Postoperative outcomes of inguinal hernia repair performed by surgical residents in routine clinical practice: a retrospective single-center analysis

Introduction

Inguinal hernia repair is one of the most common surgical procedures performed worldwide and the lifetime risk for men developing the condition is around 25 % [1]. Around 250,000 inguinal hernia repairs are performed in Germany each year [2]. Different techniques are used, and the choice depends on the age of the patients, symptoms, size of the hernia, and preference of the surgeon [3], 4]. Two of the most common techniques are the open Lichtenstein repair and the laparoscopic transabdominal preperitoneal (TAPP) patch technique [5], 6].

Due to the frequency of the condition and the operation, it is important for surgical trainees to learn about the diagnosis and treatment of inguinal hernias early on in their training. Inguinal herniotomy using the Lichtenstein technique is often considered as an initial procedure for hernia surgery and is also included in the list of procedures required for surgical board certification in Germany. However, it involves considerable risks, such as damage to the spermatic cord or testicular blood supply and the development of chronic pain [7], 8]. In addition, minimally invasive treatment of the inguinal hernia is increasingly preferred whenever possible, especially among younger adults [9], 10]. This is seen as more demanding than open treatment, so it is usually taught later during surgical training [11].

Hospitals specializing in hernia surgery should ideally provide both minimally invasive and open approaches for inguinal hernia repair to ensure comprehensive patient care and individualized treatment selection [12]. The availability of both techniques not only allows surgeons to tailor the procedure to patient-specific factors but also has direct implications for surgical education. To become well rounded and competent in hernia surgery, residents must be adequately trained in both techniques and gain experience in the nuances, benefits, and limitations of each approach [13]. This ensures that future surgeons will be well prepared to manage a wide range of clinical scenarios and can offer patients the most appropriate surgical option.

However, in times of increasing demands for patient safety, quality management, and cost efficiency, the question of whether the involvement of junior doctors in operations is safe and efficient is increasingly coming into focus. Studies have already shown that the involvement of junior doctors in operations often leads to longer operating times [11], 14]. Extended operating times can result in an increased rate of surgical-site infections [15]. Particularly in connection with mesh implants, this could result in an increase in mesh infections and thus postoperative morbidity, as shown for other implants [16]. Therefore, in most countries, a specialist standard applies, which means that all operations must be performed to the standard of a board-certified surgeon. This is usually ensured by surgical trainees operating under supervision and not alone.

The aim of this retrospective study was to evaluate the postoperative outcomes of inguinal hernia repair performed by surgical residents in comparison to board-certified surgeons. Focus was given to postoperative morbidity in a real-world clinical setting. To ensure a representative depiction of routine surgical practice, the analysis included both hernia repair techniques performed (the Lichtenstein procedure and TAPP), as well as recurrent and bilateral hernias without differentiating between surgical approaches.

Materials and methods

Results

Patient characteristics

We recorded 388 hernia-repair surgeries between 2014 and 2020 in the department. Of those surgeries, 228 were laparoscopic (TAPP), and 159 were open (Lichtenstein) (Figure 1). The mean age of the study population was 58 ± 17 years, 367 patients were male (94.6 %), and the mean BMI was 25 ± 4 kg/m². Furthermore, 155 patients (39.9 %) had risk factors, including smoking (25.3 %), viral hepatitis (3.4 %), HIV (2.3 %), and alcohol consumption (9 %). 268 patients had an ASA score of ≤2 (69.8 %).

Figure 1:

Study flow chart.

There were statistically significant more female patients in group B (p=0.035). Furthermore, COPD was significantly more common in group A (p=0.009). Apart from those parameters, the groups did not show statistically significant differences in age (p=0.613), BMI (p=0.468), cardiovascular disease (p=0.462), liver cirrhosis (p=0.173), diabetes mellitus (p=0.324), and ASA score (p=0.315). The details are shown in Table 1.

Table 1:

Patient characteristics.

	Total (%) n=388	Group A (%) n=110	Group B (%) n=278	Pearson chi-squared, df	Cramer’s V	p-Value
Gender				3.874 (1)	0.100	0.035a
Male	367 (94.6)	108 (98.2)	259 (93.2)
Female	21 (5.4)	2 (1.8)	19 (6.8)
Comorbidities
Cardiovascular disease	179 (46.1)	54 (49.1)	125 (45.0)	0.540 (1)	0.037	0.462
COPD	18 (4.6)	10 (9.1)	8 (2.9)	6.877 (1)	0.133	0.009
Liver cirrhosis	19 (4.9)	8 (7.3)	11 (4.0)	1.861 (1)	0.069	0.173
Renal failure on dialysis	4 (1.0)	1 (0.9)	3 (1.1)	0.022 (1)	0.008	0.681a
Without dialysis	28 (7.2)	10 (9.1)	18 (6.5)	0.806 (1)	0.046	0.369
Diabetes mellitus	40 (10.3)	14 (12.7)	26 (9.4)	0.971 (1)	0.050	0.324
Dementia	6 (1.5)	3 (2.7)	3 (1.1)	1.406 (1)	0.060	0.224a
Prostatic cancer in the last 5 Years
Yes	17 (4.4)	4 (3.6)	13 (4.7)	0.203 (1)	0.023	0.445a
Prostatectomy
Yes	15 (3.9)	4 (3.6)	11 (4.0)	0.022 (1)	0.007	0.573a
Risk factors
Smoking	98 (25.3)	26 (23.6)	72 (25.9)	0.214 (1)	0.023	0.644
Viral hepatitis	13 (3.4)	4 (3.6)	9 (3.2)	0.039 (1)	0.010	0.529a
HIV	9 (2.3)	3 (2.7)	6 (2.2)	0.113 (1)	0.017	0.493a
Alcoholism	35 (9.0)	11 (10.0)	24 (8.6)	0.179 (1)	0.022	0.672
ASA score (n=384)				1.008 (1)	0.051	0.315
ASA 1–2	268 (69.8)	72 (66.1)	196 (71.3)
ASA≥3	116 (30.2)	37 (33.9)	79 (28.7)
	Total n=388	Group an n=110	Group B n=278	F	p-Value
Age in years (mean ± SD)	58 ± 17	59 ± 18	58 ± 16	0.256	0.613
BMI (kg/m2) (mean ± SD)	25 ± 4	25 ± 5	25 ± 4	0.528	0.468

