Biomedical subjects

E Fosse

Publications and source records attributed to E Fosse.

At least 19 recordsLinked to original sources

PubMed2006

Virtual reality simulator training equals mechanical robotic training in improving robot-assisted basic suturing skills.

BACKGROUND: This study aimed to investigate the effect of a virtual reality simulator on the learning of basic robotic suturing skills. METHODS: Two randomized groups of students underwent a controlled training program. Both groups completed an identical test before and after training. The increase in the number of stitches placed during the pretest and posttest was used as an objective measure of the training effect. To evaluate the subjective feeling of understanding and mastering, the students indicated this on a visual analog scale. RESULTS: Both groups showed a significant increase in the number of stitches placed during the posttest, and an increase in subjective feeling of understanding and mastering. The increase did not differ between the groups, indicating that the virtual reality simulator equaled the mechanical trainer in training of robotic suturing technique. CONCLUSIONS: Training in basic robot-assisted suturing skills using a virtual reality simulator without additional training equaled training using a mechanical simulator.

Computer Simulation↗

PubMed2006

Agreement between PiCCO pulse-contour analysis, pulmonal artery thermodilution and transthoracic thermodilution during off-pump coronary artery by-pass surgery.

BACKGROUND: Haemodynamic instability during off-pump coronary artery bypass surgery (OPCAB) may appear rapidly, and continuous monitoring of the cardiac index (CI) during the procedure is advisable. With the PiCCO monitor, CI can be measured continuously and almost real time with pulse-contour analysis and intermittently with transthoracic thermodilution. The agreement between pulmonal artery thermodilution CI (Tpa), transthoracic thermodilution CI (Tpc) and pulse-contour CI (PCCI) during OPCAB surgery has not been evaluated sufficiently. METHODS: In 30 patients scheduled for OPCAB surgery, a pulmonary artery catheter and a PiCCO catheter were inserted. At different time points during surgery, Tpa, Tpc and PCCI were compared. Measurements were performed after induction of anesthesia (T1), after pericardiothomy (T2), after grafting on the anterior (T3), posterior (T4) and lateral (T5) walls and after chest closure (T6). The PCCI was recalibrated at time point T2-T6. RESULTS: Mean difference and the limits of agreements (percentage error) between Tpa and Tpc were: -0.14 +/- 0.60 (22.0%) l/min/m2, between Tpa and PCCI: -0.07 +/- 0.92 (33.5%) l/min/m2 and between Tpc and PCCI: 0.10 +/- 1.00 (35.5%) l/min/m2. For changes in CI from one time point to the next (DeltaCI), the limits of agreements between DeltaCI Tpa and DeltaCI Tpc were 0.04 +/- 0.90 l/min/m2, between DeltaCI Tpa and DeltaCI PCCI: -0.02 +/- 1.22 l/min/m2 and between DeltaCI Tpc and DeltaCI PCCI: -0.08 +/- 1.32 l/min/m2. CONCLUSION: In OPCAB surgery, limits of agreement comparing thermodilution methods were smaller than comparing PCCI with thermodilution. Recalibration of PCCI is therefore advisable.

Adult↗

PubMed2006

Postoperative pain and convalescence in living kidney donors-laparoscopic versus open donor nephrectomy: a randomized study.

The aim of the present study was to compare postoperative pain and convalescence in patients randomized to laparoscopic or open donor surgery in a prospective, controlled trial. The donors were randomly assigned to undergo laparoscopic (n = 63) or open (n = 59) donor nephrectomy. Our end points were amount of administered analgesics in the recovery period, postoperative pain on the second postoperative day and at one month after surgery and duration of sick leave. There was a significant difference in favor of the laparoscopic group regarding administered analgesics on day of surgery (p < 0. 02). No difference was observed between groups regarding self-reported pain on the second postoperative day. One month post donation, significantly fewer donors in the laparoscopic group reported pain (p < 0. 02) or had used analgesics (p < 0.05). The duration of sick leave was significantly shorter in the laparoscopic group (p = 0.01). The laparoscopic group experienced a more rapid convalescence and a shorter period of sick leave. Although immediate postoperative pain can be managed efficiently regardless of procedure, a lower consumption of opioids and incidence of pain in the convalescent period suggest a clinically relevant patient-experienced benefit from a successful laparoscopic procedure.

Adult↗

PubMed2004

Laparoscopic resection of the pancreas: a feasibility study of the short-term outcome.

