Surgical Endoscopy

, Volume 30, Issue 3, pp 1205–1211 | Cite as

Impact of single-incision laparoscopic cholecystectomy (SILC) versus conventional laparoscopic cholecystectomy (CLC) procedures on surgeon stress and workload: a randomized controlled trial

  • Amro M. Abdelrahman
  • Juliane Bingener
  • Denny Yu
  • Bethany R. Lowndes
  • Amani Mohamed
  • Andrea L. McConico
  • M. Susan HallbeckEmail author
Open Access



Single-incision laparoscopic cholecystectomy (SILC) may lead to higher patient satisfaction; however, SILC may expose the surgeon to increased workload. The goal of this study was to compare surgeon stress and workload between SILC and conventional laparoscopic cholecystectomy (CLC).


During a double-blind randomized controlled trial comparing patient outcomes for SILC versus CLC (NCT0148943), surgeon workload was assessed by four measures: surgery task load index questionnaire (Surg-TLX), maximum heart rate, salivary cortisol level, and instruments usability survey. The maximum heart rate and salivary cortisol levels were sampled from the surgeon before the random assignment of the surgical procedure, intraoperatively after the cystic duct was clipped, and at skin closure. After each procedure, the surgeon completed the Surg-TLX and an instrument usability survey. Student’s t tests, Wilcoxon rank sum test, and Kruskal–Wallis nonparametric ANOVAs on the dependent variables by the technique (SILC vs. CLC) were performed with α = 0.05.


Twenty-three SILC and 25 CLC procedures were included in the intent-to-treat analysis. No significant differences were observed between SILC and CLC for patient demographics and procedure duration. SILC had significantly higher post-surgery surgeon maximum heart rates than CLC (p < 0.05). SILC also had significantly higher mean change in the maximum heart rate between during and post-procedure (p < 0.05) than CLC. Salivary cortisol level was significantly higher during SILC than CLC (p < 0.01). Awkward manipulation of the instruments and limited fine motions were reported significantly more frequently with SILC than CLC (p < 0.01). In the surgeon-reported Surg-TLX, subscale of physical demand was significantly more demanding for SILC than CLC (p < 0.05).


Surgeon heart rate, salivary cortisol level, instrument usability, and Surg-TLX ratings indicate that SILC is significantly more stressful and physically demanding than the CLC. Surgeon stress and workload may impact patients’ outcomes; thus, ergonomic improvement on SILC is necessary.


Surgeon Laparoscopy SILC Workload Surg-TLX Stress 

Single-incision laparoscopic cholecystectomy (SILC) is a novel minimally invasive procedure to cholecystectomy and appears to have a similar safety profile as conventional laparoscopic cholecystectomy (CLC) [1, 2, 3]. Although patients prefer the cosmetic outcome of SILC over CLC [4], SILC procedure presents significant technical and workload challenges for surgeons [5]. By placing all the instruments through one incision, the single-incision procedure reduces the instruments’ range of motion, increases the collisions between the instruments, and decreases the optics and instruments’ degree of freedom [6]. These technical challenges could increase the surgeon workload related to the SILC. This high physical workload can increase the surgeons’ musculoskeletal injury risk [7, 8, 9]. Studies in a simulation setting have shown a significant decrease in task performance using SILC compared to CLC; this effect was consistent across all expertise levels [10] and with different SILC instrumentations [11]. In summary, SILC may adversely affect the surgeon’s health and performance, which may also lead to a compromise of safety for patients’ health and the health care delivery system [12, 13].

Although SILC has been compared frequently to CLC based upon patients’ primary and secondary outcomes [14], the impact of the single-port technique on surgeon workload is not yet fully understood. Limited studies have systematically measured surgeons’ operative stress and workload and compared stresses between SILC and CLC. Ergonomic studies are needed to quantify the surgeon stress and workload to identify ergonomic risk factors that may impact surgeons’ health and their career longevity [15]. The goal of this study was to compare surgeon stress and workload during a randomized controlled study for SILC and CLC in the operating room.

Materials and methods

To evaluate differences in surgeon workload between SILC and CLC procedures, objective and subjective workload data were collected alongside a double-blind randomized controlled trial (RCT) comparing patient outcomes between SILC and CLC. All procedures were completed by one surgeon (NCT0148943).


