Peroperative time-motion analysis of diagnostic laparoscopy with laparoscopic ultrasonography

The influence of prolonged instrument manipulation on gas leakage through trocars

BACKGROUND

During laparoscopic surgery, CO2 insufflation gas could leak from the intra-abdominal cavity into the operating theater. Medical staff could therefore be exposed to hazardous substances present in leaked gas. Although previous studies have shown that leakage through trocars is a contributing factor, trocar performance over longer periods remains unclear. This study investigates the influence of prolonged instrument manipulation on gas leakage through trocars.

METHODS

Twenty-five trocars with diameters ranging from 10 to 15 mm were included in the study. An experimental model was developed to facilitate instrument manipulation in a trocar under loading. The trocar was mounted to a custom airtight container insufflated with CO2 to a pressure of 15 mmHg, similar to clinical practice. A linear stage was used for prolonged instrument manipulation. At the same time, a fixed load was applied radially to the trocar cannula to mimic the reaction force of the abdominal wall. Gas leakage was measured before, after, and during instrument manipulation.

RESULTS

After instrument manipulation, leakage rates per trocar varied between 0.0 and 5.58 L/min. No large differences were found between leakage rates before and after prolonged manipulation in static and dynamic measurements. However, the prolonged instrument manipulation did cause visible damage to two trocars and revealed unintended leakage pathways in others that can be related to production flaws.

CONCLUSION

Prolonged instrument manipulation did not increase gas leakage rates through trocars, despite damage to some individual trocars. Nevertheless, gas leakage through trocars occurs and is caused by different trocar-specific mechanisms and design issues.

Learning Curve of a Minimally Invasive Technique for Transcrestal Sinus Floor Elevation: A Split-Group Analysis in a Prospective Case Series With Multiple Clinicians

AIMS

To assess the learning curve of a minimally invasive procedure for maxillary sinus floor elevation with a transcrestal approach (tSFE) and evaluate the influence of clinician's experience in implant surgery on its outcomes.

MATERIALS AND METHODS

Patients were treated by clinicians with different levels of experience in implant surgery and inexperienced with respect to the investigated tSFE technique. The initial (n = 13) and final (n = 13) groups treated by the expert clinician were compared for tSFE outcomes. Additionally, the high, moderate, and low groups (n = 20 each) treated by the expert, moderately experienced, and low experienced clinician, respectively, were compared.

RESULTS

(1) No significant differences in clinical and radiographic outcomes were observed between initial and final groups; (2) high, moderate, and low groups showed substantial vertical augmentation in limited operation time with treatment outcomes being influenced by the level of experience in implant surgery.

CONCLUSIONS

The investigated technique allows for a substantial vertical augmentation at limited operation times when used by different clinicians. The extent of sinus lift (as radiographically assessed) seems to be influenced by the clinician's level of experience in implant dentistry.

Time and motion in cosmetic surgery

Time and motion studies have been used to analyze performance and improve outcomes. This prospective study evaluated a typical operating day at a surgical facility in the United Kingdom by recording admitting time into the hospital, entrance and exit times from theatre, and length of surgical time. The same surgical team performed 10 breast augmentations in less than 10 hr, with a mean preparation time of 9 min 20 s and a mean surgical time (from incision to closure) of 32 min. The mean exit time was 6 min 15 s, with a mean changing time between patients of about 24 min (median = 21 min). No adverse patient complications were reported.

Assessment of ergonomics in laparoscopic surgery

At Delft University designers are educated to design 'products for people'. Therefore the field of ergonomics has been divided along the human functions: physical, sensorial and cognitive ergonomics. This article gives an overview of the assessment of these aspects of ergonomics in laparoscopic surgery. It is concluded that a systematic approach is needed, in which knowledge that has already been accumulated for different workplaces (for example, in industry) is applied to the surgeon's circumstances. Such an approach would lead to a set of objectively testable ergonomic requirements for all kinds of products that are used by surgeons in the operating room.

Time-action analysis of laparoscopic procedures - input for clinically driven instrument design

Clinically driven instrument development aims at reducing clinically important problems of the surgical process. The input for clinically driven instrument design originates in the difficulties that occur during the peroperative process. This paper describes a method of time–action analysis as a tool to provide input for designers. Four steps can be distinguished in the process of clinically driven instrument development: (1) assessment of the instrument-related difficulties during operations; (2) the translation of the clinical problems into technical design specifications; (3) the construction of a prototype; (4) the evaluation of the prototype. Time–action analysis can be used to detect the difficulties of the operative process in detail, supporting Step 1 of the clinically driven development process. In addition, it can be used to evaluate objectively the efficiency and limiting factors of new prototypes in comparison to currently available instruments (Step 4).

