Ramon Berguer

Ergonomic problems associated with laparoscopic surgery.

AbstractBackground: The Society of American Gastrointestinal Endoscopic Surgeons (SAGES) Task Force on Ergonomics conducted a subjective and objective assessment of ergonomic problems associated with laparoscopic instrument use. The goal was to assess the prevalence, causes, and consequences of operational difficulties associated with the use of laparoscopic instruments.n Methods: A questionnaire was distributed asking respondents to rate the frequency with which they experienced pain, stiffness, or numbness in several body areas after laparoscopic operations. An ergonomics station was assembled to quantify forearm and thumb muscle workload. Processed electromyogram (EMG) signals were acquired from 27 volunteer surgeon subjects while they completed simulated surgical tasks using a hemostat and an Ethicon® laparoscopic grasper, with the aid of an endoscopic trainer and video monitoring system.n Results: Of 149 surgeons responding to the questionnaire, 8% to 12% reported frequent pain in the neck and upper extremities associated with laparoscopic surgery. The ergonomics station demonstrated that the peak and total muscle effort of forearm and thumb muscles were significantly greater (p < 0.01) when the grasping task was performed using the laparoscopic instrument rather than the hemostat.n Conclusion: These findings indicate that laparoscopic surgical technique is more taxing on the surgeon.

A comparison of surgeons' posture during laparoscopic and open surgical procedures

AbstractBackground: There is increasing recognition of surgeons physical fatigue in the new ergonomic environment of laparoscopic surgery. The purpose of this study was to determine what the differences are in the movement of the surgeons axial skeleton between laparoscopic and open operations.nnMethods: Surgeons body positions were recorded on videotape during four laparoscopic (LAP) and six open (OP) operations. The percent of time the head and back were in a normal, bent, or twisted position as well as the number of changes in head and back position were tabulated using a computer program. A separate laboratory study was performed on four surgeons ``walking a 0.5-inch polyethylene tubing forward and backward using laparoscopic and open techniques. The movements of the surgeons head, trunk, and pelvis were measured using a three-camera kinematic system (Kin). The center of pressure was recorded using a floor-mounted forceplate (Fp).nnResults: In the operating room surgeons head and back positions were more often straight in laparoscopic procedures and more often bent in open operations. The number of changes in back position per minute were significantly decreased when the laparoscopic-only part of surgery was analyzed. In the laboratory the subjects head position was significantly (p= 0.02) more upright and the anteroposterior (AP) and rotational range of motion of the head was significantly reduced during laparoscopy. Subjects CP was more anterior and there was a significant reduction in the AP range of motion of the CP during laparoscopy.nnConclusions: Our study suggests that surgeons exhibit decreased mobility of the head and back and less anteroposterior weight shifting during laparoscopic manipulations despite a more upright posture. This more restricted posture during laparoscopic surgery may induce fatigue by limiting the natural changes in body posture that occur during open surgery.n

Surgical technology and the ergonomics of laparoscopic instruments

Abstract. Laparoscopic surgery provides patients with less painful surgery and a more rapid recovery, while requiring that surgeons work harder and in a more remote manner from the operating field. Cost-containment pressures on surgeons demand efficient surgery, whereas the increased technological complexity and sometimes poorly adapted equipment have led to increased complaints of surgeon fatigue and discomfort during laparoscopic surgery. There is, therefore, a need to evaluate the ergonomic integration and suitability of the laparoscopic operating room environment to address the issues of efficiency, safety, and comfort for the operating team. This approach is particularly important in the design of laparoscopic surgical instruments. A review of the literature on the biomechanics of laparoscopic surgical instrument use was combined with data from the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Ergonomics Questionnaire and demonstration station. Laparoscopic instruments suffer from ergonomically inadequate handle designs and inefficient handle to tip force transmission, which lead to surgeon fatigue, discomfort, and hand paresthesias. Improvements in the design of laparoscopic instruments are needed to decrease the work and discomfort of tissue manipulation during video-endoscopic surgery.

An ergonomic evaluation of surgeons’ axial skeletal and upper extremity movements during laparoscopic and open surgery

BACKGROUNDnMany surgeons have complained of fatigue and musculoskeletal pain after laparoscopic surgery. We evaluated differences in surgeons axial skeletal and upper extremity movements during laparoscopic and open operations.nnnMETHODSnFive surgeons were videotaped performing 16 operations (8 laparoscopic and 8 open) to record their neck, trunk, shoulder, elbow, and wrist movements during the first hour of surgery. We also compared postprocedural complaints of pain, stiffness, or numbness between the two groups.nnnRESULTSnCompared with surgeons performing open surgery, surgeons performing laparoscopic surgery exhibited less lateral neck flexion; less trunk flexion; more internal rotation of the shoulders; more elbow flexion; more wrist supination and wrist ulnar and radial deviation. There was a trend of more shoulder stiffness after laparoscopic operations than after open operations.nnnCONCLUSIONSnLaparoscopic surgery involves a more static posture of the neck and trunk, but more frequent awkward movements of the upper extremities than open surgery. Ergonomic changes in the operating room environment and instrument design could ease the physical stress imposed on surgeons during laparoscopic operations.