Potential patients were identified from the clinical practice according to inclusion (electing cholecystectomy for symptomatic gallstone disease) and exclusion criteria for this randomized controlled trial (RCT) NCT0148943. Patients less than 18 years of age, pregnant women or prisoners/institutionalized individuals were excluded from the trial as were patients with American Society of Anesthesiology (ASA) class >3, those undergoing chronic treatment with opiates, biopsy-proven gallbladder cancer, or patients unable or unwilling to provide consent for the study. Enrolled patients were scheduled as early case of the day. Randomization occurred after anesthesia induction by computer-generated randomization stratified by age, gender, body mass index (BMI), and insulin-dependent diabetes mellitus. Patients remained blinded to the surgical procedure for 48 h postoperatively, using four identical occlusive dressings.

Surgeon workload data were collected for 48 cases. Patient factors, i.e., BMI, age, and gender, among cases were stratified and controlled as part of the RCT. Both SILC and CLC techniques were used to perform laparoscopic cholecystectomy. For SILC patients, one umbilical skin incision was used and performed manually using a TriPortTM trocar (WA58000T, Olympus, Inc.) by the surgeon. For the patients who underwent CLC procedures, three 5-mm ports and one 12-mm port (Hasson trocar) were located on the abdominal wall.

Evaluation of surgeon workload

Surgeon stress and workload were quantified at three distinct time points during each case: pre-, intra-, and postoperatively. Preoperative time was defined as before randomization into CLC or SILC. Intraoperative time was defined as the time the cystic artery and duct were clipped. Finally, postoperative time was defined as time of skin closure.

Workload was measured using the surgery task load index (Surg-TLX) and instrument usability survey. The Surg-TLX was adapted from National Aeronautics and Space Administration’s Task Load Index (NASA-TLX) [16, 17] and was validated for distinguishing workloads in surgery [18]. In the Surg-TLX, surgeons rated six dimensions of workload, i.e., mental, physical, temporal, task complexity, situational awareness, and distractions, on visual analogue scales (VAS) where zero is “very low” and 20 is “very high.”

The instruments usability survey was adapted from Trejo et al. [19] and Beurskens et al.’s [20] work. The surgeon participant rated laparoscopic instrument usability (e.g., awkwardness and inability to perform precise motions) in three-point scale as “None,” “Slight,” and “Substantial.” Instrument usability was assessed after each procedure. For the analysis, these outcomes were categorized binomially as present (i.e., substantial and slight) or absent (i.e., none).

Surgeon heart rate was collected at the pre-, intra-, and postoperative time points. Surgeon heart rate was collected using a portable and wireless BodyGuardian Remote Monitoring System™ by Preventice®. Heart rate data were collected continuously throughout the procedure and sampled for 5 min (2.5 min on each side) of the three previously defined time points.

Surgeon stress hormone (i.e., salivary cortisol) levels were sampled at each time point (i.e., pre-, intra-, and postoperative) with the saliva collection aid (Salimetrics, part number 5016.02). Saliva samples were placed in dry ice immediately after sampling, and all samples were frozen (−80 °C) after the procedure. At the conclusion of the study, salivary samples from all cases were thawed, centrifuged at 3000 rpm, and the salivary cortisol batch was assayed using ELISA [21-3002].

Data analysis

Patient characteristics, operative time, and workload were compared between SILC and CLC using the Statistical Analysis System (SAS® version 9.3; SAS Institute Inc., Cary, NC), and intention-to-treat analysis was performed. Fisher’s exact test and equal variance t tests were used to address assumptions in variable characteristics, variance distribution, and sample size and compare differences in patients’ age, gender, and BMI. Differences in operative duration (defined as skin-to-skin time) between SILC and CLC were tested using equal variance t tests.

Data were categorized by time point during the surgery (i.e., pre-, intra-, and postoperatively). At the pre-, intra-, and postoperative time points, maximum heart rate (based on sample of 2.5 min around the time point) and salivary cortisol levels during SILC and CLC procedures were compared using Wilcoxon rank sum and t tests, as appropriate. To overcome the diurnal rhythm changes in the cortisol level, treatment-received analysis was also performed for the first cases of the day only between the SILC and CLC. In addition, differences in heart rate and cortisol levels were calculated between paired time points (e.g., pre- minus postoperative heart rate and pre- minus intraoperative heart rate) and were compared between SILC and CLC using Wilcoxon rank sum test, ANOVAs, and unequal/equal variance t tests as appropriate.