BACKGROUND: Laparoscopic resection is not an established treatment for tumors of the pancreas. We report our preliminary experience with this innovative approach to pancreatic disease. METHODS: Thirty two patients with pancreatic disease were included in the study on an intention-to-treat basis. The preoperative indications for surgery were as follows: neuroendocrine tumors ( n=13), unspecified tumors ( n=11), cysts ( n=2), idiopathic thrombocytopenic purpura with ectopic spleen ( n=2), annular pancreas ( n=1), trauma ( n=1), aneurysm of the splenic artery ( n=1), and adenocarcinoma ( n=1). RESULTS: Enucleations ( n=7) and distal pancreatectomy with ( n=12) and without splenectomy ( n=5) were performed. Three patients underwent laparoscopic exploration only. Four procedures (13%) were converted to an open technique. One resection was converted to a hand-assisted procedure. The mortality rate for patients undergoing laparoscopic resection was 8.3% (two of 24). Complications occurred after resection in nine of 24 procedures (38%). The median hospital stay was 5.5 days (range, 2-22). Postoperatively, opioid medication was given for a median of 2 days (range, 0-13). CONCLUSION: Resection of the pancreas can be performed safely via the laparoscopic approach with all the potential benefits to the patients of minimally invasive surgery.

Adenocarcinoma↗

PubMed2004

Cryoablation of colorectal liver metastases: minimally invasive tumour control.

BACKGROUND: Freezing is used for in situ destruction (ablation) of liver tumours not eligible for resection. The procedure is typically done during laparotomy. The objective of this report was to study tumour control at the site of freezing and a minimally invasive approach to cryoablation of colorectal liver metastases. METHODS: A prospective study of 19 patients was conducted between 1999 and 2003. Twenty-five tumours were ablated during 24 procedures (i.e. 5 reablations). Sixteen procedures were performed percutaneously, 5 during laparotomy and 3 laparoscopically. Magnetic resonance imaging (MRI) was used for intraprocedural monitoring during most procedures. Nine patients had concomitant liver resections performed (5 during laparoscopy, 4 during laparotomy). RESULTS: Out of 25 ablations, 18 (72%) were assumed adequate. Total ice-ball volume during percutaneous procedures was median 62 cm (range 32-114). Excellent imaging of the extent of freezing was achieved using MRI. Hospital stay for patients treated percutaneously was median 4 days (range 3-30). No perioperative mortality occurred. Tumour recurrence at the site of ablation occurred in 8 of 18 (44%) tumours adequately ablated. Actuarial 2-year tumour-free survival at site of ablation was 48%. At the time of analyses 12 out of 13 (92%) patients assumed to be adequately ablated were alive. Of all patients, 14 out of 19 (74%) survived. CONCLUSIONS: Short-term tumour control can be achieved following cryoablation of colorectal liver metastases. A minimally invasive approach is feasible but the diameter of metastases considered for percutaneous cryoablation should not exceed 3 cm.

Aged↗

PubMed2002

A comparative study of the short-term outcome following open and laparoscopic liver resection of colorectal metastases.

BACKGROUND: Laparoscopic resection of liver tumors is feasible, but few studies have compared short-term outcome of the laparoscopic approach to that of a conventional technique. METHODS: Eighteen tumor resections performed during 14 procedures (14 patients) by conventional surgery were compared to 21 similar resections performed laparoscopically during 15 procedures (13 patients). All patients had colorectal liver metastases. RESULTS: No perioperative mortality occurred. Surgical time, peroperative bleeding and blood transfusion requirement were similar in the two groups. The resection margin was involved by tumor tissue in one specimen laparoscopically resected and in two specimens conventionally resected (p = 0.58). Patients operated laparoscopically remained in hospital for median 4 days, while patients operated conventionally stayed median 8.5 days (p <0.001). Patients operated laparoscopically required less opioid medication than patients having conventional surgery (median 1 vs 5 days; p = 0.001). CONCLUSIONS: Short-term outcome of laparoscopic liver resection compares to that of conventional surgery, with the additional benefits derived from minimal invasive therapy.

Adult↗

PubMed2001

[Cryoablation--a treatment option for inoperable liver tumors?].

