Mansoor S. Khan

Measurement of surgical dexterity using motion analysis of simple bench tasks

The possibility of using quantitative motion analysis for objective assessment of simple surgical dexterity is investigated using the Imperial College Surgical Assessment Device (ICSAD) with qualitative analysis undertaken by inspection. Bench-top knot tying and suturing skills were performed and examined for the ability to discriminate between surgeons of varying experience. These exercises were found to discriminate significantly between junior and senior surgeons in terms of both time taken and the number of movements required. The relation between time and motion was found to be variable depending on what skill was being undertaken: simple suturing, suturing at depth, or knot tying (1.71 vs. 1.86 vs. 2.36; p = 0.002 for 1 vs. 2; p < 0.001 for others). When the number of movements in a minute (standardized movements per minute) were considered, both groups were found to work at a similar rate, depending on the task, implying that the more experienced surgeon is more economical, performing the same exercise with fewer moves rather than with higher speed. Motion analysis exhibits face and construct validity and is a reliable assessment of simple surgical dexterity. Its use for objective assessment of dexterity and competence should be encouraged.

Reducing the Morbidity From Extravasation Injuries

Extravasation is defined as the leakage of solutions from the vein. This may cause damage to surrounding tissue during intravenous fluid administration. Extravasation has an incidence of 5% of all cytotoxic drug administrations. In the authors’ hospital, a protocol has been set up using the dilution flush-out technique. Extravasation packs containing cannulae, normal saline, hyaluronidase, and instructions on how to manage extravasation injuries, accompanied by an audit sheet to assist follow-up, have been introduced to allow the treatment of extravasation at the ward level in an attempt to reduce morbidity from the injury. Between December 1997 and December 1999, 18 adult patients were identified with extravasation injuries after the administration of cytotoxic medication. Seventeen were treated immediately according to the protocol. One, however, was not. Patients were followed-up for 6 months after injury. The 17 patients treated immediately needed no further surgical intervention, whereas the 1 patient not treated needed a split skin graft to cover the defect. The authors recommend the placement of “extravasation packs” on all wards where cytotoxic drugs are prescribed and that all staff members are familiar with this regime. These steps help to reduce the morbidity of a potentially damaging injury.

Robotics in surgery

The drive to introduce operating robots into theaters is for a number of reasons related to their intrinsic properties: these include three-dimensional spatial accuracy, reliability, and precision, and in minimal-access surgery they aid the surgeon, who must contend with deficits in sensation and dexterity. There are a number of robots already in clinical use, in neurosurgery and orthopaedics, that possess these traits and can be used once the area to be removed or biopsied has been highlighted. In one particular area there has been a rapid expansion in the commissioning and use of surgical robots: that of the telemanipulators. The introduction of the telemanipulators in minimal-access surgery has restored the loss of dexterity and visual quality that is inherent in minimalaccess surgery, allowing for more complex procedures to be undertaken with a high degree of quality. This article will consider the history of robots in surgery and their current use with particular reference to these systems. The robot has been defined as “a reprogrammable multifunctional manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks” by the Robot Institute of America. Webster defines them as “an automated device that performs functions normally ascribed to humans or a machine in the form of a human.” The term robotics refers to the study and use of robots. The word robot was first introduced in Karel Capek’s play “Rossum’s Universal Robots,” which opened in Prague in 1921. This play concerned the dehumanization of man in a technological civilization, and the robots were created by chemical rather than mechanical means. The word robotics refers to the study and use of robots and was first used by Isaac Asimov in his short story “Runaround”, later proposing the Laws of Robotics (Table 1). His laws refer to the protection of humanity above humans, that robots must obey humans unless it conflicts with a higher law. These principles of safety, initially raised by Asimov, will be considered later, especially with reference to public education. The first industrial robots were the Unimates developed by George Devol and Joe Engelberger in the late 1950s and early 1960s. The robotics industry expanded rapidly in the 1980s with their use in production lines of the automotive industry, followed by a relative collapse and recent regrowth of the industry. The move of robots into surgery has occurred in the last twenty years with a recent rapid expansion related to cost and computing power. There is an important distinction to be made between computer aided surgery (CAS) and robotic surgery. In CAS, the surgeon generally holds the tools and computers might help in planning and positioning, but in robotic surgery, robots will hold tools, providing greater accuracy and precision. The majority of these computer-based systems are tracking systems, tracking a tool or a part of the anatomy. The tracking system can be sensor-based—eg, light-emitting diodes or optical reflectors mounted on the tool—or if anatomy is being tracked, then three-dimensional modelling by radiographic means will be required. These anatomic reference maps require either obvious anatomical markers or artificial markers known as fiducials. The power for the tools comes from the surgeon. Obviously, there must be careful preoperative planning and the preoperative images of the patient must accurately match the intraoperative position of the patient. The use of robots in medicine can be broadly divided into rehabilitation, service, and surgery (including ancillary devices such as microscopes). Their use in rehabilitation and for assisting disNo competing interests declared.

Assessing surgical skill using bench station models.