Simulation and surgical training

The aim of this review was to outline current forms of surgical simulation and methods of assessing technical skills using these forms of simulation. To review this subject, a literature search was done using key words 'assessment', 'simulation', 'surgery', 'technical skills' and 'virtual reality'. Simulation in surgery has several forms, inorganic (synthetic & computer) and organic (animal or cadaver). Surgical simulation is a mode of training which is promising and may be effective. Technical errors in the simulated environment do not have clinical consequences and does not have a morbidity or mortality. We must ensure that the competent skills learnt in the simulation environment are translated to the real environment. This can be achieved if the same assessment tools are used in both environments. Surgical training is entering a new era, with increased scrutiny and an evolving work and training environment. We as surgical teachers must ensure that the surgeons of the future are as competent as or better than their predecessors using these new modes of training which we have access to.

Disturbances in the arthroscopic view defined with video analysis

Optimization of arthroscopic view with technological innovation. To formulate objective measures for arthroscopic image quality. This is achieved by defining uniquely interpretable descriptions of disturbances of the arthroscopic image. Disturbances in the arthroscopic view were defined focusing on the size of the disturbance area, and the duration of a disturbance. They were categorized as Bleeding, Turbidity, Air Bubbles, Loose Fibrous Tissue, Attached Fibrous Tissue, Tissue too Close, and Instrument too Close. Ten arthroscopic knee procedures were recorded on digital film with a frame rate of 25 images per second (almost 5 h in total). Using time-action analysis, two investigators individually scored the presence and type of each disturbance in all 5 h of the ten arthroscopies. The kappa statistic was used to assess agreement between the investigators. Additionally, five other observers, who had no prior training, scored 1 min of each of the ten arthroscopies (total of 10 min) to evaluate the definitions for unique interpretability. The adjusted kappa statistic (kappa is corrected for high prevalence) shows good tester agreement for all disturbances (range 0.71-0.96), also for the observers who had no prior training. Only Turbidity shows a moderate agreement (0.59 and 0.44). This is due to the difficulty to assess the exact start and end time of Turbidity. We succeeded in describing uniquely interpretable definitions for seven disturbances. This allows objective and quantitative determination of arthroscopic image quality, which is required to improve future arthroscopic equipment and training facilities.

[Tumor volume in advanced gastric cancer as a prognostic factor correlating with lymph node involvement]

INTRODUCTION

It has been established that measurement of tumor volume, rather than its diameter, is a better indicator of the depth of tumor invasion and lymph node involvement. The present study evaluates the significance of tumor volume as a prognostic factor in gastric cancer.

MATERIAL AND METHODS

This prospective clinical trail included 87 patients with gastric cacncer admitted to Surgery Clinic "Dr. Dragisa Misović" in Belgrade from 1998 to 2003. All patients were evaluated by standard diagnostic procedures, and after that underwent radical surgical treatment. Oncologic-surgical principles recommended by Japanese Research Society for Gastric Cancer were respected. Tumor volume was determined by measurement of specimens that had been obtained during surgery and by histopathological analysis. These criteria were analyzed and correlated with the lymph node status and clinicopathological factors.

RESULTS

Single-factor analysis showed that lymph node metastases correlated with larger tumor diameter, larger tumor volume, depth of tumor invasion, diffuse and low-grade differentiation of the intestinal type of gastric carcinoma. Using a linear correlation coefficient, it was found that there was a highly significant correlation of tumor volume and number of metastatic nodes in groups between lymph nodes r = 0.567; p < 0.0001 in drainage group 1, r = 0.511; p < 0.0001 in drainage group II, r = 0.579; p < 0.0001 in drainage group III. Also, there was highly significant correlation with the total number of metastatic nodes (r = 0.577; p < 0.0001) and significant correlation with the depth of tumor invasion and tumor diameter (p < 0.05). With 97% sensitivity and 88% specificity, "cut off" point was established by determining the tumor volume above which there were metastases into lymph nodes. In this study that volume was 2750 cmm.

CONCLUSION

Tumor volume can be used as a valuable prognostic factor for advanced gastric cancer, and hopefully it will be calculated preoperatively by 3D-EUS volumetric analysis.

Identifying error pathways during elbow and knee replacements

The aim of our study was to identify errors and error pathways during joint replacements and to propose improvements. A time-action and error analysis method was adapted for use during surgery. The error analysis consisted of identifying all possible errors, determining error paths presented in an error chart, quantifying errors, and determining the impact of errors. This method was used to evaluate joint replacements. We evaluated five knee and 11 elbow replacements done by two experienced surgeons. The main error for elbow replacements was caused by inadequate instruments. The main error for knee replacements was caused by inexperienced nurses being unfamiliar with guiding instruments. The time-action analysis showed a large variation in procedure duration. The main surgical limitations for both procedures were waiting caused by the cementing process and waiting caused by inexperienced scrub nurses. Our study identified errors and surgical limitations during joint replacements by using time-action and error analysis. Placement of both prostheses will benefit from new fixation techniques, a more experienced nursing staff, and more organized instrument tables.