The impact of SILC and CLC techniques on each Surg-TLX subscale was compared using Wilcoxon rank sum tests. SILC and CLC tool usability ratings were compared using Chi-square tests.


Patient demographics and operative time

Data on forty-eight procedures, 23 SILCs and 25 CLCs, were collected for this study. Additional ports were required for three SILC. Randomization stratified patients by age, gender, and BMI and was revealed to the surgical team after anesthesia induction for a double-blind RCT. Patient factors (age, gender, and BMI) and procedure duration (skin to skin) between the SILC and CLC groups did not differ statistically (Table 1).
Table 1

Mean ± standard deviation of patient factors and procedure durations for all cases (n = 48)



p value

CLC (n = 25)

SILC (n = 23)


47.7 ± 18.0

47.3 ± 17.4


Patient female (%)





30.6 ± 6.3

30.4 ± 6.4


Procedure duration (min)

73.2 ± 27.0

74.3 ± 26.2


aEqual variance t test

bFisher’s exact test

Surgeon workload


Subjective ratings from the Surg-TLX assessment tool are summarized in Table 2. Mean workload for each Surg-TLX subscale for SILC was equal or higher than CLC. Physical demand was 89 % higher (p = 0.02) in SILC procedures than CLC.
Table 2

Medians and interquartile ranges of Surg-TLX subscales and the procedure difficulty question

Surg-TLX subscales

CLC (n = 25) median (IQR)

SILC (n = 23) median (IQR)

% Increase in SILC versus CLC

p value

Mental demand

28 (18, 38)

43 (28, 47)



Physical demand

23 (18, 28)

43 (23, 48)



Temporal demand

23 (18, 28)

23 (18, 33)



Task complexity

23 (18, 43)

38 (23, 48)



Situational awareness

23 (18, 43)

28 (23, 38)




23 (18, 33)

28 (23, 33)




23 (15, 28)

35 (25, 43)



Minimum score = 0 (very low) and maximum score = 100 (very high)

Heart rate

A summary of the surgeon maximum heart rate data between SILC and CLC during the three operative time points is shown in Fig. 1. Postoperative maximum heart rate was 5.74 % lower than intraoperative heart rate in the CLC procedures (p = 0.038). Postoperative maximum heart rate was 13.74 % higher (p = 0.02) in SILC than CLC. Finally, change in maximum heart rate between the postoperative and intraoperative time points was more than 100 % higher in SILC than CLC (p = 0.02).
Fig. 1

Mean and standard deviation comparisons of the maximum heart rate were within the three time points of the surgery, and between SILC and CLC. Arrows indicate statistical differences between SILC and CLC for specified time points, or within SILC or CLC. Bracket indicates significant differences between SILC and CLC for the change in the maximum heart rate

Salivary cortisol levels

Summary of cortisol concentrations between SILC and CLC during the three operative time points is shown in Fig. 2. Intraoperative cortisol levels for the surgeon were 41.25 % higher in SILC than in CLC (p < 0.05).

Fig. 2

Boxplots (median, interquartile range, max, and min) of salivary cortisol levels (μg/dl) at the three time points of the surgery and between SILC and CLC. *Significant differences between SILC and CLC at specified time point

Tools usability

Comparing laparoscopic instruments usability between SILC and CLC, SILC tools were more frequently reported (p < 0.01) to be awkward to manipulate and unable to perform precision motions (Table 3).
Table 3

Frequency (% of cases) with which surgeon postoperatively reported problems with laparoscopic tools usability

Usability questions



p value

Instruments awkward to manipulate

1 (4 %)

16 (70 %)


Cannot perform fine/precision motions

1 (4 %)

9 (39 %)



SILC improves patient satisfaction compared to CLC [21], but the impact of the SILC technique on the surgeon has not been well studied. Our results show that SILC is physically more demanding for the surgeon than CLC.