Background: The acquisition of surgical skill is one of the essentials of good surgical practice. The training of plastic surgeons is presently unstructured, with few objective measures of surgical skill. The trainee’s time to acquire skills may be inadequate because of the shortened time for training with the Calman system. There is also increasing pressure from the government to introduce testing of surgical competency for all surgeons. The authors introduce a series of tasks that allow assessment of technical skill among plastic surgical trainees. Methods: A range of surgeons with differing surgical skill were tested. They performed three tasks designed to assess their ability to suture skin, take a medium-thickness skin graft, and repair a tendon. The candidates were videotaped during the procedures and scored by four independent observers using the Objective Structured Assessment of Technical Skill scoring system. Each candidate was then given an overall competence score. Results: Sixty-five candidates were tested with an experience range from consultant to junior senior health officer. Results showed significant differences down the grades, with consultants performing the tasks with greater competency than their juniors (p = 0.004). Conclusions: The authors have demonstrated a valid and reliable method of objectively measuring the surgical skill of plastic surgical trainees. The authors have shown that consultants perform better than the juniors and that the tasks are easily reproduced. This has implications for future assessment in that these tests may be used as formal assessment programs for testing and teaching trainees throughout their careers.

Technical performance: Relation between surgical dexterity and technical knowledge

Technical performance consists of surgical knowledge, judgment, and dexterity. Although assessment of surgical dexterity is now possible, assessing technical knowledge and its relation to dexterity has not been elucidated. Surgeons of varying experience were recruited to the skills laboratory to undertake three assessments: simple surgical dexterity (at 14 stations scored by motion analysis), an operating room equipment examination, and a novel error analysis. The scores were correlated, and p < 0.05 was deemed to be significant. Thirty surgeons were recruited; and construct validity was exhibited in all areas. Correlations were shown to exist between the two knowledge examinations (Spearman’s rho = 039). Correlations existed between all dexterity task parameters and the equipment examination, whereas they existed for only 15 of the 28 parameters of the error examination and were always weaker. The stronger correlations between dexterity and instrument and operating room (OR) equipment reflect greater surgical experience and time spent in the OR. The weaker correlations between the error analysis and dexterity suggest that these skills are learned at different times. The identification of common surgical errors should be more formally taught to ensure greater uniformity.RésuméLes performances techniques comportent des éléments de connaissances chirurgicales, du jugement et de dextérité. Alors que l’évaluation de la dextérité chirurgicale est actuellement possible, celle des connaissances techniques et son rapport avec la dextérité n’ont pas encore été élucidés. Des chirurgiens, d’expérience variée, ont entrepris trois évaluations séparées en laboratoire de dextérité: dextérité chirurgicale simple (14 stations comportant un score par analyse des mouvements), un examen portant sur l’équipement opératoire et une analyse d’erreurs. On a corrélé les scores réalisés entre eux. Une valeur p = 0.05 a été considérée comme significative. 30 chirurgiens ont été recrutés et une validité de construction a été retrouvée dans tous les domaines. On a montré une corrélation entre les deux investigations explorant les connaissances (coefficient de Spearman’s rho = 0.39). On a mis en évidence une corrélation entre tous les paramètres de dextérité et l’examen concernant l’équipement, alors que cette corrélation n’existait que pour 15 des 28 paramètres dans l’analyse des erreurs et le coefficient de corrélation a toujours été moins élevé. Les corrélations les plus fortes entre la dextérité et l’analyse de l’équipement de la salle d’opération reflètent une expérience chirurgicale plus importante et un temps passé en salle d’opération plus long. Les corrélations plus faibles entre l’analyse d’erreur et la dextérité suggèrent que l’adresse des gestes est acquise à des moments différents. L’identification des erreurs les plus fréquentes devrait être formalisée pour assurer une meilleure uniformisation de la formation.ResumenEl desempeño técnico quirúrgico depende del conocimiento, el juicio y la destreza. En tanto que la evaluación de la destreza hoy es factible, la evaluación del conocimiento técnico y su relación con la destreza todavía no ha sido elucidada. Se incluyeron cirujanos con diversos grados de experiencia para realizar 3 tipos de evaluación en el laboratorio de habilidades quirúrgicas: destreza quirúrgica simple (más de 4 estaciones, evaluadas por análisis de movimiento), un examen de equipo de salas de cirugía y un análisis de error novel. Se hizo la correlación de los resultados, dando valor significativo a una p de 0.05. Se incluyó un total de 30 cirujanos y se registró la validez de construcción en todas las áreas. Se demostró la existencia de correlaciones en 2 exámenes de conocimiento (rho = 039 de Spearman). Aparecieron correlaciones entre todos los parámétras de tareas de destreza y los exámenes de equipo, pero sólo apareció en 15 de los 28 parámetras del examen de error y éstas fueron consistentemente más débiles. Las más fuertes correlaciones entre la destreza y el instrumente y el equipo de salas de cirugia reflejan mayor experiencia quirurgica y mayor tiempo de trabajo en las salas de cirugía. Las débiles correlaciones entre el análisis de error y la destreza sugieren que estas habilidades pueden ser adquiridas en diferentes épocas. La identificatión de errores quirúrgicos comunes debería ser ensenada de manera más formal con el fin de lograr una mayor uniformidad.