Development and validation of a curriculum for laparoscopic supracervical hysterectomy.

STUDY OBJECTIVE: To develop and validate a three-step curriculum for laparoscopic supracervical hysterectomy (LSH) designed for a busy clinical setting. NETHODS: Single-centre, prospective, cohort study. Twelve eligible gynaecological trainees were included (group 1). The theoretical part (step 1) was a validated multiple-choice test. The practical part (step 2) consisted of five tasks on a virtual reality simulator. The participants had to reach a pre-defined proficiency level before advancing to performing a LSH (step 3). The validation of the curriculum was based on the surgical performance. The surgical procedure was recorded and assessed by two experts using Global Operative Assessment of Laparoscopic Skills (GOALS) and Competence Assessment Tool - Laparoscopic Supracervical Hysterectomy (CAT-LSH). The scores were compared with scores from gynaecological trainees who performed their first LSH without virtual reality simulator training (group 2). RESULTS: Ten trainees completed the curriculum and performed a LSH that was recorded and evaluated. Mean duration of the training period (step 1 and 2) was 57 days (SD 26.0), and mean training time spent on the simulator to reach the pre-set proficiency level was 173 min (SD 49). The mean GOALS score was 18.5 (SD 5.8) in group 1 and 13.6 (SD 3.3) in group 2, p=0.027. The mean CAT-LSH score of the performance of the hysterectomy was 42.1 (SD 6.9) in group 1 and 34.8 (SD 4.3) in group 2, p= 0.009. CONCLUSIONS: Trainees who completed the curriculum appeared to have a higher performance score compared with trainees who did not perform structured training.

Development and validation of a general and easy assessable scoring system for laparoscopic skills using a virtual reality simulator.

OBJECTIVES: To develop and validate a scoring system for laparoscopic skills for five specific tasks on a virtual reality simulator. STUDY DESIGN: A longitudinal, experimental, non-randomised study including 30 gynecologists and gynecological trainees at three hospitals. The participants were categorized as inexperienced (Group 1), moderately experienced (Group 2), and experienced (Group 3).The study participants performed ten repetitions of three basic skill tasks, a salpingectomy and a laparoscopic supracervical hysterectomy on a virtual reality simulator. Assessment of skills was based on time, error parameters and economy of movements measured by the simulator. We used the results (mean and SD for each parameter in all tasks) of the four last repetitions performed by the experienced gynecologists as the basic for the scoring system. Performance equal to, and higher than, this mean score gave 2 points. A decrease of 1 SD from the mean gave 1 point. Every score below gave 0 points. The mean score for the inexperienced, moderately experienced and experienced study participants was compared. RESULTS: The mean scores in Task 1 were 3.4 (SD 0.6) in Group 1, 3.4 (SD 0.6) in Group 2 and 5.1 (SD 1.1) in Group 3, respectively. There was a statistically significant difference in score between Group 1 and 3 (p = 0.01), and group 2 and 3 (p = 0.01). In Task 2 no statistical significant differences were found. In Task 3, the total mean scores were 1.7 (SD 0.7) in Group 1, 1.9 (SD 0.9) in Group 2 and 2.8 (SD 0.5) in Group 3, respectively. The difference in score between study groups was statistically significant when comparing Group 1 and Group 3 (p < 0.01) and Group 2 and Group 3 (p = 0.02).In Task 4, the difference in used time between group 1 and 3 was statistically significant (p = 0.03). In task 5 there was a significant difference in performance score between group 1 and 3 (p = 0.01). CONCLUSIONS: There was significant difference in scores between the experienced and the inexperienced gynecologist in four out of five tasks.The scoring system is easy assessable and can be used for summative and formative feedback in proficiency-based assessment.

Addressing the social determinants of health at the local level: Opportunities and challenges.

AIMS: The gradient in health inequalities reflects a relationship between health and social circumstance, demonstrating that health worsens as you move down the socio-economic scale. For more than a decade, the Norwegian National government has developed policies to reduce social inequalities in health by levelling the social gradient. The adoption of the Public Health Act in 2012 was a further movement towards a comprehensive policy. The main aim of the act is to reduce social health inequalities by adopting a Health in All Policies approach. The municipalities are regarded key in the implementation of the act. The SODEMIFA project aimed to study the development of the new public health policy, with a particular emphasis on its implementation in municipalities. METHODS: In the SODEMIFA project, a mixed-methods approach was applied, and the data consisted of surveys as well as qualitative interviews. The informants were policymakers at the national and local level. RESULTS: Our findings indicate that the municipalities had a rather vague understanding of the concept of health inequalities, and even more so, the concept of the social gradient in health. The most common understanding was that policy to reduce social inequalities concerned disadvantaged groups. Accordingly, policies and measures would be directed at these groups, rather than addressing the social gradient. CONCLUSIONS: A movement towards an increased understanding and adoption of the new, comprehensive public health policy was observed. However, to continue this process, both local and national levels must stay committed to the principles of the act.