This study was conducted in parallel with a randomized controlled trial allowing us to control for patients factors and limiting surgeon bias to which patient was offered SILC. Patient’s demographics and operative time have been previously suggested to affect surgeon stress and workload; however, no significance differences between the SILC and CLC groups were observed. Previous meta-analyses found that SILC requires a significantly longer time than CLC [21, 22]. In 2014, Koca found that surgeons require longer time to complete SILC than CLC (p < 0.05) [23]. With our result, we believe the surgeon has overcome the learning curve of both techniques and has reached the experience level on both techniques, SILC and CLC, even before the start of this study.

SILC was associated with significantly more awkward manipulations and caused more difficulty in performing the fine and precise movements when compared to CLC. Previous studies claim that single-incision techniques are more challenging than the conventional laparoscopic technique [10, 11], because of the instruments’ collisions, the narrow external surgical space for both surgeon hands and instruments [6, 24], and the limited range of motion [25]; this study confirms these with the instruments usability survey. Although Podolsky found that TriPort (which we used in our study) had the minimal elastic recoil force when the instruments released in maximum opposition in comparison with other reduced port techniques such as single-incision laparoscopic surgery (SILS) and single-port access [26] techniques, all SILC techniques have the common constraint on degrees of freedom. In contrast, multiple-port laparoscopy involves less elastic recoil and has a greater independence of movements [27]. The physical constraints of SILC could increase the difficulty of executing fine movements during surgery [24]. Moreover, the elastic recoil associated with SILC could increase the muscular fatigue and workload [28]. Elastic recoil and one incision instrumentation make the force exerted by the instruments on the abdominal tissue of the patients in SILC greater than CLC [29, 30]; however, this was not correlated with the postoperative pain or adverse patient outcomes. The physical constraints of SILC may explain Table 3 findings that SILC tools were more frequently associated with awkward manipulations [6, 24, 31]. Awkward manipulation and lack of precise movements may have a negative impact on both surgeon and patient safety. Awkward manipulation was shown to increase surgeons’ injury risks [32], and loss of precise movements may lead to longer operative time [24].

Salivary cortisol was used as an objective physiological measure of surgeon stress during the procedures. Although variability could occur from external and internal factors that affect the salivary cortisol levels [33, 34, 35], the sources of variability were limited by including only one surgeon in this study. Considering the diurnal rhythm changes in the cortisol level, we conducted treatment-received analysis for the first cases of the day only to match the times of the samples. During the procedure, SILC resulted in significantly higher salivary cortisol levels than CLC (Fig. 2), which may indicate that SILC is more stressful than CLC. Salivary cortisol has been shown to rise with increases in mental stress [36], which could also indicate that SILC is more mentally demanding than CLC. High mental stress may decrement the surgeons’ performance [37] and decision-making ability [23, 38, 39], which in turn may increase the operative duration and surgical errors that affect patient outcomes [10].

As it is another known objective measure of stress similar to cortisol [40, 41], the maximum heart rate was recorded. The maximum heart rate was found to be significantly higher postoperatively in SILC than in CLC. In addition, the difference in the mean of the maximum heart rate and the difference between pre-incision and postoperative times, and between intraoperative and postoperative were significantly higher in SILC than in CLC (p = 0.01 and p = 0.02, respectively). For CLC, the maximum heart rate increased from the pre-assignment to the surgery to intraoperative period and then dropped significantly after the intraoperative period to the postoperative period. If we compare that to the maximum heart rate pattern in the SILC, which is increasing from preoperative point till the end of the procedure, that may indicate that CLC is less stressful than the SILC. Previous work found that stress and workload increase the sympathetic tone which increases the heart rate [42]. Our study is in line with another study using the heart rate to measure the stress in the operating room [43]. These studies corroborate our findings that CLC may be less stressful to the surgeon than SILC may be.

