Ambroise Paré III: Paré’s contributions to surgical instruments and surgical instruments at the time of Ambroise Paré

According to the author, the Oeuvres, edited as early as 1575 from the first opuscules (little works), produced, even at that time, a comprehensive synthesis of the surgical art by assembling not only the experiences and opinions concerning the surgery of his period as a whole but also contributing essential details about the surgical instrumentation of the sixteenth century. Ambroise Paré contributed much to this thanks to his innate sense of the operative art from which he drew largely from experience gained during his military campaigns.     

Determination of the latency effects on surgical performance and the acceptable latency levels in telesurgery using the dV-Trainer® simulator

Background

The primary limitation of telesurgery is the communication latency. Accurate and detailed data are lacking to reveal the latency effects on surgical performance; furthermore, the maximum acceptable latency in telesurgery remains unclear.

Methods

Sixteen medical students performed an energy dissection exercise and a needle-driving exercise on the robotic simulator dV-Trainer^®, and latencies varying between 0 and 1,000 ms with a 100-ms interval were randomly and blindly presented. Task completion time, instrument motion, and errors were automatically recorded. The difficulty, security, precision, and fluidity of manipulation were self-scored by subjects between 0 and 4 (0 the best, 2 moderate, and 4 the worst).

Results

Task completion time, motion, and errors increased gradually as latency increased. An exponential regression was fit to the mean times and motions (R ² > 0.98). Subjective scorings of the four items were similar. The mean scores were less than 1 at delays ≤200 ms, then increased from 1 to 2 at 300–700 ms, and finally approached 3 at delays above. In both exercises, latencies ≤300 ms were judged to be safe by all and 400–500 ms were accepted by 66–75 % of subjects. Less than 20 % of subjects accepted delays ≥800 ms.

Conclusions

The surgical performance deteriorates in an exponential way as the latency increases. The delay impact on instrument manipulation is mild at 0–200 ms, then increases from small to large at 300–700 ms, and finally becomes very large at 800–1,000 ms. Latencies ≤200 ms are ideal for telesurgery; 300 ms is also suitable; 400–500 ms may be acceptable but are already tiring; and 600–700 ms are difficult to deal with and only acceptable for low risk and simple procedures. Surgery is quite difficult at 800–1,000 ms, telementoring would be a better choice in this case.     

Survey of hand surgeons’ and therapists’ perceptions of the benefit of common surgical procedures of the hand

Objective: The objectives of this survey were (1) to study if surgeons’ perceptions of the benefit of six surgical procedures differ if they consider themselves as patients instead of treating a patient, (2) to evaluate the role of five predetermined factors that may influence decision-making, and (3) to assess how uniformly hand surgeons and hand therapists perceive the benefits of the surgical treatments.

Methods: The members of the national societies for Hand Surgery and Hand Therapy were asked to participate in the survey. Six patient cases with hand complaint (carpal tunnel syndrome, flexor tendon injury, dorsal wrist ganglion, thumb amputation, boxer’s fracture, and mallet fracture) and a proposed operative procedure were presented, and the respondents rated the procedures in terms of the expected benefit. Half of the surgeons were advised to consider themselves as patients when filling out the survey.

Results: A survey was completed by 56 surgeons (61%) and 59 therapists (20%). Surgeons who considered themselves as patients had less confident perception on the benefit of carpal tunnel release compared with surgeons, who considered treating patients. Hand surgeons and hand therapists had similar perception of the benefits of surgery. The expected functional result was regarded as the most important factor in directing the decision about the treatment.

Conclusions: Surgeons tended to be more unanimous in their opinions in cases, where there is limited evidence on treatment effect. The agreement between surgeons and therapists implies that the clinical perspectives are similar, and probably reflect the reality well.     

Surgeons’ work ability and performance in surgical care: relations between organisational predictors, work engagement and work ability

Background

The aim of this study was to examine relations and influences between work-related factors, personal resources, work engagement and work ability of surgeons working in German hospitals.

Methods

The study was conducted as a cross-sectional survey investigation. We used the Utrecht Work Engagement Scale, the Copenhagen Psychosocial Questionnaire and the Work Ability Index to evaluate surgeons’ work engagement, working conditions and work ability. Bivariate analyses and a stepwise regression analysis were performed.

Results

Surgeons reported a moderate work ability and work engagement. The results indicated significant associations between surgeons’ sources of work engagement, work ability and work-related factors (e.g. job resources). Significant differences regarding these variables were also detected between males and females and the various age groups.