Trends in Abdominal Aortic and Iliac Aneurysm Repairs in Norway from 2001 to 2013.

OBJECTIVE/BACKGROUND: The objective was to examine trends in abdominal aortic and iliac aneurysm repairs in Norway from 2001 to 2013, and study regional variations and organizational developments in this type of vascular surgery. METHODS: This was a retrospective study on aortic and iliac aneurysm repairs using data from the Norwegian Patient Register. The vascular centers were categorized by yearly volume of repairs into small (<18), medium (18-49) and large (≥50). Incidence rates were assessed per 100,000 ≥ 60 years. The percentage of endovascular aneurysm repairs (EVAR) was calculated among the conducted repairs at the three categories of centers and the South-Eastern, Western, Central, and Northern Norway Regional Health Authority (NRHA). RESULTS: The national incidence rates of intact repairs per 100,000 ≥ 60 years increased from 57.4 to 65.7 (p < .01). Ruptured repairs decreased from 19.7 to 9.2 (p < .01). The rate of EVAR increased from 6.0 to 29.9 (p < .01) in intact and from 0.4 to 2.5 (p < .01) in ruptured repairs. The vascular centers were reduced from 25 to 16. The rate of EVAR was 27.1% (p < .01) higher at large centers and 7.9% (p < .03) higher at medium centers compared with small centers, and from 11.1% to 15.7% higher (p < .01) at the Central, Western, and Northern NRHA compared with the South-Eastern NRHA, which had the most centers (also in the large category). The national increase in intact EVAR from 10.6% to 43.3% was less compared with many other Western countries. CONCLUSION: During the study period the rates of intact repairs increased while the ruptured repairs decreased. EVAR was associated with centers performing high volumes of abdominal aortic and iliac aneurysm repairs and regional authorities organized with few centers.

Myocardial tissue CO2 tension detects coronary blood flow reduction after coronary artery bypass in real-time†.

BACKGROUND: Coronary stenosis after coronary artery bypass grafting (CABG) may lead to myocardial ischaemia and is clinically difficult to diagnose. In a CABG model, we aimed at defining variables that detect hypoperfusion in real-time and correlate with impaired regional ventricular function by monitoring myocardial tissue metabolism. METHODS: Off-pump CABG was performed in 10 pigs. Graft blood flow was reduced in 18 min intervals to 75, 50, and 25% of baseline flow with reperfusion between each flow reduction. Myocardial tissue Pco2 (Pt(CO2)), Po2, pH, glucose, lactate, and glycerol from the graft supplied region and a control region were obtained. Regional cardiac function was assessed as radial strain. RESULTS: In comparison with baseline, myocardial pH decreased during 75, 50, and 25% flow reduction (-0.15; -0.22; -0.37, respectively, all P<0.05) whereas Pt(CO2) increased (+4.6 kPa; +7.8 kPa; +12.9 kPa, respectively, all P<0.05). pH and Pt(CO2) returned to baseline upon reperfusion. Lactate and glycerol increased flow-dependently, while glucose decreased. Regional ventricular contractile function declined significantly. All measured variables remained normal in the control region. Pt(CO2) correlated strongly with tissue lactate, pH, and contractile function (R=0.86, R=-0.91, R=-0.70, respectively, all P<0.001). New conductometric Pt(CO2) sensors were in agreement with established fibre-optic probes. Cardiac output was not altered. CONCLUSIONS: Myocardial pH and Pt(CO2) monitoring can quantify the degree of regional tissue hypoperfusion in real-time and correlated well with cellular metabolism and contractile function, whereas cardiac output did not. New robust conductometric Pt(CO2) sensors have the potential to serve as a clinical cardiac monitoring tool during surgery and postoperatively.

Detection of myocardial ischaemia by epicardial accelerometers in the pig.

