The increasing need for surgical services globally may be due to a decrease in the number of surgeons available to meet an increasing need [1, 2].

However, the plight is aggravated by attrition rates from surgical residencies, which can be as high as 20% [3, 4]. Residents who dropped out of surgical residency programs gave testimony that the subordination of teaching in favor of clinical duties was a primary reason for their decision [5].

Improving the quality of surgical training is debated as one of the most auspicious ways to increase the number of surgical residents [6].

Besides the fundamental impact on the attractiveness of the surgical profession to potential applicants and those enrolled in surgical residencies, training is essential to providing excellent and consistent quality of care. This is especially important in the context of minimally invasive surgery (MIS), where the learning curve is significantly slower than that of conventional open surgery [7].

The importance of adequate training in MIS is underlined by the fact that MIS is now used for many procedures, such as bariatric and reflux surgery, appendectomies, and cholecystectomies [8]. Robot-assisted surgery adds a new aspect to MIS that has only recently begun to gain considerable momentum [9]. However, the evolution of surgical training has not kept pace with developments, and the importance of adequate training in MIS remains paramount.

Although fellowships for MIS were introduced in the United States as early as 2007, significant deficits in MIS training still exist many years later [10]. A survey by Gardner et al. found most surgical residents felt unable to perform advanced laparoscopic surgery after completing their surgical training, and their instructors observed a decline in surgical competency compared to previous cohorts. Interestingly, both groups reported that trainees were given little autonomy to perform advanced procedures [11].

This trend was anticipated as early as 2009 by Hedrick et al., who noted a shift in the learning curve of laparoscopic surgery to the later years of training, potentially harming the learning of technical skills in the early years of surgical training, whereas comparable open surgery was mastered much earlier in training [12].

To gain significant MIS operative experience, specialized training inside and outside the operation room (OR) is required, as studies have shown the beneficial effect of adequate training on intraoperative performance [13,14,15].

Therefore, besides the obvious beneficial effect of training on the operative performance of surgeons, an adequate MIS education and training concept could attract new surgeons and retain residents within the residency programs. This nationwide survey aims to obtain an up-to-date overview of the MIS training reality in Germany, with a special focus on the satisfaction level with the training situation and corresponding influencing factors.

Materials and methods

This trial was conducted as an online survey through LimeSurvey© (Fig. 1) and adheres to the Checklist for Reporting Results of Internet E-Surveys (CHERRIES) guideline [16]. For recruitment of participants emails were sent to all publicly accessible email addresses of general, abdominal and thoracic surgeons and general surgical departments in Germany. The call for participation was repeated four times via the same email distribution list at regular intervals over a four-month period between July and October 2021. Participation in the survey was closed in November 2021. The survey was approved by the ethics committee of the Technische Universität Dresden (approval number: BO-EK-59012021).

Fig. 1
figure 1

Trial scheme

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Survey

The survey comprised up to 35 questions in German. At the beginning of the survey, all participants were informed that their participation was voluntary and anonymous. The questions were arranged into three thematic subgroups:

  1. 1.

    Questions on personal information, such as years of practice, specialization, and surgical experience for laparoscopic, thoracoscopic, and robot-assisted procedures. Response categories were “0”, “1–25”, “26–50”, “51–100”, and “ > 100 procedures.” In addition, the survey asked about the hierarchical status. Since this hierarchy system is a special feature of the German healthcare system, the response options are defined as follows:

    1. a.

      Resident resident surgeon in training without board certification

    2. b.

      Fellow surgeon with board certification working under supervision

    3. c.

      Attending surgeon surgeon with board certification supervising residents and fellows

    4. d.

      Head of department senior surgeon supervising a surgical department

  2. 2.

    Questions about the employing hospital or department, such as certification as an MIS center, size (measured by the number of patient beds and surgeons), and surgical capacity (measured by the number of all minimally invasive elective, robot-assisted, oncological, and emergency surgical procedures performed in one week).

  3. 3.

    Questions about the MIS training content and its implementation. We distinguished between a practical skills training curriculum in dry- or wet-lab conditions (outside the OR) and an intraoperative training curriculum during operations. We also queried the provision of teaching equipment, as well as practice times. Finally, participants were asked to rate their satisfaction with their respective training situation on a scale from 0 (not satisfied) to 100 (very satisfied). This included satisfaction levels for training both inside and outside the OR, as well as the provided time and training equipment.