An ergonomic comparison of in-line vs pistol-grip handle configuration in a laparoscopic grasper

AbstractBackground: Laparoscopic instruments incorporate both in-line and pistol-grip handle configurations, yet it is unclear which design is most advantageous for surgeons, particularly when operating at angles perpendicular to the surgeons position. We present a detailed electromyographic (EMG) comparison of these handle configurations under different force and angle conditions.nMethods: Nine general surgeons used a Microsurge grasper with the handle in an in-line (MS-IL) and pistol (MS-PS) configuration, as well as a standard hemostat (HE), to grasp and close two spring-loaded metal plates. The task was performed randomly by each subject with the three instrument configurations at two forces levels (0.7 N, 4.2 N) and at three angles to the surgeons body (0, 45, and 90°). Surface EMG was measured from the flexor carpi ulnaris (FCU), flexor digitorum profundus (FDP), flexor digitorum superficialis (FDS), extensor carpi ulnaris (ECU), extensor digitorum comunis (EDC), and thenar compartment (TH). The peak root mean squared (RMS) EMG voltage was calculated for each instrument, force, and angle condition. Statistical comparison was carried out by ANOVA.nResults: Both laparoscopic handle configurations required significantly higher contractions of all muscle groups compared to the hemostat at the high force level. TH was not affected by laparoscopic handle configuration. MS-IL required higher FCU, ECU, and EDC contractions at 45° compared to MS-PS. However, MS-IL decreased the flexor compartment muscle contractions (FDP, FDS, FCU) at 90° compared to MS-PS.nConclusions: Laparoscopic grasping requires higher forearm and thumb muscle contractions compared to the use of a hemostat. The in-line handle configuration is no better than the pistol configuration except when grasping at 90° to the surgeon, where rotation of the handle and wrist back toward the surgeon significantly decreases forearm flexor compartment muscle contractions.

The effect of laparoscopic instrument working angle on surgeons' upper extremity workload.

BackgroundLaparoscopic surgery may be kinder to the patient, but it is more demanding on the surgeon. Fixed trocar positions often require the surgeon to work with instruments at awkward angles to their body. We studied the effect of horizontal and vertical laparoscopic instrument working angle on the surgeon’s thumb, forearm, and shoulder muscle work.MethodsElectronyographic (EMG) signals were collected from the thenar compartment (TH), flexor digitorum superficialis (FDS), and deltoid (DEL) muscles of the dominant arm of eight surgeons while they were closing a standard pistol-grip disposable laparoscopic grasper against a fixed resistance of 3 N. With the aid of a special testing bench, the instruments’ position was randomly changed among 15°, 45°, and 75° of horizontal angulation relative to the surgeons’ sagital plane, and 15°, 45°, and 75° degrees of vertical angulation relative to a horizontal plane. EMG signals were rectified and smoothed using analogue circuitry and digitally sampled at 10 Hz using a National Instruments DAQCard-700 connected to a Macintosh PowerBook 5300c running LabVIEW software. Statistical analysis was carried out by analysis of variance (ANOVA).ResultsThe effects of vertical and horizontal working angles on the muscle effort were as follows: TH (horizontal, N.S.; vertical, N.S.), FDS (horizontal, p<0.001; vertical, N.S.), and DEL (horizontal, p<0.001; vertical, p<0.01).ConclusionThese results suggest that working with laparoscopic instruments at a horizontal angle of >45° to the surgeon’s sagital plane significantly increases the workload of the flexor digitorium superficialis and deltoid muscles. The deltoid muscle is also adversely affected by vertical angulation of the instrument. The instrument working angle has no effect on the thenar muscles. Whenever possible, laparoscopic surgeons should strive to place their instruments and trocars so as to minimize extreme horizontal or vertical displacement of their hands away from a resting position of comfort.

The relationship between hand size and difficulty using surgical instruments: a survey of 726 laparoscopic surgeons.