BACKGROUND: Most patients with primary and secondary liver tumours are inoperable by conventional surgery. This has prompted the development of different techniques of local destruction of liver tumours, i.e. cryosurgical ablation radiofrequency, laser, and microwave ablation. MATERIAL AND METHODS: On the basis of relevant literature and our own experience we describe the principles of local destruction by cryoablation of colorectal metastases. RESULTS: Indications for ablation are mainly colorectal metastases and hepatocellular carcinoma. Mechanisms for tumour destruction include intra- and extracellular ice crystal formation, cellular membrane rupture, cellular dehydration and ischaemic damage. Ablation is regularly monitored by ultrasonography, which is suboptimal because of inadequate visualisation of the iceball. Long-term outcome of local destruction of liver tumours is not documented and randomized trials are not ethically acceptable. This complicates analyses of patient outcomes. INTERPRETATION: Local ablation of liver tumours is experimental therapy and should only be performed as a part of prospective trials.

Carcinoma, Hepatocellular↗

PubMed2001

Laparoscopic and open surgery for pheochromocytoma.

BACKGROUND: Laparoscopic adrenalectomy is a promising alternative to open surgery although concerns exist in regard to laparoscopic treatment of pheocromocytoma. This report compares the outcome of laparoscopic and conventional (open) resection for pheocromocytoma particular in regard to intraoperative hemodynamic stability and postoperative patient comfort. METHODS: Seven patients laparoscopically treated (1997-2000) and nine patients treated by open resection (1990-1996) at the National Hospital (Rikshospitalet), Oslo. Peroperative hemodynamic stability including need of vasoactive drugs was studied. Postoperative analgesic medication, complications and hospital stay were recorded. RESULTS: No laparoscopic resections were converted to open procedure. Patients laparoscopically treated had fewer hypertensive episodes (median 1 vs. 2) and less need of vasoactive drugs peroperatively than patients conventionally operated. There was no difference in operative time between the two groups (median 110 min vs. 125 min for adrenal pheochromocytoma and 235 vs. 210 min for paraganglioma). Postoperative need of analgesic medication (1 vs. 9 patients) and hospital stay (median 3 vs. 6 days) were significantly reduced in patients laparoscopically operated compared to patients treated by the open technique. CONCLUSION: Surgery for pheochromocytoma can be performed laparoscopically with a safety comparable to open resection. However, improved hemodynamic stability peroperatively and less need of postoperative analgesics favour the laparoscopic approach. In experienced hands the laparoscopic technique is concluded to be the method of choice also for pheocromocytoma.

Adrenal Gland Neoplasms↗

PubMed2001

[Skin biopsy for quantification of intraepidermal nerve fibers].

BACKGROUND: Skin biopsy for quantification of intraepidermal nerve fibre density has recently been introduced as a method for diagnosis of peripheral neuropathies. Immunostaining by antibody to protein gene product 9.5 has proved particularly useful because it selectively visualizes the epidermal nerve fibres. MATERIAL AND METHODS: We describe the procedure on the basis of relevant literature and our own experience. Results from investigations of 56 healthy individuals and three patients with small fibre involvement as part of their neuropathy are presented. RESULTS: In the healthy individuals, the mean density of epidermal fibres was 12.4 (SD 4.6), median 11.3 and range 6.0-26.1. Three patients with small fibre neuropathy had low intraepidermal nerve fibre density. INTERPRETATION: Skin biopsy for determination of intraepidermal nerve fibre density is a simple and non-painful procedure. Skin biopsies can be done repeatedly and may be used for the purpose of monitoring potential therapeutic agents.

Age Factors↗

PubMed2001

Validation of estimated 3D temperature maps during hepatic cryo surgery.

A simple model for estimating temperature distribution within the frozen region during cryo ablation was tested for accuracy. Freezing experiments were conducted in both ex vivo and in vivo porcine livers. Temperature was measured during freezing using a fiber-optic temperature sensor. Three-dimensional MR images were obtained at the end of each freezing cycle. From the MR image volumes, three-dimensional temperature maps were calculated numerically using a simplified bio-heat model. Estimated temperatures were compared to measured temperatures. The median difference between measured and estimated temperature was 3.03 degrees C. The median distance from a sensor element to the closest point on a isotherm surface with the corresponding estimated temperature was 0.70 mm. The accuracy of this model is acceptable. Temperature maps as outlined here may be used for monitoring of cryotherapy in order to increase clinical effectiveness.

Animals↗

PubMed2001

Magnetic-resonance-guided percutaneous cryoablation of hepatic tumours.