Statistical analysis

The analysis included only fully completed survey data sets, resulting in no missing data. Statistical analysis was conducted using IBM SPSS Statistics version 28 (IBM Corp., Armonk, NY, USA). Continuous data normality was assessed using frequency distributions and the Kolmogorov–Smirnov test. Participant characteristics were presented as frequency distributions or median with interquartile ranges (IQRs) for continuous variables. A linear regression model was used to investigate factors influencing surgeons’ satisfaction, with significant variables from univariate analysis included in the multivariate analysis. A p-value of < 0.05 was considered statistically significant.

Results

Participants characteristics

The online survey included 1228 participants, of whom 1008 completed the survey while 220 dropped out (Table 1). The participants represented various hierarchy groups within the surgical profession, including residents (n = 263; 26.1%), fellows (n = 147; 14.6%), attending surgeons (n = 441; 43.8%), heads of departments (n = 153; 15.2%), and others (n = 4; 0.4%). The median length of time participants had worked in the surgical profession was 13 years (IQR 6–22).

Table 1 Participant and department characteristics
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The departments where participants had worked had a median of 14 (IQR 9–22) surgeons responsible for 45 (IQR 30–60) patient beds. Only 7.5 (IQR 5–10) surgeons per department performed MIS at least once a week. Additionally, 241 participants (23.9%) reported working at a center for MIS certified by a German surgical association. All participants (100%) reported to use MIS at their department, 995 participants (98.7%) used MIS for emergency surgery, 938 (93.1%) used MIS for oncological resections and 353 participants (35%) integrated robotic surgery at their department. Participants estimated to perform 15 (IQR 10–20) elective and five (IQR 4–8) MIS emergency procedures per week in their respective department. Among elective surgeries, three (IQR 2–5) procedures were oncological resections, and 3 procedures (IQR 2–4) were performed robotically assisted.

Surgical experience

Detailed characteristics of the cases performed as a primary surgeon or assistant are shown in Fig. 2 and Supplementary Material for each hierarchy level individually.

Fig. 2
figure 2

Ratio of operative experience in laparoscopic, thoracoscopic, and robotic cases as assistant or primary surgeon

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MIS training equipment and training time

Over half of the participants (n = 579; 57.4%) reported having access to MIS training equipment at their hospital (Table 2 and Supplementary Material). A box or pelvic trainer (n = 511; 88.3%) was the most frequently used training tool, while the endoscope and camera module (n = 185; 32%) were less frequently used. Virtual reality simulators for laparoscopic or thoracoscopic surgery (n = 132; 22.8%) and robot-assisted surgery (n = 115; 19.9%) were less commonly available training options. Surgical training involving animal or human organs (n = 61; 10.5%) or animals or body donors (n = 24; 4.1%) was rarely offered. Only a small number of participants (n = 78; 7.7%) were allowed to spend time during working hours for MIS training, and these participants spent a median of two hours per week (IQR 1–3) on MIS training.

Table 2 Availability and quality of training equipment, training curricula and time for training as reported by participants
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Skills lab MIS training

A skills lab training curriculum outside the OR existed in 300 cases (29.8%) (Table 2 and Supplementary Material). The most frequently included skills were basic laparoscopic skills (n = 281; 93.7%), such as instrument handling and simple suturing exercises. Simulated surgical steps or complete surgeries (n = 238; 79.3%) and practicing surgical assistance (n = 241; 80.3%) were also commonly included. A small proportion of participants reported that the curriculum included basic robotic skills (n = 81; 27%), surgical steps for robot-assisted procedures (n = 65; 21.7%), or surgical assistance (n = 70; 23.3%) in robot-assisted surgery.

Intraoperative MIS training

Among the participants, a quarter (n = 262; 26%) reported that their clinic or department had implemented an intraoperative MIS training curriculum (Table 2 and Supplementary Material). These curricula primarily focused on laparoscopic or thoracoscopic assistance (n = 243; 92.7%) and learning surgical steps (n = 251; 95.8%). Only a very few participants had access to an intraoperative training curriculum for assisting (n = 54; 20.6%) and performing (n = 49; 18.7%) robot-assisted surgery.

Subcohort analysis for MIS centers and robot-assisted surgery

An additional subcohort analysis including only participants who reported performing robotic procedures in their department or working in a certified MIS center is included in the supplementary material. Satisfaction with MIS training.

