Recurrent groin hernia - Outcome after surgery

Background: According to the Swedish Hernia Register (SHR), the reoperation rate after recurrent groin hernia is more than twice that following primary hernia repair. Aims: To study the impact of method of mesh repair used in recurrent groin hernia surgery on re-recurrence as well as chronic pain and physical disability. Methods: Papers 1 and 2 were based on nationwide data from the SHR 1992-2008. In Paper 1 the cumulative risk for reoperation was studied after repeated surgery for recurrent hernia. In Paper 2 the risk for reoperation was analysed in relation to the mesh method used for recurrent hernia repair, taking the previous (index) repair into account. Papers 3 and 4 were based on a cohort of 1st and 2nd recurrent repairs performed at 5 hospitals in the south-west region of Sweden 1998-2007. A follow-up was performed 2009 using the Inguinal Pain Questionnaire (IPQ) and a selective clinical examination. In Paper 3 the risk for a 2nd recurrence was studied in relation to Anterior (AMR) and Posterior Mesh Repairs (PMR) and in Paper 4 the hazard ratio for chronic pain and physical disability was studied in relation to type of mesh repair and mean surgeon´s annual volume. Results: Paper 1 The risk for a further reoperation increased with the number of recurrent repairs (p 5 O-PMR correlated with a lower risk for chronic pain compared to an surgeon´s annual volume ≤ 5 (OR 0.42 (CI 0.19-0.94), p=0.034). Having a 2nd recurrent repair was associated with a higher risk for chronic pain compared to a 1st recurrent repair (OR 2.89 (CI 1.21-6.88), p=0.017). Conclusions: A posterior mesh repair for recurrent groin hernia surgery was associated with a lower 2nd recurrence rate compared to anterior mesh repair. A posterior mesh repair for the 1st recurrent operation is recommended after an anterior index repair and an anterior mesh repair after a posterior index operation. Endoscopic repairs have the lowest risk for both a 2nd recurrence and chronic groin pain and physical disability. An O-PMR performed trough a Nyhus incision is preferred and the TIPP procedure should be avoided. An surgeon´s annual volume > 5 O-PMR resulted in a lower 2nd recurrence rate and a lower risk for chronic pain. The risk for further recurrence increases with increasing number of groin hernia operations and the risk for chronic pain increases after a 2nd recurrent repair

Estimating Relative Position and Orientation Based on UWB-IMU Fusion for Fixed Wing UAVs

In recent years, the interest in flying multiple Unmanned Aerial Vehicles (UAVs) in formation has increased. One challenging aspect of achieving this is the relative positioning within the swarm. This thesis evaluates two different methods for estimating the relative position and orientation between two fixed wing UAVs by fusing range measurements from Ultra-wideband (UWB) sensors and orientation estimates from Inertial Measurement Units (IMUs). To investigate the problem of estimating the relative position and orientation using range measurements, the performance of the UWB nodes regarding the accuracy of the measurements is evaluated. The resulting information is then used to develop a simulation environment where two fixed wing UAVs fly in formation. In this environment, the two estimation solutions are developed. The first solution to the estimation problem is based on the Extended Kalman Filter (EKF) and the second solution is based on Factor Graph Optimization (FGO). In addition to evaluating these methods, two additional areas of interest are investigated: the impact of varying the placement and number of UWB sensors, and if using additional sensors can lead to an increased accuracy of the estimates. To evaluate the EKF and the FGO solutions, multiple scenarios are simulated at different distances, with different amounts of changes in the relative position, and with different accuracies of the range measurements. The results from the simulations show that both solutions successfully estimate the relative position and orientation. The FGO-based solution performs better at estimating the relative position, while both algorithms perform similarly when estimating the relative orientation. However, both algorithms perform worse when exposed to more realistic range measurements. The thesis concludes that both solutions work well in simulation, where the Root Mean Square Error (RMSE) of the position estimates are 0.428 m and 0.275 m for the EKF and FGO solutions, respectively, and the RMSE of the orientation estimates are 0.016 radians and 0.013 radians respectively. However, to perform well on hardware, the accuracy of the UWB measurements must be increased. It is also concluded that by adding more sensors and by placing multiple UWB sensors on each UAV, the accuracy of the estimates can be improved. In simulation, the lowest RMSE is achieved by fusing barometer data from both UAVs in the FGO algorithm, resulting in an RMSE of 0.229 m for the estimated relative position

Estimating Relative Position and Orientation Based on UWB-IMU Fusion for Fixed Wing UAVs