Surg-TLX results demonstrated that SILC is 89 % more physically demanding than CLC in a statistically significant manner. Previous studies have shown that single-incision laparoscopic surgery is more technically demanding than conventional laparoscopic surgery for the surgeon or trainees [10]. Our results were supported by previous studies in simulation settings. In 2011, Montero found that SILC has 35–53 % higher than conventional laparoscopy as demonstrated by Surg-TLX [11]. Also, Riggle et al. [44] found that SILC caused greater mental strain than conventional laparoscopy. Koca et al. [23] found that SILC had significantly higher Surg-TLX subscales than CLC (p ≤ 0.01) and supported his results with electromyography (EMG) data which revealed that SILC was associated with higher muscular activity for the shoulder and upper arm than CLC. Many factors could increase the perceived physical workload including the instrumentation, but the high dependency of motion of the tools and high elastic recoil internally and externally in SILC require more muscular effort from the surgeon and leads to higher required physical workload on the surgeon hand and forearm [27]. Higher physical workload with SILC may increase the surgeon’s fatigue, muscular symptoms, and injuries [7, 45]. In 2012, Morandeira-Rivas [46] found that 81 % of the survey respondents reported musculoskeletal symptoms in two or more areas during and after laparoendoscopic single-site surgery (LESS). Surgeons’ physical injuries may impact surgical productivity by increasing days of absence and decreasing years of practice for surgeons. The resultant decrease in productivity will only worsen the problem of increasing need in the surgical workforce [47, 48].

To our knowledge, this is the first study to compare surgeon stress and workload between SILC and CLC in clinical setting. Additionally, the combination of data from validated objective and subjective measures of stress and workload together in one study follows the recommendations of many reviews in the ergonomics researches in surgery [37].

One limitation of this study is the enrollment of only one surgeon. However, the single-surgeon study eliminates the interpersonal variability and allows for better workload comparison between SILC and CLC. There is bias risk in the use of the subjective questionnaires by one surgeon. This questionnaire was well validated and used in the surgical suites, and the risk of the bias was minimized by the use of the physiologic objective methods. Moreover, double blinding and randomization increase the accuracy of the preoperative heart rate and salivary cortisol measures, so we used them as baseline values. Our results apply only to the single-incision laparoscopic cholecystectomy and do not include the application of single-incision laparoscopy for other surgical specialties. Additionally, some heart rate measures are missing from this study (available heart rate data for SILC: pre-randomization = 7, intraoperative = 13, postoperative = 11; for CLC: pre-randomization = 8, intraoperative = 10, postoperative = 12). The diurnal rhythm change in the salivary cortisol is one of the limitations in any stress study. We overcome the diurnal rhythm changes by recording the time of the samples conducted a treatment-received analysis for the salivary cortisol data after we excluded non-first cases of the day (excluded cases from CLC = 9; excluded cases from SILC = 2), and the significance remained consistent.

Based on our findings, it can be concluded that workload during CLC is lower than SILC for the surgeons. The increased burden from SILC procedures on the surgeon could decrease surgical performance and/or surgeon health. Unless significant changes to the current SILC occur with further studies on the impact of these changes on surgeons and patients, alternatives to the current SILC should be considered.



This study was funded partially by US Department of Health and Human Services, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases Grant (NIDDK Grant) (K23 DK 93553), Mayo Clinic’s Department of Surgery Research, and the Robert D. and Patricia E Kern Center for the Science of Health Care Delivery. The authors would like to thank Dr. Charles Bruce and Preventice® for the BodyGuardian® heart rate monitoring equipment and analysis. We would also like to thank all the surgeons who participated in this study and the Center for Clinical and Translational Science for its support through the REDCap survey (CTSA Grant UL1 TR000135).

Compliance with Ethical Standards


Dr. Hallbeck has research funding from Stryker Endoscopy. Dr. Bingener is supported through a research grant (NIDDK), specified research through Nestle and Stryker Endoscopy, has received travel support from Intuitive Surgical, and serves on the Surgeon Advisory Board for Titan Medical. Dr. Yu has research funding from Stryker Endoscopy. Bethany Lowndes is supported through research grants from AHRQ and Stryker Endoscopy. Andrea McConico, Drs. Abdelrahman, and Mohamed have no conflicts of interest or financial ties to disclose.