On a scale ranging from 0 (not satisfied) to 100 (very satisfied), participants expressed their satisfaction with the MIS training equipment and training times, the quality of skills lab or intraoperative MIS training with a median of 40 (IQR 11–65), 20 (IQR 3–50), 50 (IQR 21–75), and 58 (IQR 30–79), respectively (Supplementary material).

Factors determining satisfaction with skills lab MIS training

The study also investigated the contributing factors for satisfaction levels with skills lab and intraoperative MIS training for all surgeons, as well as trainees (residents and fellows, n = 410) and teachers (attendings and heads of departments, n = 594) groups individually.

All surgeons (Table 3)

A linear logistic regression model was used to analyze the factors that influenced the satisfaction levels of all surgeons. The multivariate analysis showed that several factors had an impact on their satisfaction. Among department-related factors, the number of beds (β − 0.137; 95% confidence intervals [CI] − 0.215 to − 0.059; p < 0.001) was negatively associated with the satisfaction levels of surgeons. Conversely, the number of surgeons performing MIS regularly (β 0.292; 95% CI 0.077 to 0.508; p = 0.008), access to MIS training equipment (β 5.246; 95% CI 1.171 to 9.321; p = 0.012), existence of a skills lab MIS training curriculum (β 12.572; 95% CI 7.263 to 17.881; p < 0.001), an intraoperative MIS training curriculum (β 6.24; 95% CI 0.822 to 11.658; p = 0.024), and time for training (β 7.644; 95% CI 0.915 to 14.374; p = 0.026) were significant positive factors. Performing laparoscopies as the first surgeon (β 3.254; 95% CI 0.472 to 6.036; p = 0.022) and being assistant in robot-assisted surgery (β 2.948; 95% CI 0.327 to 5.57; p = 0.028) also had a positive influence on satisfaction levels. Eventually, the hierarchy status (β 3.379; 95% CI 0.899 to 5.859; p = 0.008) was significantly associated with satisfaction levels.

Table 3 Linear regression analysis for all surgeons’ satisfaction with the skill lab MIS training situation (significant p-values marked bold)
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Trainee group (n = 410) (Table 4)

Analyzing the hierarchy groups separately, the multivariate analysis for significant factors influencing the satisfaction level of trainees with skills lab MIS training revealed that a higher number of surgeons employed at the department (β, − 0.452; 95% CI − 0.796 to − 0.108; p = 0.01) resulted in lower satisfaction levels within the trainee group. However, the existence of a skills lab MIS training curriculum (β 21.017; 95% CI 12.231 to 29.803; p < 0.001), an intraoperative MIS training curriculum (β 14.807; 95% CI 4.84 to 24.774; p = 0.004), and access to MIS training equipment (β 8.1; 95% CI 1.808 to 14.391; p = 0.012) were strong beneficial factors. Moreover, experience as the first surgeon in laparoscopic surgeries (β 3.741; 95% CI 0.797 to 6.686; p = 0.013) and as an assistant in robot-assisted surgeries (β 6.449; 95% CI 2.191 to 10.707; p = 0.003) also had a significantly positive influence on the satisfaction levels.

Table 4 Linear regression analysis for trainee’ satisfaction with the skills lab MIS training situation (significant p-values marked bold)
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Teacher group (n = 594) (Table 5)

The multivariate analysis showed that the number of employed surgeons (β 0.233; 95% CI 0.019 to 0.446; p = 0.033), the existence of a skills lab MIS training curriculum (β 9.258; 95% CI 2.736 to 15.78; p = 0.005), and the hierarchical status (β 3.891; 95% CI 0.387 to 7.395; p = 0.03) remained significant factors influencing the satisfaction levels of the teachers with skills lab MIS training.

Table 5 Linear regression analysis for teachers’ satisfaction with the skills lab MIS training situation (significant p-values marked bold)
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Factors determining satisfaction with intraoperative MIS training

All surgeons (Table 6)

In the multivariate analysis for factors influencing the satisfaction with intraoperative MIS training among all surgeons, significant factors included access to MIS training equipment (β 4.295; 95% CI 0.252 to 8.339; p = 0.037), offering an intraoperative MIS training curriculum (β 16.541; 95% CI 11.183 to 21.899; p < 0.001), and experience as the first surgeon in laparoscopic surgery (β 3.748; 95% CI 1.007 to 6.489; p = 0.007).

