA patients. The preliminary results demonstrate that the method is sufficiently accurate and robust for clinically acquired data. An important finding is that local strain values may exceed the circumferential average strain significantly. Furthermore, the calculated strain shows no apparent covariation with the diagnosed diameter. This implies that the method may give new and essential information on the clinical condition of the AAA.

Three-dimensional teleradiology for surveillance following endovascular aortic aneurysm repair: a feasibility study.

PURPOSE: To study the feasibility of 3-dimensional (3D) teleradiology in surveillance of patients treated with stent-grafts for abdominal aortic aneurysm (AAA). METHODS: Between April 2002 and November 2003, 8 AAA patients (7 men; median age 73 years, range 62-84) with stent-grafts had follow-up computed tomograms (CT) performed at their local hospital and transmitted without loss across a broadband connection to the university hospital. On both monitors, the radiologists were presented with the complete CT axial dataset, sagittal and coronal reformatted slices, and a 3D volume-rendered reconstruction. The two radiologists were then able to simultaneously perform measurements and real-time manipulations of the axial and 3D pictures, which were discussed over the telephone or using a videoconferencing unit. Patient satisfaction, the radiologists' evaluation of the method, and the potential cost savings were explored. RESULTS: Twelve follow-up CT scans were performed on the 8 patients. The time for transmission over the teleradiological network averaged 5 minutes, and the evaluation required 15 minutes at the university hospital. The overall technical quality of the images was rated as good by the university radiologist. In 11 studies, the stent-grafts were satisfactory, but a type III endoleak was detected in one 5.5-year-old stent-graft. Neither radiologist had a problem identifying the endoleak. Patients had confidence that the examination at the local hospital was of good quality; they all felt that they received good care and were pleased with avoiding travel to the university hospital. From the economic analysis, an annual savings of 40,000 Euros (USD 52,304) was projected, mostly due to avoiding hospital stays and outpatient consultations at the university hospital. CONCLUSIONS: The experiences from this study are encouraging, but a larger series will be necessary for a thorough evaluation of 3D teleradiology as a surveillance method for aortic stent-graft patients.

[Nine years' experience with endovascular treatment of abdominal aortic aneurysms]. / Ni års erfaring med endovaskulaer behandling av abdominale aortaaneurismer.

BACKGROUND: Endovascular repair of abdominal aortic aneurysm was started nine years ago at our institution. Our purpose was to evaluate the results over this period. MATERIAL AND METHODS: From 1995 to 2003, a total of 148 patients were treated for infrarenal abdominal aortic aneurysms by endovascular repair. The material includes 31 patients (21%) who were unfit for open surgery because of comorbidity or poor general condition. The patients have been followed up at regular intervals with clinical investigation, plain abdominal X-ray, and CT scans. Regional anaesthesia was used for 143 procedures; 5 were carried out under general anaesthesia. RESULTS: 30-day mortality following elective procedures was 2.3%. 31 endo-leaks were observed, 16 early and 15 late. Furthermore, 22 graft limb occlusions were diagnosed and thirteen of them repaired with femoro-femoral bypass. Secondary procedures were necessary in 42 (28.4%) of the patients, including 7 late conversions to open surgery. Some patients had more than one secondary procedure. With better stent grafts, the incidence of complications and secondary procedures has decreased significantly. During the last 4.5 years, only 4 secondary procedures (5.8%) have been necessary in 69 patients. In the total material the accumulated five-year survival rate was about 60%. INTERPRETATION: Results from endovascular repair of abdominal aortic aneurysm have improved in recent years. Ongoing prospective randomised studies could give us the information we need in order to establish what role this treatment should have.

Combined open and endovascular treatment of complex aortic disease.

The purpose of this article is to report whether combined open and endovascular treatment could be applied in patients with complex aortic disease. A retrospective study including four patients with complex aortic disease was undertaken. In all patients, extra-anatomic bypass to the visceral arteries was made through a laparotomy while the aortic lesion was repaired by stent grafting. One patient died on the first postoperative day and another died 3 months after treatment from a myocardial infarction. The other two patients were alive 13 and 34 months after treatment, respectively. However, a patient treated for a ruptured thoracoabdominal type 2 aneurysm on the basis of a dissection suffers from postoperative paraplegia. The combination of open surgery with extra-anatomic bypass to visceral arteries and stent grafting could be an option for the treatment of patients with complex aortic disease, especially in high-risk cases in which more extensive open surgery is contraindicated.

Iohexol-induced neutrophil myeloperoxidase release and activation upon contact with vascular stent-graft material: a mechanism contributing to the postimplantation syndrome?

PURPOSE: To investigate whether the contrast medium iohexol alone or in combination with vascular stent-graft material induces neutrophil degranulation. METHODS: Human whole blood or isolated human neutrophils were incubated with or without iohexol and vascular stent-graft material. Samples were also drawn from 5 patients undergoing diagnostic angiography using iohexol. Myeloperoxidase and lactoferrin concentrations were determined by enzyme immunoassays. RESULTS: Both in vitro and in the patients, iohexol induced neutrophil degranulation with considerable individual variation in dose sensitivity and timing. The in vitro effect was independent of the type of anticoagulant used (ethylenediamine tetra-acetic acid, heparin, lepirudin). Experiments using isolated neutrophils showed that degranulation was independent of complement activation or platelet-derived mediators. The dose for maximal response varied from 5 to 50 mg I/mL (10.7-107.6 mg/mL iohexol). In vitro, vascular stent-graft material alone did not induce neutrophil degranulation. As compared to iohexol alone, incubation with iohexol and vascular stent-graft material in combination substantially increased the release of myeloperoxidase. CONCLUSIONS: Iohexol induces neutrophil degranulation, which is greatly enhanced when combined with vascular stent-graft material. Thus, iohexol-induced neutrophil activation may contribute to an inflammatory response following stent-graft implantation. We speculate that neutrophil activation during other procedures combining catheters and iohexol (e.g., angiography) may induce inflammation, which might have detrimental effects.

Type III endoleak from a thoracic aortic stent-graft.

PURPOSE: To present an as yet unreported late complication of an Excluder thoracic endograft. CASE REPORT: A 78-year-old man underwent surgery for a ruptured type V thoracoabdominal aortic aneurysm in 1996. Four years later, an aneurysm was detected in the proximal thoracic aorta and repaired with 2 Excluder endoprostheses. At 12 months, computed tomography showed an increase in the aneurysm sac diameter and a type III endoleak, which was traced to a hole in the stent-graft fabric on arteriography. No fracture of the metal components was detected in the stent-grafts. Another Excluder device was implanted within the distal endograft. Satisfactory exclusion of the leak has been maintained for 6 months. CONCLUSIONS: The risk of type III leaks must be minimized before stent-grafting can be regarded as a routine procedure in the treatment of thoracic aortic aneurysms.