Conclusion

The study results reflect the positive effect of supportive working conditions and work engagement on the preservation of work ability, indicating their importance in promoting surgeons’ work ability. Due to the elderly population and the continuing development of health care in Germany, the demand for surgeons increases. These circumstances give reasons for a strong need to preserve and restore surgeons’ work ability. New strategies for training and improving the capacity and performance of surgeons are necessary.     

How are clinical outcomes related to the deviation severity of the tibiofemoral mechanical axis on coronal plane following knee arthroplasty?

ObjectiveTo analyze the effect of tibiofemoral mechanical axis (TFMA) deviation severity on clinical outcomes after total knee arthroplasty (TKA).MethodsWe retrospectively reviewed the patients who underwent primary TKA between January 2002 and December 2010. After applying inclusion/exclusion criteria, we evaluated 70 knees of 51 patients. The mean ± SD follow-up period was 7.08 ± 1.34 years. The knees were divided into 3 groups based on TFMAs. The first group, identified as “well aligned,” included the TFMAs that were neutral within 3° (0° ± 3°) of alignment. The second group, identified as “outliers 1,” included the slightly deviated TFMAs (−3° to −6° valgus and +3° to +6° varus). The third group, identified as “outliers 2,” included the severely deviated TFMAs of more than 6° from neutral alignment (<−6° valgus and > + 6° varus). The clinical outcomes of each group were compared by evaluating the Oxford Knee Score (OKS), visual analog scale (VAS), and Short Form-36 physical component summary (SF-36 PCS) and mental component summary (SF-36 MCS) scores.ResultsWe found that OKS, SF-36 PCS, and SF-36 MCS were nearly the same in the well-aligned and outliers 1 groups but worse in the outliers 2 group. VAS scores were nearly the same in all groups. (p > 0.05)ConclusionFunction scores were impaired when the TFMA deviated more than 6° from neutral. However, the differences in clinical outcomes between well-aligned knees and those of outliers were not found to be statistically significant in the medium term.     

Effect of the Daguerreotype Process on Morton’s Part in History

Because daguerreotype photographs are usually reversed laterally from actuality, images of W.T.G. Morton falsely suggest that he sometimes changed the side of the part in his hair. Because of daguerreotype image reversal, a statue of Apollo in the Ether Dome at the Massachusetts General Hospital appears to have been moved for the 50th anniversary of Ether Day.     

Effect of Exercise on Learning,Memory and Levels of Epinephrine in Rats’ Hippocampus

The aim of the present study was to investigate effect of exercise on learning and memory, long-term potentiation and levels of epinephrine in the rat hippocampus. Treadmill trained (one hour at 17 m·min^-1 for 10 days) and corresponding control rats went through spatial learning process on a Morris water maze for 8 days. The time to reach the platform (latency), the length of swim path, and the swim speed were used for the evaluation of spatial learning. Our results showed that physical activity produced a significant enhancement in spatial learning, with a decreased path length (p<0.05) and latency (p<0.05) to the platform in Morris water maze, without affecting the swim speed. Furthermore, the levels of the epinephrine were significantly increased (p<0.05) in hippocampus of the exercised rats. In conclusion our findings suggest that the enhanced learning by exercise may be mediated through the activation of adrenoceptors in the hippocampus and epinephrine may play an important role in potentiation of learning.Key Words: Exercise, memory, hippocampus, epinephrine     

The relationship between Parson’s tubercle and the insertion of the anterior horn of the medial meniscus

Purpose: The purpose of this investigation was to correlate the anatomic characteristics of the third intercondylar tubercle of Parsons (TITP) with the insertional variations of the anterior horn of the medial meniscus using precise measurements in an anatomic cadaver study. Our hypothesis was that the height of the TITP would correlate with the degree of inferior insertion of the medial meniscus. Type of Study: A cadaver study using a convenience sample. Methods: Twenty unpaired proximal tibia specimens without advanced arthritis were analyzed with a coordinate measuring machine using a 0.479-mm diameter probe. A reference plane was created using 3 reproducible points on the tibial surface. Measurements from the TITP included another reference plane through its base, which was used to calculate its absolute height. The locations of the anterior- and inferior-most insertional points of the anterior horn of the medial meniscus were also determined. Correlations between the height of the TITP and age were also made. Results: The overall height of the TITP was found to correlate with the degree of inferior insertion of the anterior horn of the medial meniscus (r = .52, P = .019). No correlation was found with the anterior placement of the meniscus (r = .12, P = .629) or with the age of the specimen (r = .14, P = .592). Conclusions: This absolute height of the TITP correlates with the inferior location of the insertion of the anterior horn of the medial meniscus. This association suggests a developmental relationship between 2 anatomic structures within the knee.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 7 (September), 2001: pp 737–740     

Impact of examinees’ stereopsis and near visual acuity on laparoscopic virtual reality performance

Purpose

Laparoscopic surgery represents specific challenges, such as the reduction of a three-dimensional anatomic environment to two dimensions. The aim of this study was to investigate the impact of the loss of the third dimension on laparoscopic virtual reality (VR) performance.

