Analysis of the quality and efficiency in learning laparoscopic skills.

OBJECTIVES: This study demonstrates the application of time-action analysis to the evaluation of task performance of diagnostic laparoscopy with laparoscopic ultrasonography. METHODS: The first 25 diagnostic laparoscopies with laparoscopic ultrasonography performed by a surgical resident were analyzed and compared with the outcomes of these procedures performed by an experienced surgeon. The time, actions, and correctness of task performance were evaluated. Furthermore, outcome correctness and postoperative complications were assessed. RESULTS: No postoperative complications occurred. The resident made one wrong diagnosis, for which the cause was detected by peroperative analysis. Additionally, 1% of the subtasks were performed only partially, 4% not at all, and 2% using the wrong technique. The efficiency for most diagnostic tasks remained significantly lower than that of the experienced surgeon (p < 0.001). CONCLUSIONS: Time-action analysis can be used to provide detailed insight into the quality and efficiency of learning surgical skills. It enables objective measurement of correctness in task performance as well as time and action efficiency.

Peroperative analysis of the surgical procedure.

The increased technological complexity of surgery and the growing importance of quality assessment demand objective analysis of the surgical process. However, until now no standard method existed for analyzing the peroperative process. In this article, a methodology is discussed to describe and to analyze the surgical process. A method is given to measure the correctness and efficiency of task performance, protocols, and instruments used. In addition, reference values are defined so as to compare new instruments, alternative protocols, and the performance of new tasks with a standard. Finally, recommendations are given for improving new surgical tasks, the development of clinically driven instrument design, and new protocols.

Efficiency of manual versus robotical (Zeus) assisted laparoscopic surgery in the performance of standardized tasks.

BACKGROUND: The objective of this study was to compare the efficiency of manual and robotically assisted laparoscopic surgery. METHODS: To evaluate the surgical efficiency in a set of basic endoscopic movements, 20 medical students without any surgical experience were selected to perform at random a set of laparoscopic tasks either manually or robotic assisted (Zeus). This task consisted of dropping beads into receptacles, running a 25-cm rope, capping a hypodermic needle, suturing, and performing a laparoscopic cholecystectomy on a cadaver liver of a pig. A quantitative time-action analysis was performed to evaluate the efficacy and skill performance in terms of time and the number of actions. RESULTS: The dropping beads exercise and the laparoscopic cholecystectomy required more time when performed with robotic assistance, as compared with manual performance (respectively, median, 78.5 s; range, 63 - 122 s vs median, 144.5 s; range, 100 - 169 s; p <0.01 and median, 34.0 min; range 11-44 min vs median, 46.5 s; range, 21 - 79 min; p = 0.05). A tendency toward fewer total actions in all the robotically assisted exercises was observed. However, significance was shown only in the rope-passing task (median, 71; range, 59 - 87 vs median, 62; range, 57-80; p = 0.05). Grasping the beads, the rope, and either the needle or the cap were tasks that required fewer actions to complete when performed with robotically assistance (respectively, median, 11; range, 10 - 14 vs median, 12.5; range, 11 - 15; p <0.01; median, 56; range, 55 - 60 vs median, 60.5 min; range, 55 - 65; p = 0.03, and median, 6; range, 4 - 21 vs median, 10.5; range, 6 - 38; p = 0.02). As compared with the robotically assisted rope-passing exercise, more failures were made in the manually performed procedure (p = 0.03), mainly caused by unintentional dropping of the rope (p = 0.02). CONCLUSIONS: Robotically assisted laparoscopic surgery by participants without any surgical experience might require more time, but actions can be performed equally or more precisely as compared with manual laparoscopic surgery.

Time-action analysis of instrument positioners in laparoscopic cholecystectomy.

BACKGROUND: Instrument positioners can position and lock a laparoscopic instrument. This study uses time-action analysis to evaluate objectively whether IPs can substitute for a surgical assistant efficiently and safely. METHODS: In four hospitals, 78 laparoscopic cholecystectomies were randomly assisted by a surgical assistant or an instrument positioner (AESOP and PASSIST) The efficiency and safety of laparoscopic cholecystectomies were analyzed with respect to time, number and type of actions, positioning accuracy, and peroperative complications. A questionnaire evaluated the difficulties for each operation and the comfort of instrument positioner use. RESULTS: The PASSIST and AESOP were able to replace the surgical assistant during laparoscopic cholecystectomies without significantly changing either the efficiency or the safety of the operation. The questionnaire showed that the surgeons preferred to operate with an instrument positioner. CONCLUSION: This study assessed objectively that instrument positioners can substitute for a surgical assistant efficiently and safely in elective laparoscopic cholecystectomies.

Design and feasibility of PASSIST, a passive instrument positioner.