Background: Hand size is an important variable to consider when designing hand tools. Laparoscopic surgical instruments have been reported to cause hand and upper extremity discomfort. This study investigates the correlation between surgical glove size, preexisting musculoskeletal problems, and difficulty using laparoscopic instruments. Methods: Approximately 11,000 questionnaires were sent to SAGES, AAGL, and AWS members. Questions included basic demographic and practice data, surgical glove size, the presence of musculoskeletal problems, and the perceived difficulty using several types laparoscopic instruments. There were 726 responses (from 159 women and 567 men). Subjects were grouped by hand size (Small ≤6.5, Medium 7.0–7.5, Large >7.5; female group only: Small ≤6.0, Medium 6.5, Large >6.5). ANOVA was used to test for differences between groups. Results: The percentage of time subjects reported having difficulty using all laparoscopic instruments was greater for the Small glove size group compared to both the Medium and Large groups (p < 0.001). In females, the scissors and staplers were more difficult to use for the Small and Medium glove size group compared to the Large group (p < 0.001). Subjects who reported musculoskeletal problems (n = 145) performed a significantly greater percent of laparoscopic cases and found the stapler and graspers difficult to use for a greater percentage of time than those not reporting problems (n = 559). Conclusion: Hand size is a significant determinant of difficulty using laparoscopic surgical instruments. Individuals using glove sizes 6.5 or smaller experience significantly more difficulty using common laparoscopic instruments, and in particular laparoscopic staplers. Manufacturers of surgical hand tools should consider hand size when designing future surgical instruments.

The optimum pneumoperitoneum pressure for laparoscopic surgery in the rat model. A detailed cardiorespiratory study.

AbstractBackground: There is increasing interest in the rat model of laparoscopic surgery. This study evaluates the cardiorespiratory effects of increasing CO2 pneumoperitoneum (PP) in the rat.nn Methods: Nine Sprague-Dawley rats were subjected to CO2 PP at pressures of 2, 5, 10, and 15 mmHg or control (no PP) under anesthesia. Catheters were placed in the femoral artery and the jugular vein to measure heart rate (HR), blood pressure (MAP), and arterial pH, PCO2, PO2, and HCO3. A thermistor probe in the aortic arch measured cardiac output (CO) and blood temperature (BT).nn Results: CO2 PP had no effect on CO, MAP, or BT at any pressure. CO2 PP greater than 5 mmHg caused significant bradycardia and CO2 PP greater than 10 mmHg caused significant respiratory acidosis.nn Conclusions: CO2 PP pressures above 10 mmHg in rat should be avoided when performing laparoscopic surgery in the rat model.n

Standardized Technique of Laparoscopic Surgery in the Rat

The evolution of advanced laparoscopic techniques requires animal models for instrument development, evaluation of the physiopathological correlation and physician training. Selection of surgical models is primarily based on cost, availability, anatomic and physiologic considerations, and housing and anesthetic methods. The use of large animals is becoming increasingly difficult due to restrictive legislation, public concern, and economic factors. A standardized technique of laparoscopic surgery in the rat has been developed to perform procedures in all abdominal regions including fundoplication, splenectomy, nephrectomy, liver resection, herniorraphy, colotomy, colectomy, and retroperitoneal exploration. The equipment consists of a specially designed small animal operating table, a standard arthroscope and micro-instruments. The rat model gives the opportunity to investigate the physiopathological relations and immune functions of laparoscopic procedures, to develop micro-instruments under realistic conditions of a live organism, and it is an excellent training model especially for pediatric and microsurgery. Besides low costs and easy availability, the rat model requires less logistic and financial efforts.

A comparison of operating room crowding between open and laparoscopic operations

AbstractBackground: The clutter of equipment and lines in todays operating room (O.R.) is increasing. Endoscopic surgical procedures are particularly afflicted by this problem because they require additional equipment. Increasing O.R. crowding may present unnecessary hazards to traffic and adversely affect the performance of the surgical team. The purpose of this study is to provide a quantitative summary of the furniture, equipment, cables, and tubes present during open and laparoscopic operations.nMethods: We prospectively studied an unselected series of general surgical open (OP, n=10) and laparoscopic (LAP, n=10) operations performed at a major university teaching hospital. We recorded the location of all furniture and equipment as well as the source, course, and destination of all cables and tubes in the O.R. Cables and tubes touching the surgeon or the assistant were particularly noted. Results are expressed as median values for each group.nResults: The percent of O.R. space occupied increased from OP=36% to LAP=41% (p<0.002). The median number of cables and tubes present increased from OP=27 to LAP=34 (p<0.0002), with the number of these lines touching a member of the surgical team increasing from OP=2 to LAP=6 (p<0.0003).nConclusions: We conclude that there is a significant trend toward increasing O.R. crowding during laparoscopic surgery. Innovative designs will be needed to reduce clutter in the O.R. of the future.