The impact of sleep deprivation on product quality and procedure effectiveness in a laparoscopic physical simulator: a randomized controlled trial

BACKGROUND

To compare the impact of sleep deprivation after 24-hour duty (post-call) with that of 8-hour work (post-work) on product quality (PQ) and procedure effectiveness (PE) in a laparoscopic physical simulator.

METHODS

Voluntary surgeons and nurses were pretested with the Epworth Sleepiness Scale (ESS) and Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR). Surgical task was suturing perforated ulcer on a foam stomach in a physical simulator. PQ and PE were measured by accuracy error (AE), tissue damage (TD) leak rate (LR), goal- (GDA) non-goal-directed actions (NGDA), and operating time (OT), respectively. Construct validity was assessed comparing measures when surgeons and nurses performed the surgical task. Inter-rater reliability (IRR) was assessed by Kendall's tau b coefficient. An 80% power parallel block randomization design at alpha = .05 required 60 subjects.

RESULTS

Thirty-two post-call surgeons and 32 post-work surgeons were well matched for age, gender, practice duration, and ESS and MIST-VR scores. The amount of time slept in the previous 24 hours was 1.5 versus 6.5 hours (P < .05). AE (1.0 mm vs. .5 mm), TD (2.18 mm vs. 2.18 mm), LR (56.2% vs. 65.6%), GDA (33.5 vs. 32.5), NGDA (.56 vs. .31), and OT (381.0 seconds vs. 364.5 seconds) were not significantly different when 32 surgeons in the post-call arm were compared with their 32 counterparts in the post-work arm, respectively. Construct validity was shown by significant improvement in 4 outcome measures (AE 1.0 mm vs. 2.0 mm, P = .00001; GDA 32.5 vs. 39.0, P = .07, NGDA .43 vs. .96, P = .045; and OT 377.5 vs. 557.0, P = .0005) when 64 surgeons performed the task as compared to 64 nurses. Tau b for IRR was 1.0 (P < .0001) for AE, TD, LR, and OT, .75 (P = .325) for GDA, and .77 (P = .305) for NGDA.

CONCLUSIONS

Sleep deprivation had no impact on the studied outcome measures of a surgical task performed in a laparoscopic simulator.

Randomized study of the effectiveness of closing laparoscopic trocar wounds with octylcyanoacrylate, adhesive papertape or poliglecaprone

BACKGROUND

Several methods for skin closure are used, i.e. sutures, adhesive papertape and tissue adhesives. Little is known about the efficacy of these techniques in laparoscopic surgery. This study was performed to analyse the efficacy of octylcyanoacrylate, a new tissue adhesive, adhesive papertape and poliglecaprone for wound closure in laparoscopy.

METHODS

From May 2000 to September 2001, 140 patients were included in a prospective randomized trial. Wounds were closed with octylcyanoacrylate (n = 48), adhesive papertape (n = 42) or poliglecaprone (n = 50). Closing time, wound infection, cosmetic results and costs were evaluated. A time-motion analysis was also performed.

RESULTS

The patients in the three groups were well matched for age, gender and body mass index. Closing times per wound were 26, 33 and 65 s respectively for adhesive papertape, octylcyanoacrylate and poliglecaprone (P < 0.001). Cosmetic results, as scored by the patients, were no different. The number of actions required to close each wound was 5.7, 8.3 and 21.0 for octylcyanoacrylate, adhesive papertape (P = 0.05 versus octylcyanoacrylate) and poliglecaprone (P < 0.01 versus octylcyanoacrylate and adhesive papertape) respectively. Octylcyanoacrylate was significantly more expensive than poliglecaprone and adhesive papertape.

CONCLUSION

Closure with adhesive papertape was the fastest method. The smallest number of actions required to close a wound was with octylcyanoacrylate. Adhesive papertape was the most cost-effective.

Evaluation of vascular and interventional procedures with time-action analysis: a pilot study

PURPOSE

To provide an objective method to measure the efficiency of vascular and interventional procedures.

MATERIALS AND METHODS

The time-action analysis method is defined for peripheral vascular and interventional procedures. A taxonomy of actions is defined, geared specifically toward these procedures. The actions are: start-up/wrap-up, exchange, navigate, image, diagnose, treat, handle material, wait, compress puncture site, and unclassified. The recording method and analysis techniques are described. To show the type of data that can be obtained, the time-action analysis of 30 procedures is presented.

RESULTS

The results provide a detailed picture of the time spent on various actions. Of all actions, the most time is spent on compressing the puncture site (18.5%), whereas the highest frequency of actions are for exchange of catheters, guide wires, and sheaths (20.4 times per procedure). Radiation exposure can be analyzed in detail, which can yield directions for possible reduction. For instance, 5.2%-8.3% of the total radiation exposure occurs during preparation of imaging to adjust the position of the patient table and set the image intensifier diaphragm.

CONCLUSION

Time-action analysis provides an objective measurement method to monitor and evaluate vascular and interventional procedures. Potential applications and limitations of the technique are discussed.

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.

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.

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.