BACKGROUND AND PURPOSE: During minimally invasive procedures, an assistant controls the camera and often a laparoscopic grasper. Ideally, the surgeon should be able to manipulate the instruments because the indirect way of control complicates the surgeon's observation and actions and disturbs eye-hand coordination. Reported replacements for the assistant are active positioners, "robots," such as the Aesop and the EndoAssist. Because positioning instruments is often a static task, the Academic Medical Center has developed a passive assistant for instrument positioning (PASSIST) to allow solo surgery. METHODS: The PASSIST was designed to be simple, fully autoclavable, slender, and stiff. The joints have adjustable friction and spring compensation for stabilizing the instrument in a fixed position, enabling intuitive single-hand repositioning. RESULTS: The PASSIST has been tested in three laparoscopic procedures: cholecystectomy, laparoscopically assisted vaginal hysterectomy, and spondylodesis. In all of these procedures, the assistant could be replaced satisfactorily, and the surgeon was able to manipulate all of the instruments on his own. CONCLUSION: Solo surgery using the PASSIST is feasible. The positioner enables the surgeon to manipulate the viewpoint, to have a stable image, and therefore to improve observation and manipulating actions.

Comparison of efficiencies of three techniques for colon surgery.

PURPOSE: To determine the most efficient technique for performing a colectomy, we used the methodology of time-motion analysis. METHODS: The efficiency of five hand-assisted and six regular laparoscopic colectomies and one open colectomy, performed by four surgeons in three different hospitals, was measured. The open colectomy was analyzed as a reference procedure. RESULTS AND CONCLUSIONS: The hand-assisted laparoscopic technique was the most efficient. Hand-assisted laparoscopy was therefore less time consuming than laparoscopic surgery. Open surgery was the fastest technique, because the time for every surgical motion is a factor of three shorter than for the two laparoscopic techniques.

Problems with laparoscopic instruments: opinions of experts.

INTRODUCTION: Laparoscopic surgery is particularly known for its complex technique, which calls for operative analysis of laparoscopic instruments. This study investigates the opinion of experts about clinical problems with instruments occurring during laparoscopic surgery. METHODS: A questionnaire was used to obtain the opinions of expert laparoscopic surgeons about difficulties experienced operatively using laparoscopic instruments. RESULTS: The laparoscopic surgeons indicated that coagulators were especially prone to cause complications of the gastro-intestinal tract, vascular injuries, and bile duct injuries. Dissectors were considered to play a role in the occurrence of solid organ and bile duct injuries, and retractors to cause solid organ injuries. Insufficient functionality of the instruments and insufficient quality of the image were indicated to contribute to the instrument's risks. CONCLUSION: The questionnaire identified technological deficiencies prone to cause operative complications. The results provide a basis for the interaction between surgeons and engineers, and serve as pilot information on which to base an in-depth object evaluation of instrument problems.

Establishment of pneumoperitoneum with a modified blunt trocar.

Veress needle and trocar-related accidents have caused many surgeons to adopt the Hasson technique for establishment of pneumoperitoneum, but this technique also has drawbacks. A modification of the sharp trocar has been developed that overcomes the disadvantages of the Veress needle and Hasson trocar.

Efficacy of establishment of pneumoperitoneum with the Veress needle, Hasson trocar, and modified blunt trocar (TrocDoc): a randomized study.

PURPOSE: To compare three techniques of establishment of pneumoperitoneum for efficacy: the Veress needle/first trocar, the Hasson trocar, and a newly developed modified blunt trocar, the TrocDoc. PATIENTS AND METHODS: Between June and December 1999, 62 patients eligible for laparoscopic surgery were randomized. The effectiveness of installation of the pneumoperitoneum using the three techniques was assessed by time-motion analysis. Primary efficacy measures were total time and number of actions required to establish the pneumoperitoneum. Secondary efficacy measures were procedure-related complications, wound complications, and occurrence of CO2 leakage. RESULTS: Two patients were withdrawn from inclusion. The three groups were comparable for age and body mass index. Total time was shortest using the TrocDoc rather than the Veress needle/first trocar and the Hasson trocar (respectively, 138 +/- 58 v 237 +/- 56 v 350 +/- 103 seconds), and the number of actions was lowest for the Veress needle/first trocar combination: 22 +/- 7 v 32 +/- 12 (TrocDoc) v 53 +/- 17 (Hasson). There was no morbidity related to the installation of pneumoperitoneum nor trocar wound complications. Gas leakage occurred in five of the Hasson introductions. CONCLUSIONS: Establishment of the pneumoperitoneum is more efficient using the TrocDoc compared with the Veress needle/first trocar and the Hasson trocar. The TrocDoc might replace the two alternatives because of its efficacy and open method of introduction.

Quantitative analysis of the functionality and efficiency of three surgical dissection techniques: a time-motion analysis.