Methods

We compared a group of examinees with impaired stereopsis (group 1, n = 28) to a group with accurate stereopsis (group 2, n = 29). The primary outcome was the difference between the mean total score (MTS) of all tasks taken together and the performance in task 3 (eye–hand coordination), which was a priori considered to be the most dependent on intact stereopsis.

Results

The MTS and performance in task 3 tended to be slightly, but not significantly, better in group 2 than in group 1 [MTS: ?0.12 (95 % CI ?0.32, 0.08; p = 0.234); task 3: ?0.09 (95 % CI ?0.29, 0.11; p = 0.385)]. The difference of MTS between simulated impaired stereopsis between group 2 (by attaching an eye patch on the adominant eye in the 2nd run) and the first run of group 1 was not significant (MTS: p = 0.981; task 3: p = 0.527).

Conclusion

We were unable to demonstrate an impact of impaired examinees’ stereopsis on laparoscopic VR performance. Individuals with accurate stereopsis seem to be able to compensate for the loss of the third dimension in laparoscopic VR simulations.

     

Does the subjective evaluation of medical student surgical knowledge correlate with written and oral exam performance?

BACKGROUND: Medical student performance evaluations have historically contained a significant subjective component. Multiple tools are used to assess fund of knowledge including subjective evaluation by faculty and residents as well as objective evaluations through standardized written and oral exams. We hypothesized that subjective evaluation of medical student knowledge would correlate with objective evaluation through written and oral exams. METHODS: Records of consecutive medical students assigned to the surgery clerkship from January 1999 and March 2001 were reviewed. The core surgical rotation consisted of two 4-week blocks on a private, county, or VA hospital service. Surgical knowledge was assessed subjectively by both faculty (FES) and senior residents (RES) using a 10-point scale with verbal anchors. Objective measures of student surgical knowledge included the National Board shelf exam (WE) and a semistructured oral exam (OE). Data are reported as mean +/- SEM. Spearman rank correlation coefficient (r) was used to assess relationships between groups (r > or = 0.5 --> positive correlation). RESULTS: A total of 354 students were evaluated. The mean FES was 7.8 +/- 0.05 (median = 7.75, range 4.75 to 9.75). The mean RES was 7.7 +/- 0.06 (median = 8.0, range 3.5 to 10.0). There was poor correlation between the subjective perception and objective measures of surgical knowledge (Table 1). Comparison of the FES and RES also showed poor correlation (r = 0.38). CONCLUSIONS: Subjective evaluation of surgical knowledge by faculty and residents correlates poorly with performance measured objectively. These results question whether subjective evaluation of surgical knowledge should be included as part of the evaluation process.     

Comparison of the sensitivity of physical and virtual laparoscopic surgical training simulators to the user’s level of experience

Background: The recent focus on quality of care and patient safety has been accompanied by increased interest in standardizing the training for laparoscopic surgeons. Studies have shown that laparoscopic simulators can be used to train surgical skills. Therefore, we designed an experiment to compare the effectiveness of two popular training systems. One system was based on a physical model, whereas the other used a virtual reality model. Methods: A total of 32 medical students and residents were tested on both simulators. Time required for task completion and number of errors committed were recorded and compared. Results: The physical training system differentiated among experience levels on three of the five tasks when time was used as a measure and four of five tasks when score was used, whereas the virtual reality system yielded statistically significant results in eight of 13 tasks for time and in five of 13 tasks for score. Conclusion: The physical model is more sensitive than the virtual reality one in detecting differences in levels of laparoscopic surgical experience.     

Impact of surgical training and surgeon’s experience on early outcome in kidney transplantation

Purpose

The purpose of this study was to assess the impact of surgical training and surgeon’s experience on surgical quality and early outcome parameters.

Methods

The outcomes of 184 deceased donor kidney transplant procedures were retrospectively reviewed. Intraoperative quality parameters, complication rates, and early outcome parameters were analyzed with respect to surgeon’s experience. Surgeons were grouped according to their level of experience: trainees (n?=?5), who were senior residents in their transplant rotation; low-experience surgeons (n?=?4), who had an individual caseload of at least 30 supervised procedures; medium-experience surgeons (n?=?5), who had an individual caseload of a minimum of 30 unsupervised (+30 supervised) procedures; and high-experience surgeons (n?=?2), who had an individual caseload of more than 200 procedures.