Table 6 Linear regression analysis for all surgeons’ satisfaction with the intraoperative training situation (significant p-values marked bold)
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Trainee group (n = 410) (Table 7)

The number of surgeons employed at the department (β − 0.57; 95% CI − 0.929 to − 0.21; p = 0.002) was a negative factor on satisfaction in the trainee group. On the other hand, the number of surgeons performing MIS regularly (β 1.087; 95% CI 0.407 to 1.767; p = 0.002), the existence of a skills lab MIS training curriculum (β 10.1; 95% CI 1.031 to 19.17; p = 0.029), an existing intraoperative MIS training curriculum (β 23.061; 95% CI 12.768 to 33.353; p < 0.001), and MIS training equipment (β 7.3; 95% CI 0.834 to 13.766; p = 0.027) significantly improved the satisfaction of the trainees with intraoperative MIS training.

Table 7 Linear regression analysis for trainees’ satisfaction with the intraoperative training situation (significant p-values marked bold)
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Teacher group (n = 594) (Table 8)

The only significant factor improving satisfaction within the teacher group was the existence of an intraoperative training curriculum (β 13.803; 95% CI 7.708 to 19.898; p < 0.001).

Table 8 Linear regression analysis for teachers’ satisfaction with the intraoperative training situation (significant p-values marked bold)
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Discussion

MIS is no longer considered an exotic or specialized surgical approach. At academic centers, MIS is being used for 94% of bariatric procedures, 83.7% of anti-reflux surgery, 77.1% of cholecystectomies, and 79.2% of appendectomies [8]. In Germany, appendectomies were performed laparoscopically in as many as 85% of cases [17]. However, the utilization of MIS varies widely, leading to a potential inequality in surgical care [18]. The ultimate goal should be to offer MIS to most patients and have most surgeons perform it. This requires thorough MIS education and training for all surgeons, especially since MIS requires an extended skill set including hand-eye-coordination, depth perception, diminished haptic feedback, specialized technological knowledge and surgical planning compared to open surgery.

However, the present survey indicates a different reality. Even though all participants reported using MIS in their department and almost all departments also offered MIS for emergency and oncological procedures, slightly over half (57.4%) of the participants had access to appropriate MIS training equipment, and only 29.8% used a skills lab MIS training curriculum, with a small proportion (7.7%) provided with time to train. The latter may already be a sign that we are already in a vicious cycle in which the shortage of surgical professionals further exacerbates the minimal margin of available time and human resources for training in addition to patient care.

The discrepancy between the availability of MIS training equipment and a corresponding standardized training curriculum has been previously demonstrated by Huber et al. in a survey. The survey reported that 52.8% (n = 140) of participating hospitals had laparoscopic training simulators, but only 43.3% (n = 103) provided a respective curriculum [19].

This concerning lack of training does not seem to be a solely German issue, as Ranjit et al. found that only 8% of first-year residents in the United Kingdom received laparoscopic skills training [20].

Even with existing training equipment, the quality of MIS training in the Skills Lab appears to be limited according to our study, as most reported training devices were box trainers, which are generally not suitable for more advanced training scenarios. Only a few respondents reported access to virtual reality simulators and surgical training opportunities on live animals or cadavers. Both simulation-based and in vivo training are essential for skill transfer to real-world operations [13, 21, 22]. The understanding that training to achieve laparoscopic competence should include realistic training, such as on live animals and cadavers, appears to be present in both residents and instructors [11]. Consequently, as early as 2006, most residents agreed in a survey that simulation training should be mandatory in surgical residency [23].

Despite this, our findings indicate that MIS training is still mainly conducted “on the job” during operations. Controversially, only a quarter of participants reported the existence of a structured intraoperative MIS training curriculum. Such inadequate training can lead to concerning results, as shown by Mattar et al. with 30% of fellows unable to perform a laparoscopic cholecystectomy independently and 56% unable to suture laparoscopically [24].

The question remains as to how this could have happened. Part of the problem is that German board certification for general or abdominal surgery has not yet required participation in an MIS course, nor is participation in laparoscopic or robotic procedures explicitly required. This makes it more difficult for surgeons in training to claim these types of procedures, as their supervisors and “teachers” are not obliged to provide this type of training or procedure.