  1. 1.
    Chang SK (2014) Lee KY therapeutic advances: single incision laparoscopic hepatopancreatobiliary surgery. World J Gastroenterol 20(39):14329–14337PubMedCentralCrossRefPubMedGoogle Scholar
  2. 2.
    Bingener J, Ghahfarokhi LS, Skaran P, Sloan J (2013) Responsiveness of quality of life instruments for the comparison of minimally invasive cholecystectomy procedures. Surg Endosc 27:2446–2453PubMedCentralCrossRefPubMedGoogle Scholar
  3. 3.
    Kunkala M, Bingener J, Park M, Scott Harmsen W, McConico A, Reid Lombardo K (2013) Single-port and four-port laparoscopic cholecystectomy: difference in outcomes. Minerva Chir 68:155–162PubMedGoogle Scholar
  4. 4.
    Bucher P, Pugin F, Ostermann S, Ris F, Chilcott M, Morel P (2011) Population perception of surgical safety and body image trauma: a plea for scarless surgery? Surg Endosc 25:408–415CrossRefPubMedGoogle Scholar
  5. 5.
    McCrory B, LaGrange CA, Hallbeck M (2014) Quality and safety of minimally invasive surgery: past, present, and future. Biomed Eng Comput Biol 6:1–11PubMedCentralCrossRefPubMedGoogle Scholar
  6. 6.
    Tang B, Hou S, Cuschieri SA (2012) Ergonomics of and technologies for single-port lapaxroscopic surgery. Minim Invasive Ther Allied Technol 21:46–54CrossRefPubMedGoogle Scholar
  7. 7.
    Park A, Lee G, Seagull FJ, Meenaghan N, Dexter D (2010) Patients benefit while surgeons suffer: an impending epidemic. J Am Coll Surg 210:306–313CrossRefPubMedGoogle Scholar
  8. 8.
    Davis WT, Fletcher SA, Guillamondegui OD (2014) Musculoskeletal occupational injury among surgeons: effects for patients, providers, and institutions. J Surg Res 189:207–212CrossRefPubMedGoogle Scholar
  9. 9.
    Vijendren A, Yung M, Sanchez J (2014) The ill surgeon: a review of common work-related health problems amongst UK surgeons. Langenbecks Arch Surg 12:12Google Scholar
  10. 10.
    Santos BF, Enter D, Soper NJ, Hungness ES (2011) Single-incision laparoscopic surgery (SILS) versus standard laparoscopic surgery: a comparison of performance using a surgical simulator. Surg Endosc 25:483–490CrossRefPubMedGoogle Scholar
  11. 11.
    Montero PN, Acker CE, Heniford BT, Stefanidis D (2011) Single incision laparoscopic surgery (SILS) is associated with poorer performance and increased surgeon workload compared with standard laparoscopy. Am Surg 77:73–77PubMedGoogle Scholar
  12. 12.
    Rodrigues SP, Wever AM, Dankelman J, Jansen FW (2012) Risk factors in patient safety: minimally invasive surgery versus conventional surgery. Surg Endosc 26:350–356PubMedCentralCrossRefPubMedGoogle Scholar
  13. 13.
    Kohn LTCJM, Donaldson MS (2000) To err is human: building a safer health system. National Academy Press, Washington, DCGoogle Scholar
  14. 14.
    Carus T (2013) Current advances in single-port laparoscopic surgery. Langenbecks Arch Surg 398:925–929CrossRefPubMedGoogle Scholar
  15. 15.
    Miller K, Benden M, Pickens A, Shipp E, Zheng Q (2012) Ergonomics principles associated with laparoscopic surgeon injury/illness. Hum Factors 54:1087–1092CrossRefPubMedGoogle Scholar
  16. 16.
    Hart SG, Staveland LE (1988) Development of NASA-TLX (task load index): results of empirical and theoretical research. In: Hancock PA, Meshkati N (eds) Human mental workload. North Holland Press, AmsterdamGoogle Scholar
  17. 17.
    Hart SG (2006) Nasa-task load index (NASA-TLX); 20 years later. Proc Hum Factors Ergon Soc Annu Meet 50:904–908CrossRefGoogle Scholar
  18. 18.
