Paul J. Gorman

Tactile feedback is present during minimally invasive surgery

BACKGROUND The applications of minimally invasive surgery (MIS) and laparoscopy are rapidly expanding. Despite this expansion, our understanding of the importance of haptic feedback during laparoscopic surgery is incomplete. Although many surgeons believe that the use of minimally invasive techniques eliminates force feedback and tactile sensation (haptics), the importance of haptics in MIS has not been fully evaluated. There is considerable interest in the development of simulators for MIS even though the importance of force feedback remains poorly understood. This study was designed to determine the ability of experienced surgeons to interpret haptic feedback with respect to texture, shape, and consistency of an object. STUDY DESIGN A randomized, single-blinded study was designed. Twenty surgeons were presented objects in a random order, with participants blinded as to their identity. Inspection by direct palpation, conventional instruments, and laparoscopic instruments was performed on all objects. Statistic analysis of the data was performed using chi-square analysis and, when appropriate, a Fischer exact probability test. RESULTS Direct palpation was associated with the highest accuracy for shape identification and was superior to both conventional instruments (p < 0.001) and laparoscopic instruments (p<0.001). Fine texture analysis with either a conventional instrument or a laparoscopic instrument was superior to direct palpation (p < 0.05). Finally, the three methods of analysis were comparable for consistency analysis. CONCLUSIONS These data indicate that laparoscopic instruments do, in fact, provide surgeons with haptic feedback. Interpretation of the texture, shape, and consistency of objects can be performed. In some situations, laparoscopic instruments appear to amplify the haptic information available. Our ongoing work is directed at further defining force interactions.

Incidence of operative procedures on cleft lip and palate patients.

The incidence of operative procedures in a group of 374 cleft lip and palate patients was determined by a chart review. These patients were part of a long term study funded by the National Institute of Dental Research at the Lancaster Cleft Palate Clinic. The chart review provided a breakdown of the primary and secondary procedures performed on the patients. Although the secondary procedures carried out were underestimated in this study, it is clear that these operations comprise a major component of the successful treatment of these patients. The results of the study and the implications in todays managed care environment are discussed.

Practical training for postgraduate year 1 surgery residents

BACKGROUND Surgical interns accept significant patient care responsibilities with minimal orientation. We have developed a multifaceted training program for incoming surgical interns in which learning in a simulated environment plays a key role. The purpose of this study was to evaluate resident perceptions of simulated clinical calls as an educational modality and to measure the effect on self-ratings of confidence. METHODS A multidisciplinary team compiled 15 clinical scenarios. Simulated nurse-to-resident clinical call sessions were held on 3 separate days. Daily course evaluation surveys and identical precourse and postcourse confidence surveys were completed. RESULTS The resident confidence measure increased significantly postcourse (6.73 versus 8.35, P <0.03). The evaluation survey score averaged 4.35 out of 5. CONCLUSIONS Simulated clinical call sessions were well received and resulted in a significant increase in resident confidence levels. Based on this modalitys apparent efficacy and ease of implementation, we offer it as a useful educational tool for incoming postgraduate year-1 surgical residents.

Video microsurgery : Evaluation of standard laparoscopic equipment for the practice of microsurgery

Traditional microsurgery involves the use of bulky and expensive stereo microscopes that have limited portability. Recent advances in video technology have enabled the exploration of alternative visualization methods. The purpose of this study was to evaluate standard laparoscopic equipment for microvascular anastomoses. Eight surgeons completed anastomoses on rat femoral and synthetic vessels using stereo microsurgery and video microsurgery visualization systems. All surgeons had previous experience with stereo microsurgery and none had ever used video microsurgery. Data were collected on overall anastomosis and individual suture times. A sample of completed anastomoses was placed in a video database and evaluated by use of a quality rating scale (8 to 10, excellent; 6 to 7, adequate; less than 6, poor). All surgeons subjectively evaluated the video microsurgery system. A total of 48 anastomoses were completed. The average total anastomosis time for the stereo microsurgery was 1018.9 ± 463.2 seconds versus 1738.9 ± 460.1 seconds for the video microsurgery. The average individual suture placement time was 114.6 ± 60.6 seconds for the stereo microsurgery versus 211.7 ± 128.4 seconds for the video microsurgery (p < 0.05). Twenty‐five of the anastomoses underwent quality review. The overall score of the stereo microsurgery group was 8.1 ± 1.7, and the video microsurgery group had an overall score of 7.3 ± 1.6. Survey results revealed that 75 percent of the participants thought that the video microsurgery would be useful for human operations and would improve surgeon comfort, but 87.5 percent would not use the present video microsurgery system over stereo microsurgery in their practice. Although significant differences exist in overall anastomosis and individual suture completion times, no difference was found in the overall quality. Video microsurgery could become a useful tool on the basis of surgeon ergonomics; however, optical parameters require further refinement. (Plast. Reconstr. Surg. 108: 864, 2001.)

90 – Surgical Education Research

Scientific analysis of surgical education is necessary in order to evaluate the existing training methodologies or to introduce new methods and validate them. Studies have uncovered significant problems with current curricula. These include the lack of continuity from undergraduate to graduate surgical training and lack of supervision when acquiring physical examination skills, ultimately resulting in poor performance. The challenges facing healthcare require to rethink all aspects of surgical education. Even though the operating room remains a central part of the training, other teaching arenas will supplement its use. The methods of surgical education are changing rapidly. Bartlett had stated that “there is no simulator for the patient.” However, surgical simulation is now beginning to play a role in surgical residency programs. With increasing computer speed and ongoing bandwidth explosion, web-based education will become commonplace. Scientific evaluation of these new methods is necessary for validation and improvement.

Analysis of motion in laparoscopic instruments

In this study, a system is developed to assess the overall quality of movement, as applied to laparoscopic instruments. A laparoscopic forceps was fitted with a variable inductor as a key component of a Colpitts oscillator. Oscillator frequency is demodulated and digitized into a personal computer equipped with LabView, where trajectories are displayed, analyzed, and stored. In its first study, this system is used to assess velocity in one-dimensional control of instrument insertion depth. Test results indicate that no significant difference in instrument velocity was observed for dominant versus non-dominant hands or for insertion velocity from the first trial to the last. However, extraction of the instrument was seen to occur at significantly higher velocity than insertion, and extraction velocity actually increased over the duration of the trials.

Movement trajectories in laparoscopic tools

In this study, a system was developed to assess quality of movement, as applied to laparoscopic instruments. An instrument is fitted with a variable inductor as part of a Colpitts oscillator. Output frequency is demodulated, sampled, and processed using LabView. In initial studies, this system is used to evaluate velocity and positioning accuracy during insertion and retraction tasks. Data show no significant difference between dominant and non-dominant hands, but velocity for extraction was higher than that of insertion, and marked improvement was seen over a three-day period.