OBJECTIVE: To study the feasibility of percutaneous cryoablation of hepatic tumours monitored by magnetic resonance imaging (MRI). DESIGN: Prospective study SETTING: University hospital, Norway PATIENTS: Six patients with hepatic metastases from colorectal cancer. INTERVENTIONS: Percutaneous cryoprobe positioning under general anaesthesia. Positioning and freezing monitored by near-real-time MRI using an open 0.5 Tesla MRI configuration system. MAIN OUTCOME MEASURES: Safety and feasibility of the procedure. Measurement of volumes of cryolesions. RESULTS: One patient developed a biliary leakage that had to be drained. Four patients developed pleural fluid. Two small tumours were adequately cryoablated. In the remaining 4 patients with large (>4 cm) tumours, an adequate cryolesion could not be formed. Cryolesion volumes larger than 105 cm3 were not produced even using 3-4 probes. MRI visualised the growing cryolesion well, but positioning of the cryoprobes was time-consuming. CONCLUSION: MR guided cryoablation is clinically feasible and gives good visualisation of the procedure. Patients with small tumours (<3 cm) seem to be best suited to this percutaneous approach as cryolesion volumes claimed to be adequate for tumour destruction can be produced. Measurement of tumour volume preoperatively may help to select patients who will respond.

Aged↗

PubMed2001

Liver tumors and minimally invasive surgery: a feasibility study.

Laparoscopic liver resection has not yet been established, although recent reports document that liver resection can be performed safely by the laparoscopic approach. Other interventional procedures like cryoablation have also been introduced in treatment of liver metastases. In this report 11 liver resections performed laparoscopically in eight patients are presented. Six patients had colorectal metastases, one a metastases from a malignant melanoma, and one patient had focal nodular hyperplasia. Two patients received synchronous cryoablation of remaining liver metastases. During follow up, two patients received percutaneous cryoablation of liver recurrences monitored by an open configuration magnetic resonance scanner. All except one of the tumors we attempted to remove had free resection margins (re-resection of new metastasis). No complications occurred except an atelectasis of the left lower pulmonary lobe in one patient. Median postoperative hospital stay was 3 days, and median postoperative opioid-dependent days was 1. The report demonstrates that minimally invasive techniques may safely be combined in hepatic intervention, and that the advantages of minimally invasive surgery, such as reduced hospital stay and less patient discomfort, also applies to liver resections.

Adenocarcinoma↗

PubMed2001

Ventricular fibrillation during off-pump coronary artery bypass grafting: transcranial Doppler and clinical findings.

A 73-year-old male developed ventricular fibrillation which lasted for 2 min and 24 s, during off-pump coronary artery bypass grafting. Cerebral hemodynamics were assessed by continuous transcranial Doppler monitoring. Ventricular fibrillation resulted in an immediate fall in cerebral blood flow velocities to almost zero with only slight fluctuations. This was then followed by a pronounced reactive hyperperfusion. Cerebral magnetic resonance imaging examinations and detailed neurological and neuropsychological evaluations were performed before and at 3 and 12 months after surgery. No evidence of cerebral damage was found.

Aged↗

PubMed2001

Digital trainer developed for robotic assisted cardiac surgery.

Robotic systems for cardiac surgery have been introduced in clinical trials to facilitate minimally invasive techniques. Widespread use of surgical robotics necessitates new training methods to improve skills and continue practicing as the robotic systems are frequently being upgraded. Today, robotic training is performed on expensive animal models. An integration of a digital trainer with the two present robotic systems applied in coronary artery bypass procedures on beating heart requires real time simulation of tissue mechanics, sutures, instruments and bleeding. However, it requires no extra haptic device, since the robotic master is the haptic apparatus itself. By developing new data structures and parametric geometry descriptions we have demonstrated the possibility of obtaining surgical simulation on a standard PC Linux system. This technology is beneficial when simulation is exploited over a network with limited bandwidth, especially when it comes to the handling of soft tissue dynamics.

Computer Simulation↗

PubMed2001

Graft control by transit time flow measurement and intraoperative angiography in coronary artery bypass surgery.