BACKGROUND: We describe a novel technique for continuous real-time assessment of myocardial ischaemia using a three-axis accelerometer. METHODS: In 14 anaesthetized open-chest pigs, two accelerometers were sutured on the left ventricle (LV) surface in the perfusion areas of the left anterior descending (LAD) and circumflex (CX) arteries. Acceleration was measured in the longitudinal, circumferential, and radial directions, and the corresponding epicardial velocities were calculated. Regional LV dysfunction was induced by LAD occlusion for 60 s. Global LV function was altered by nitroprusside, epinephrine, esmolol, and fluid loading. Epicardial velocities were compared with strain by echocardiography during LAD occlusion and with aortic flow and LV dP/dt(max) during interventions on global LV function. RESULTS: LAD occlusion induced ischaemia, shown by lengthening in systolic strain in the LV apical anterior region (P<0.01) and concurrent changes in LAD accelerometer circumferential velocities during systole (P<0.01) and during the isovolumic relaxation phase (P<0.01). The changes in accelerometer circumferential velocities during LAD occlusion were greater compared with the changes during the interventions on global function (P<0.01). For the LAD accelerometer circumferential velocities, sensitivity was 94-100% and specificity was 92-94% in detecting ischaemia. CONCLUSIONS: Myocardial ischaemia can be detected with epicardial three-axis accelerometers. The accelerometer had the ability to distinguish ischaemia from interventions altering global myocardial function. This novel technique may be used for continuous real-time monitoring of myocardial ischaemia during and after cardiac surgery.

Syndecan-1 plasma levels during coronary artery bypass surgery with and without cardiopulmonary bypass.

The glycocalyx covering the endothelium is shed during ischemia and reperfusion. The shedding is accompanied by increased levels of the glycocalyx component syndecan-1 in the circulation. Our aim was to compare plasma levels of syndecan-1 in patients undergoing coronary artery bypass grafting (CABG), with or without the use of cardiopulmonary bypass (CPB). Syndecan-1 plasma concentrations were measured in patients undergoing CABG on-pump (nA =A 22) or off-pump (nA =A 22). The syndecan-1 concentration increased significantly from 29.5 +/- 4.6 ng/mL at baseline to 98.7 +/- 9.8 ng/mL (pA

New biomarkers in an acute model of live Escherichia coli-induced sepsis in pigs.

We developed a live Escherichia coli model of acute sepsis in pigs with emphasize on biomarkers reflecting the early inflammatory response of sepsis. Healthy pigs, 25-35 kg, were challenged intravenously (IV) (n = 12) or intrapulmonary (n = 6) with live E. coli and observed for 3 and 5 h respectively. Control pigs received culture medium (n = 6 + 3). Haemodynamic parameters and a broad panel of inflammatory mediators were measured. The dose of bacteria was carefully titrated to obtain a condition resembling the early phase of human septic shock. The IV group displayed a pro-inflammatory response [significant increase in tumour necrosis factor-alpha, interleukin (IL)-6 and IL-8] and an early anti-inflammatory response (significant increase in IL-10). For the first time, we demonstrate a significant increase in IL-12 and matrix metalloproteinase-9 (MMP) early in pig sepsis. Coagulation was activated (significant increase in thrombin-antithrombin complexes) and there was a significant decrease in the serum proteins suggesting capillary leakage. Haemodynamic parameters reflected a septic condition with significant decrease in systemic blood pressure, increases in heart rate, pulmonary artery pressure and base deficit. None of these changes was observed in the control group. Interleukin-1beta and vascular endothelial growth factor increased in both groups. Nitric oxide measurements suggested an initial pulmonary vascular endothelial inflammatory response. The intrapulmonary group, which did not resemble septic condition, showed a substantial increase in MMP-9. In this porcine model of sepsis, IL-12 and MMP-9 were detected for the first time. These biomarkers may have an impact in the understanding and future treatment of sepsis.

[High-intensity focused ultrasound ablation, a new method for the minimally invasive treatment of hepatic tumours].

High-intensity focused ultrasound (HIFU) is a new totally noninvasive treatment of liver neoplasms allowing for selective ablation of the neoplastic tissue. It was first described in the 1920s but attracted more attention only in the 1990s when the possibility of high-quality three-dimensional monitoring substantially improved efficiency of diagnostic ultrasound scanning and magnetic resonance imaging. Numerous experimental and clinical studies demonstrated the safety of the method and its applicability to the treatment of oncological patients. This review highlightens the principles of HIFU, describes the equipment for HIFU and the current state of investigations with the use of this technique with special reference to hepatic tumours. Prospects for the further development of HIFU are outlined.

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.

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.

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.

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.

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.

Measurements of heart motion using accelerometers.

We have used acceleration sensors to monitor the heart motion during surgery. A three-axis accelerometer was made from two commercially available two-axis sensors, and was used to measure the heart motion in anesthetized pigs. The heart moves due to both respiration and heart beating. The heart beating was isolated from respiration by high-pass filtering at 1.0 Hz, and heart wall velocity and position were calculated by numerically integrating the filtered acceleration traces. The resulting curves reproduced the heart motion in great detail, noise was hardly visible. Events that occurred during the measurements, e.g. arrhythmias and fibrillation, were recognized in the curves, and confirmed by comparison with synchronously recorded ECG data. We conclude that acceleration sensors are able to measure heart motion with good resolution, and that such measurements can reveal patterns that may be an indication of heart circulation failure.

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.

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.

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.

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.