In recent years, the interest in flying multiple Unmanned Aerial Vehicles (UAVs) in formation has increased. One challenging aspect of achieving this is the relative positioning within the swarm. This thesis evaluates two different methods for estimating the relative position and orientation between two fixed wing UAVs by fusing range measurements from Ultra-wideband (UWB) sensors and orientation estimates from Inertial Measurement Units (IMUs). To investigate the problem of estimating the relative position and orientation using range measurements, the performance of the UWB nodes regarding the accuracy of the measurements is evaluated. The resulting information is then used to develop a simulation environment where two fixed wing UAVs fly in formation. In this environment, the two estimation solutions are developed. The first solution to the estimation problem is based on the Extended Kalman Filter (EKF) and the second solution is based on Factor Graph Optimization (FGO). In addition to evaluating these methods, two additional areas of interest are investigated: the impact of varying the placement and number of UWB sensors, and if using additional sensors can lead to an increased accuracy of the estimates. To evaluate the EKF and the FGO solutions, multiple scenarios are simulated at different distances, with different amounts of changes in the relative position, and with different accuracies of the range measurements. The results from the simulations show that both solutions successfully estimate the relative position and orientation. The FGO-based solution performs better at estimating the relative position, while both algorithms perform similarly when estimating the relative orientation. However, both algorithms perform worse when exposed to more realistic range measurements. The thesis concludes that both solutions work well in simulation, where the Root Mean Square Error (RMSE) of the position estimates are 0.428 m and 0.275 m for the EKF and FGO solutions, respectively, and the RMSE of the orientation estimates are 0.016 radians and 0.013 radians respectively. However, to perform well on hardware, the accuracy of the UWB measurements must be increased. It is also concluded that by adding more sensors and by placing multiple UWB sensors on each UAV, the accuracy of the estimates can be improved. In simulation, the lowest RMSE is achieved by fusing barometer data from both UAVs in the FGO algorithm, resulting in an RMSE of 0.229 m for the estimated relative position

Miksi teemme englanninkielisistä korkeakouluopinnoista saavutettavia ja tarkoituksenmukaisia maahanmuuttajille?

Jo lähes kymmenen viime vuoden ajan Suomen väestön kasvu on ollut ainoastaan maahanmuuton varassa. Lisäksi nopeasti vanheneva väestönrakenne ja työikäisen väestön väheneminen kasvattavat muualta tulleiden työntekijöiden tarvetta. Samalla yhteiskunnan ja hyvinvoinnin kehittyminen edellyttävät osaamistason nousua, ja Suomella on OECD-maista suurin pula korkeakoulutetuista työntekijöistä

Changing the path of inguinal hernia surgery decreased the recurrence rate ten-fold. Report from a county hospital

Objective: To audit the effect of changes in treatment of inguinal hernias on recurrence rate. Design: Retrospective analysis of consecutive patients operated on in 1990 and prospective analysis of consecutive patients operated on in 1996. Follow up with questionnaire followed by selective clinical examination. Setting: County hospital, Sweden. Subjects: 144 patients with 147 inguinal hernias operated on in 1990 and 154 patients with 165 inguinal hernias operated on in 1996. Interventions: In 1993, we changed many aspects of the treatment of inguinal hernia. We introduced new techniques such as Shouldice, Lichtenstein, and laparoscopic hernia repair. Non-absorbable polypropylene sutures replaced the braided absorbable sutures previously used. Inguinal herniorrhaphy went from a "low status" operation to a high status operation and became a primary teaching operation for surgical residents. Main outcome measures: Recurrence rate at 5 year follow up. Results: The 5 year recurrence rate decreased from 28% in 1990 to 3% in 1996 (p < 0.001). The median operating time increased from 35 minutes in 1990 to 78 minutes in 1996 (p < 0.001). Conclusion: Changing the strategy of inguinal hernia surgery by introducing uniform operating techniques and new materials dramatically improved the results and allowed us to achieve recurrence rates comparable to those seen in specialised hernia centres

Simball Box for Laparoscopic Training With Advanced 4D Motion Analysis of Skills.

Laparoscopic skills training and evaluation outside the operating room is important for all surgeons learning new skills. To study feasibility, a video box trainer tracking 4-dimensional (4D) metrics was evaluated as a laparoscopic training tool

Extended score interval in the assessment of basic surgical skills.

The Basic Surgical Skills course uses an assessment score interval of 0-3. An extended score interval, 1-6, was proposed by the Swedish steering committee of the course. The aim of this study was to analyze the trainee scores in the current 0-3 scored version compared to a proposed 1-6 scored version

Impact of operative time and surgeon satisfaction on the long-term outcome of hernia repair

The aim of this study was to assess the impact of the degree of difficulty and quality of hernia repair, as perceived by the surgeon, and operative time on the reoperation rate. All hernia repairs performed during the period 1994-1995 at the Department of Surgery, University Hospital of Lund, Sweden, were recorded prospectively. The degree of difficulty and the degree of difficulty in relation to the preoperative expectation of the surgeon were graded on a three-degree scale, the final outcome graded as optimal or suboptimal, and the time required to perform the hernia repair was recorded. Recurrence repairs prior to 1998 were traced in a retrospective review of the patient notes. The Swedish Hernia Register was checked for reoperations from 1998 and later. Altogether, 184 hernia repairs were recorded during the study period, including 14 repairs on women. The mean age of the patients was 58 years and the standard deviation was 15 years. Subsequent reoperation for recurrence was identified in 21 (11.4%) of these patients. The operative time correlated significantly with the surgeon's perception of the degree of difficulty (P < 0.05). Operative time less than 20 min (n = 4) was significantly associated with increased risk for reoperation (P < 0.05). The degree of difficulty, the degree of difficulty in relation to preoperative expectation, and the assessment of the final outcome were not associated with the risk for reoperation. Although neither the grade of difficulty nor the surgeon's perception of the quality of repair significantly predicted the final outcome, the risk for reoperation increased if the repair was performed rapidly