The data from the present survey suggests that residents and to some extent even fellows are not able to gain sufficient operative experience as operating surgeons in MIS cases. Considering the increased popularity of robot-assisted surgery, the number of surgeons who have already participated in robot-assisted surgery exceeded the number of survey participants reporting robotic training equipment and curriculum by far. A very similar finding, with 60% of residents participating in robot-assisted surgery without having received any formal training, has been demonstrated before by Farivar et al. [25] Nevertheless, the number of operations performed has always been a benchmark in the training of surgeons. Fellow exposure to certain MIS procedures during training has been shown to increase the acceptance of such procedures, leading to a higher likelihood of performing them in the future [26]. Besides, being the operating surgeon and having operative autonomy have been identified as factors related to increased satisfaction among residents [27, 28].

Regarding satisfaction with the MIS training situation, our findings indicate that there are multiple factors influencing the satisfaction of surgeons. However, department-related factors, such as the number of beds and surgeons performing MIS regularly, showed a comparatively weak impact. Exposure to surgery and the existence of training curricula and equipment had the strongest effect on the satisfaction of surgeons with both, skills lab and intraoperative MIS training. Interestingly, satisfaction with skills lab MIS training also depended on hierarchy status.

The issue at hand is that there are disparities between trainees and teachers in their perceptions of different training methods and the quality of education [29,30,31]. These disparities may lead to different expectations and satisfaction with the training offered depending on the affiliation of the trainee or teacher groups. Our multivariate linear regression analysis for the trainee and teacher groups individually revealed that factors with a significant impact on satisfaction with extra- and intraoperative training were different between the two groups. In general, exposure to surgery played an important and beneficial role in influencing the satisfaction level within the trainee group. Participation in operations was one of the strongest influencing factors, supporting the findings of Ko and Perone. However, both trainees and teachers found the existence of a skills lab or an intraoperative MIS training curriculum, along with access to training equipment, essential for their satisfaction levels. Other significant factors, like department size or the number of surgeons performing MIS regularly, were relevant only for the trainee group and had comparatively weak influences on their satisfaction levels. Interestingly, larger departments with more patient beds and employed surgeons were at a disadvantage. Possible reasons for this include increased competition among employees for participation in operations and a greater number of complex cases beyond the capability of residents. However, the effect of this observation was comparatively weak compared to other factors, such as the existence of a training curriculum.

Limitations

The present study has several limitations that should be noted. First, the data was obtained through a survey, which can allow for a subjective interpretation of questions and responses. Consequently, the given answers may be biased by the subjective perspectives of respondents. Especially the estimation of surgery numbers per department, employees, and operative experience can be subject to very subjective alterations. However, the larger volume of participants and the even distribution of hierarchy groups provide a good balance for statistical outliers. Still, the generalizability could be compromised. We found 241 participants (23.9%) reporting to work at a certified MIS center but with currently 69 hospitals in Germany being certified as MIS center, we can assume an overrepresentation of MIS centers in our data. This overrepresentation of MIS centers, which must maintain MIS training equipment to obtain certification, may mask an even more worrisome general lack of MIS training availability.

Also, surveys are prone to inviting only a selected group of people of interest, which can lead to self-selection sampling bias. To reduce this bias, the survey was not spread using a surgical association or society by proxy, but all surgical departments and mostly even surgeons individually were contacted using the publicly available contact information. However, this approach meant that a response rate could not be reliably calculated. Finally, common-method bias cannot be completely ruled out, implying that there is a possibility that participants interpreted the underlying motivation of the survey and adjusted their responses accordingly [32].

Conclusion

This study provides the most comprehensive insight to date into the MIS training landscape in Germany. The results confirm that the predominant training methodology seems to be “training-on-the-job,” with a lack of training equipment, curricula, and dedicated time for training. Further analyses revealed factors with a significant impact on the satisfaction of surgeons with the respective training situations.

The lack of standardized MIS training in Germany, both in skills labs and in the OR, is worrysome. A potential cause might be the missing obligation to participate in MIS training and maybe even more the lack of obligation to teach sufficiently and to provide training time. As a consequence, it should be considered to include a mandatory participation in MIS training and MIS procedures to the requirements for the German surgical board certification. Furthermore, targeted interventions could be developed based on the results to improve surgeon well-being, increase surgical residency application rates, or avoid dropouts.