    Wilson MR, Poolton JM, Malhotra N, Ngo K, Bright E, Masters RS (2011) Development and validation of a surgical workload measure: the surgery task load index (SURG-TLX). World J Surg 35:1961–1969PubMedCentralCrossRefPubMedGoogle Scholar
  19. 19.
    Trejo AE, Doné KN, DiMartino AA, Oleynikov D, Hallbeck MS (2006) Articulating vs. conventional laparoscopic grasping tools—surgeons’ opinions. Int J Ind Ergon 36:25–35CrossRefGoogle Scholar
  20. 20.
    Beurskens AJ, Bultmann U, Kant I, Vercoulen JH, Bleijenberg G, Swaen GM (2000) Fatigue among working people: validity of a questionnaire measure. Occup Environ Med 57:353–357PubMedCentralCrossRefPubMedGoogle Scholar
  21. 21.
    Pisanu A, Reccia I, Porceddu G, Uccheddu A (2012) Meta-analysis of prospective randomized studies comparing single-incision laparoscopic cholecystectomy (SILC) and conventional multiport laparoscopic cholecystectomy (CMLC). J Gastrointest Surg 16:1790–1801CrossRefPubMedGoogle Scholar
  22. 22.
    Trastulli S, Cirocchi R, Desiderio J, Guarino S, Santoro A, Parisi A, Noya G, Boselli C (2013) Systematic review and meta-analysis of randomized clinical trials comparing single-incision versus conventional laparoscopic cholecystectomy. Br J Surg 100:191–208CrossRefPubMedGoogle Scholar
  23. 23.
    Koca D, Yildiz S, Soyupek F, Gunyeli I, Erdemoglu E, Soyupek S (2015) Physical and mental workload in single-incision laparoscopic surgery and conventional laparoscopy. Surg Innov 22(3):294–302. doi:  10.1177/1553350614556363 CrossRefPubMedGoogle Scholar
  24. 24.
    Curcillo PG 2nd, Podolsky ER, King SA (2011) The road to reduced port surgery: from single big incisions to single small incisions, and beyond. World J Surg 35:1526–1531CrossRefPubMedGoogle Scholar
  25. 25.
    Ahmed MU, Aftab A, Seriwala HM, Khan AM, Anis K, Ahmed I, Rehman SU (2014) Can single incision laparoscopic cholecystectomy replace the traditional four port laparoscopic approach: a review. Glob J Health Sci 6(6):119–125PubMedGoogle Scholar
  26. 26.
    Montori A, Boscaini M, Gasparrini M, Miscusi G, Masoni L, Onorato M, Montori J (2000) Gallstones in elderly patients: impact of laparoscopic cholecystectomy. Can J Gastroenterol 14:929–932PubMedGoogle Scholar
  27. 27.
    Podolsky ER, Curcillo PG (2010) A comparison of independence of motion in single port access techniques. Surg Endos 24:S314–S701CrossRefGoogle Scholar
  28. 28.
    Curcillo PG, Wu AS, Podolsky ER, King SA (2011) Reduced port surgery: developing a safe pathway to single port access surgery. Chirurg 82:391–397CrossRefPubMedGoogle Scholar
  29. 29.
    Sun S, Dankelman J, Horeman T (2013) Differences in abdominal force between conventional and single port laparoscopy. In: Design of medical devices conference proceeding—Europe 2013Google Scholar
  30. 30.
    Horeman T, Kurteva DDKDD, Valdastri P, Jansen FW, van den Dobbelsteen JJ, Dankelman J (2013) The influence of instrument configuration on tissue handling force in laparoscopy. Surg Innov 20:260–267CrossRefPubMedGoogle Scholar
  31. 31.
    Vereczkel A, Bubb H (2003) Feussner H Laparoscopic surgery and ergonomics: it’s time to think of ourselves as well. Surg Endosc 17(10):1680–1682CrossRefPubMedGoogle Scholar
  32. 32.
    Berguer R (1999) Surgery and ergonomics. Arch Surg 134:1011–1016CrossRefPubMedGoogle Scholar
  33. 33.
    Kajantie E, Phillips DI (2006) The effects of sex and hormonal status on the physiological response to acute psychosocial stress. Psychoneuroendocrinology 31:151–178CrossRefPubMedGoogle Scholar
  34. 34.
    Kudielka BM, Schommer NC, Hellhammer DH, Kirschbaum C (2004) Acute HPA axis responses, heart rate, and mood changes to psychosocial stress (TSST) in humans at different times of day. Psychoneuroendocrinology 29:983–992CrossRefPubMedGoogle Scholar