BACKGROUND: The aim of this study was to compare the relationship between intraoperative transit time flow measurements and angiographic findings with long-term graft patency in 72 patients who underwent coronary artery bypass surgery. METHODS: Transit time flow measurements with recording of mean flow and pulsatility indexes were performed after completion of the anastomoses. Coronary angiography was performed on-table while the patients were still in general anesthesia, and then at follow-up three months and 12 months after surgery. Based on angiography, the grafts were graded as type A (fully patent), type B (having more than 50% diameter reduction), or type O (occluded). RESULTS: Of the 67 left internal mammary artery (LIMA) grafts, 51 (76%) were type A on-table, 14 (21%) were type B, and two (3%) were type O. Of the 57 saphenous vein grafts, 49 (86%) were type A, 7 (12%) were type B, and one (2%) was type O. For both LIMA and vein grafts, there were no differences in flow (p = 0.69 and 0.47, respectively) or pulsatility index (p = 0.79 and 0.83) between type A and B. There were also no differences in flow (p = 0.37 and 0.7) or pulsatility index (p = 0.37 and 0.24) between type B on-table that either normalized or persisted occluded at the follow-up. Transit time flow measurement failed to detect an occluded LIMA graft as shown by intraoperative angiography. CONCLUSIONS: Blood flow measurements performed intraoperatively could not identify significant lesions in arterial or vein grafts, and could not predict graft patency. We have become cautious in interpreting flow measurements alone and combine blood flow recordings with intraoperative angiography in the assessment of graft quality.

Aged↗

PubMed2000

[Image guided and robotic treatment--the advance of cybernetics in clinical medicine].

The introduction of advanced technology in hospitals has changed the treatment practice towards more image guided and minimal invasive procedures. Modern computer and communication technology opens up for robot aided and pre-programmed intervention. Several robotic systems are in clinical use today both in microsurgery and in major cardiac and orthopedic operations. As this trend develops, professions which are new in this context such as physicists, mathematicians and cybernetic engineers will be increasingly important in the treatment of patients.

Cybernetics↗

PubMed2000

Functional imaging of the thoracic outlet syndrome in an open MR scanner.

Symptoms due to thoracic outlet syndrome may present only in abduction, a position that cannot be investigated in conventional MR scanners. Therefore, this study was initiated to test MRI in an open magnet as a method for diagnosis of thoracic outlet syndrome. Ten volunteers and 7 patients with a clinical suspicion of thoracic outlet syndrome were investigated at 0.5 T in an open MR scanner. Sagittal 3D SPGR acquisitions were made in 0 and 90 degrees abduction. In the patients, a similar data set was also obtained in maximal abduction. To assess compression, the minimum distance between the first rib and the clavicle, measured in a sagittal plane, was determined. In the neutral position, no significant difference was found between patients and controls. In 90 degrees abduction, the patients had significantly smaller distance between rib and clavicle than the controls (14 vs 29 mm; p < 0.01). On coronal reformatted images, the compression of the brachial plexus could often be visualised in abduction. Functional MR examination seems to be a useful diagnostic tool in thoracic outlet syndrome. Examination in abduction, which is feasible in an open scanner, is essential for the diagnosis.

Adult↗

PubMed2000

Intraaortic balloon pumping for predominantly right ventricular failure after heart transplantation.

BACKGROUND: Right ventricular failure from elevated pulmonary vascular resistance in the recipient is a main cause of early mortality after heart transplantation. When pharmacologic treatment is insufficient, mechanical circulatory assistance has been used to support the failing right ventricle. Considering right and left ventricular interdependence, we investigated whether intraaortic balloon counterpulsation (IABP) might also alleviate predominantly right ventricular dysfunction after heart transplantation. METHODS: Among 278 cardiac recipients, 12 adult patients underwent mechanical circulatory support for cardiac allograft dysfunction. Five patients were treated with percutaneous IABP for early postoperative low cardiac output syndrome characterized by predominantly right ventricular failure. Clinical data and hemodynamic variables were recorded before and during IABP treatment. RESULTS: Cardiac index (CI) and mean arterial pressure (MAP) increased (CI 1.7 +/- 0.1 to 2.5 +/- 0.2, MAP 53 +/- 12 to 71 +/- 7, p < 0.05) within 1 hour after IABP, whereas central venous pressure (CVP) and pulmonary artery wedge pressure (PAWP) decreased (CVP 21.6 +/- 1.7 to 13.8 +/- 3.1, p < .05; PAWP 14.8 +/- 4.9 to 12.4 +/- 3.7, nonsignificant). Within the next 12 hours, CI and mixed venous oxygen saturation increased (p < 0.05) and pulmonary artery pressure decreased (p < 0.05). All 5 patients were weaned successfully and 4 are long-term survivors with adequate cardiac performance at 1 year follow-up. CONCLUSIONS: Intraaortic balloon pumping is a minimally invasive circulatory assist device with proved efficiency in low cardiac output syndromes. This report shows that low output syndrome caused by predominantly right ventricular allograft failure may be an additional indication for IABP.

Adult↗