Results

Surgical training was offered in 20 % of all cases. Surgeons with a high experience in kidney transplantation had a significantly lower warm ischemic time (30 versus 35 min, p?=?0.01) and total operation time (135 versus 155 min, p?=?0.43) as compared to the other study groups. However, this did not translate into a better outcome after transplantation. The complication rate and early outcome parameters such as length of hospital stay, serum creatinine at discharge, and graft and patient survival at 3 months post TX did not show any significant difference between the groups.

Conclusion

We conclude that hands-on training of residents in kidney transplantation is feasible and surgical experience can be safely gained within a staged surgical training program.     

The Protective Effect of Aprotinin and α-Tocopherol on Ischemia-Reperfusion Injury of the Rat Liver

Background

Liver injury caused by ischemia-reperfusion (I/R) processes is a complication of hepatic resection surgery and transplantation, particularly using grafts from marginal donors. Despite improvements in organ preservation and advances in surgical techniques, I/R injury remains a significant clinical problem. In this study, we investigated whether aprotinin provided protection against the adverse effects of I/R injury in liver tissue.

Methods

Forty rats were randomized into four groups (n = 10): group I: (control group) I/R + no medication; group II: sham-operated group + no medication or I/R; group III: I/R + aprotinin; group IV: I/R + α-tocopherol. Malondialdehyde (MDA) was measured in the liver tissue and superoxide dismutase (SOD), catalase (CAT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), as well as lactate dehydrogenase (LDH) in rat serum.

Results

Administration of aprotinin and α-tocopherol before I/R resulted in significant reductions of MDA levels compared to the I/R alone group (group I; P = .01 and P < .01, respectively). Administration of aprotinin or α-tocopherol prior to I/R resulted in significant increases in SOD and CAT levels compared with the I/R group (P < .05 each). Compared to the I/R group, significant decreases in plasma AST, ALT, and LDH levels were observed both in the aprotinin and in the α-tocopherol group (P < .05). Histological evaluation revealed the injury grade to be relatively lower among groups III and IV compared to group I.

Discussion

In conclusion, rat hepatic structures in aprotinin and α-tocopherol administered groups were well protected. Therefore, aprotinin may provide protection against the adverse effects of I/R injury in liver transplantation.     

Comparative assessment of surgeons’ task performance and surgical ergonomics associated with conventional and modified flank positions: a simulation study

Background

Flank position is extensively used in retroperitoneoscopic urological practice. Most surgeons follow the patients’ position in open approaches. However, surgical ergonomics of the conventional position in the retroperitoneoscopic surgery is poor. We introduce a modified position and evaluated task performance and surgical ergonomics of both positions with simulated surgical tasks.

Methods

Twenty-one novice surgeons were recruited to perform four tasks: bead transfer, ring transfer, continuous suturing, and cutting a circle. The conventional position was simulated by setting an endo-surgical simulator parallel to the long axis of a surgical desk. The modified position was simulated by rotating the simulator 30° with respect to the long axis of the desk. The outcome measurements include task performance measures, kinematic measures for body alignment, surface electromyography, relative loading between feet, and subjective ratings of fatigue.

Results

We observed significant improvements in both task performance and surgical ergonomics parameters under the modified position. For all four tasks, subjects finished tasks faster with higher accuracy (p < 0.005 or < 0.001). For ergonomics part: (1) The angle between the upper body and the head was decreased by 7.4 ± 1.7°; (2) The EMG amplitude collected from shoulders and left lumber was significantly lower (p < 0.05); (3) Relative loading between feet was more balanced (p < 0.001); (4) Manual-action muscles and postural muscles are rated less fatiguing according to the questionnaire (p < 0.05).

Conclusions

Conventional position of patient in retroperitoneoscopic upper urinary tract surgery is associated with poor surgical ergonomics. With a simulated surgery, we demonstrated that our modified position could significantly improve task performance and surgical ergonomics. Further studies are still warranted to validate these benefits for both patients and surgeons.     

A comparison of surgical outcomes between endoscopic and robotically assisted thyroidectomy: the authors�� initial experience

Background  

The gasless, transaxillary endoscopic thyroidectomy (GTET) offers a distinct advantage over the conventional open operation by leaving no visible neck scar, and in an attempt to improve its ergonomics and surgical outcomes, the robotically assisted thyroidectomy (RAT) was introduced. The RAT uses the same endoscopic route as the GTET but with the assistance of the da Vinci S robotic system. Excellent results for RAT have been reported, but it remains unclear whether RAT offers any potential benefits over GTET.