The increasing technological complexity of surgery demands objective evaluation of surgical techniques. In particular, alternatives for laparoscopic ligation, such as monopolar coagulation and the relatively new bipolar scissors combining dissection with coagulation, should be analyzed and compared. This study tests the efficacy of quantitative time-motion analysis in evaluating and comparing the functionality and efficiency of dissection and ligation techniques in a clinical setting. Standard dissection with ligation of vessels, bipolar scissors, and monopolar coagulation were consecutively applied to dissect 4 of the small bowel mesentery of pigs, in random order. All actions performed were recorded and analyzed, using a standard action list. The efficiency of each technique was expressed in mean dissection time and number of actions, and the safety in occurrence of complications and severity of microscopic damage. Time-motion analysis evaluated the efficiency objectively and reproducibly (ICC 0.98). Bipolar scissors were significantly more efficient (time 7 +/- 2 min, actions 129 +/- 33) than the standard technique (28 +/- 6, 771 +/- 185) and monopolar coagulation (14 +/- 5, 368 +/- 32) (p < 0.01). Furthermore, bipolar coagulation needed significantly less recoagulation of an oozing vessel (0.5% of the total dissected vessels) than did monopolar coagulation (10.4%), and the damaged zone was significantly smaller (p < 0.05). Significantly less time was spent waiting or exchanging instruments with bipolar scissors than with the standard technique (p < 0.05). This time-motion analysis objectively compared the efficiency and functionality of three surgical dissection techniques during clinical use. Bipolar scissors were more efficient than were both other techniques, and they coagulated vessels more safely than did monopolar coagulation.

[Mortality rate in lung cancer decreasing in men and increasing in women]. / Sterfte door longkanker daalt bij mannen en stijgt bij vrouwen.

OBJECTIVE: To determine the trend in lung cancer mortality rates among men and women in the Netherlands during the period 1951 to 1992. DESIGN: Descriptive research. METHOD: In a previous paper the lung cancer mortality rates of men and women during the period 1951 to 1982 were analysed using the Netherlands Central Bureau of Statistics (CBS) population data and the CBS mortality data. The mortality rates were directly standardized for age using as a standard the Dutch sum population of 1951 to 1982. The current study describes the lung cancer mortality for men and women until 1992 using exactly the same methods. RESULTS: The direct standardized mortality rates for men had decreased since 1987. For women, on the contrary, these rates had increased further. The age-specific mortality rates for men have decreased since the calendar period 1983-1987 and since the birth cohort 1916-1920. The age-specific mortality rates for women have increased until the latest calendar period 1988-1992 and until the latest birth cohort 1931-1935. CONCLUSIONS: Lung cancer mortality in men has peaked, in women it is still rising.

Peroperative time-motion analysis of diagnostic laparoscopy with laparoscopic ultrasonography.

BACKGROUND: Advanced technology is being introduced rapidly into laparoscopic procedures, frequently without an accurate evaluation of its functioning. In this study, standardized time-motion analysis was applied to evaluate the peroperative surgical process and the technical equipment used in 18 cases of diagnostic laparoscopy with laparoscopic ultrasonography (DLLU). METHODS: The image through the laparoscope, the ultrasonograph and an overview of the operating theatre were recorded simultaneously. The time for each phase, efficient actions (e.g. identifying lesions by inspection, making an ultrasonogram or taking a biopsy) and limiting factors (e.g. technical problems, time spent waiting) were determined, and a current standard was defined. RESULTS: Of the actions performed, 52 per cent were qualified as efficient, 17 per cent were classified as time spent waiting for personnel, instruments were positioned in 13 per cent, and unnecessary instrument exchanges were involved in 10 per cent. The evaluation led to a significant reduction in delay times and resulted in design criteria for improved biopsy instruments. The current standard was calculated from the mean time and number of actions determined for each phase. CONCLUSION: This time-motion study provided detailed insight into the peroperative process of DLLU, leading to improvements in the surgical process and instruments used. The defined current standard will enable evaluation of the learning curve and new technologies.

Sensitivity of laparoscopic dissectors. What can you feel?

BACKGROUND: Sensory feedback is reduced considerably in minimally invasive procedures by the interposition of instruments, causing loss of direct manual contact with the tissue. The purpose of this study was to evaluate the feedback quality of commercially available reusable and disposable laparoscopic dissectors. METHODS: A total of 31 participants were asked to feel a simulated arterial pulse with their bare fingers and through laparoscopic dissectors, tweezers, an orthopedic forceps, and a laparoscopic low-friction prototype. The absolute sensory threshold was determined by the psychophysical method of limits. RESULTS: The sensory feedback quality was significantly better for the reusable dissectors tested than for the disposable dissector (p < 0.001). Nevertheless, the reusable dissectors were at least eight times less sensitive than bare fingers. Furthermore, sensitivity qualities were highly variable, depending on the dissector tested. CONCLUSIONS: This study showed that the overall sensitivity loss through instruments could be accurately assessed, proving that the sensory feedback for commercially available instruments was low compared to bare fingers. The good sensory feedback results of the prototype indicated that careful design could decrease the overall sensitivity loss.