  35. 35.
    Malhotra N, Poolton JM, Wilson MR, Ngo K, Masters RS (2012) Conscious monitoring and control (reinvestment) in surgical performance under pressure. Surg Endosc 26:2423–2429PubMedCentralCrossRefPubMedGoogle Scholar
  36. 36.
    Allen AP, Kennedy PJ, Cryan JF, Dinan TG, Clarke G (2014) Biological and psychological markers of stress in humans: focus on the Trier Social Stress Test. Neurosci Biobehav Rev 38:94–124CrossRefPubMedGoogle Scholar
  37. 37.
    Carswell CM, Clarke D, Seales WB (2005) Assessing mental workload during laparoscopic surgery. Surg Innov 12:80–90CrossRefPubMedGoogle Scholar
  38. 38.
    Wetzel CM, Kneebone RL, Woloshynowych M, Nestel D, Moorthy K, Kidd J, Darzi A (2006) The effects of stress on surgical performance. Am J Surg 191:5–10CrossRefPubMedGoogle Scholar
  39. 39.
    Byrne A (2013) Mental workload as a key factor in clinical decision making. Adv Health Sci Educ Theory Pract 18:537–545CrossRefPubMedGoogle Scholar
  40. 40.
    Vrijkotte TG, van Doornen LJ, de Geus EJ (2000) Effects of work stress on ambulatory blood pressure, heart rate, and heart rate variability. Hypertension 35:880–886CrossRefPubMedGoogle Scholar
  41. 41.
    Arora S, Sevdalis N, Nestel D, Woloshynowych M, Darzi A, Kneebone R (2010) The impact of stress on surgical performance: a systematic review of the literature. Surgery 147:318–330CrossRefPubMedGoogle Scholar
  42. 42.
    Valentini M, Parati G (2009) Variables influencing heart rate. Prog Cardiovasc Dis 52:11–19CrossRefPubMedGoogle Scholar
  43. 43.
    Rieger A, Stoll R, Kreuzfeld S, Behrens K, Weippert M (2014) Heart rate and heart rate variability as indirect markers of surgeons’ intraoperative stress. Int Arch Occup Environ Health 87:165–174CrossRefPubMedGoogle Scholar
  44. 44.
    Riggle JD, Miller EE, McCrory B, Meitl A, Lim E, Hallbeck MS, LaGrange CA (2014) Ergonomic comparison of laparoscopic hand instruments in a single site surgery simulator with novices. Minim Invasive Ther Allied Technol 21:1–9Google Scholar
  45. 45.
    Reyes DA, Tang B, Cuschieri A (2006) Minimal access surgery (MAS)-related surgeon morbidity syndromes. Surg Endosc 20:1–13CrossRefPubMedGoogle Scholar
  46. 46.
    Morandeira-Rivas A, Millan-Casas L, Moreno-Sanz C, Herrero-Bogajo ML, Tenias-Burillo JM, Gimenez-Salillas L (2012) Ergonomics in laparoendoscopic single-site surgery: survey results. J Gastrointest Surg 16:2151–2159CrossRefPubMedGoogle Scholar
  47. 47.
    Liu JH, Etzioni DA, O’Connell JB, Maggard MA, Ko CY (2004) The increasing workload of general surgery. Arch Surg 139:423–428CrossRefPubMedGoogle Scholar
  48. 48.
    Etzioni DA, Liu JH, Maggard MA, Ko CY (2003) The aging population and its impact on the surgery workforce. Ann Surg 238:170–177PubMedCentralPubMedGoogle Scholar

Copyright information

© The Author(s) 2015

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  • Amro M. Abdelrahman
    • 1
    • 3
  • Juliane Bingener
    • 2
  • Denny Yu
    • 1
    • 3
  • Bethany R. Lowndes
    • 1
    • 3
  • Amani Mohamed
    • 2
    • 3
  • Andrea L. McConico
    • 2
  • M. Susan Hallbeck
    • 1
    • 2
    • 3
    Email author
  1. 1.Robert D. and Patricia E. Kern Center for the Science of Health Care DeliveryMayo ClinicRochesterUSA
  2. 2.Department of SurgeryMayo ClinicRochesterUSA
  3. 3.Division of Health Care Policy and Research, Department of Health Sciences ResearchMayo ClinicRochesterUSA

Personalised recommendations