1. COPD, chronic obstructive pulmonary disease; BMI, body mass index; SD, standard deviation; HIV, human immunodeficiency virus; ASA, American Society of Anesthesiologists. The chi-squared test was used to analyze the categorial variables. Pairwise comparisons between the groups were made with Bonferroni corrections. For continuous variables, one-way ANOVA analysis with Bonferroni correction was performed. ^aFisher’s exact test was used.

Discussion

This retrospective study found no influence of the level of training of the surgeon on postoperative outcome after inguinal hernia repair. Surgery done by a surgical trainee, always supervised by a board-certified surgeon, was not a risk factor for higher intra- or postoperative complications for the classical open Lichtenstein repair procedure or the laparoscopic TAPP approach. The TAPP approach seems so be a protective factor for postoperative complications based on the multivariate analysis. However, other studies have shown that minimally invasive inguinal hernia repair procedures can be performed safely by residents [19], 20].

The postoperative complication rates after inguinal hernia repair are low compared to those of other general or visceral surgical procedures, which seems to make it an exemplary surgical procedure for educating surgical trainees. In recent literature, the rates vary from under 1–10 % (all degrees of complication summarized) and depend on the type of surgery [21], 22]. Weyhe et al. showed that major complications classified as CDC three or higher only occurred in around 20 % of cases [23]. We observed a complication rate of 9.8 %, and the rate of major complications was only 1.8 % of patients, which is in accordance with recent literature.

In the univariate analysis, TAPP was identified as a protective factor, which is in line with recent literature. Ashrafi et al. showed that patients undergoing TAPP had significantly lower rates of seroma, hematoma, and wound infections compared to patients receiving a Lichtenstein repair [21]. In contrast, Scheuermann et al. found no difference in postoperative complications between the techniques [24]. Our analysis was done with all inguinal hernia repairs pooled, and TAPP was performed significantly more often by board-certified surgeons, so our study does not answer the question of whether TAPP performed by residents would be associated with an increased risk of complications.

A wide range of risk factors have been described for perioperative complications in inguinal hernia repair. Known risk factors include patient age, BMI, diabetes, smoking, and duration of surgery [23], 25]. Previous prostatectomy is a risk factor for males developing inguinal hernia [26], 27]. Some studies also describe it as a risk factor for increased perioperative complications in minimally invasive hernia repair [28]. In a meta-analysis, Kasakewitsch et al. showed that patients with a previous prostatectomy had increased operation times and a higher rate of postoperative complications [29]. On the other hand, the meta-analysis by Aiolfi et al. showed no increased risk for intra- and postoperative complications for minimally invasive surgery after prostatectomy [30].

Nonetheless, surgical trainees needed 24 min more time on average to perform a unilateral TAPP, which was statistically significant. For bilateral TAPP, the duration of surgery was 16 min longer for the surgical trainee group, but the difference was not statistically significant. For Lichtenstein repair, no difference was observed between the groups. This finding is consistent with other studies [11], 14].

Prolonged operative time could be a risk factor for postoperative SSI. Especially in conjunction with mesh implants, an SSI could lead to infection of the implanted mesh. Kohno et al. showed a significantly increase of SSI per 1 h increase in operating time [31]. Christou et al. discussed the types of mesh implants and types of hernia as risk factors for SSI [32]. They analyzed over 21,000 patients from the French Hernia Club Registry, and the SSI rate was 0.24 % for open repair and 0.19 % for minimally invasive repair. They did not find any significantly risk factors in their univariate regression analysis [32]. Additionally, they found no connection between SSI and the type of implanted meshes.

Since men make up most patients undergoing inguinal hernia repair, protecting the spermatic cord is of particular importance. In our cohort, we found 2 cases (0.5 %) of injuries to the spermatic cord. Both cases were operated on by board-certified surgeons. Damous et al. found no impact of bilateral hernia repair using the Lichtenstein procedure or TAPP on male fertility [33]. Overall, the complication of injury to the spermatic cord or the resulting testicular atrophy appears to be so rarely described in the literature that it was not included as single factor in the analyses within the scope of reviews and meta-analyses [24], 34], 35].

The rate of hernia recurrence was reported as 1.2 % for TAPP by Andresen et al. and 4.7 % by Pokorny et al. [34], 35] For the Lichtenstein procedure, the reported recurrence rates are between 0 and 9 % [21], 35]. For both methods, the reported recurrence rates have wide distributions. We observed a recurrence rate of 2.1 % for both methods, which is within the range reported in the literature, and there was no difference between the resident and board-certified surgeon groups.

Overall, however, during the study period, board-certified surgeons performed more than twice as many inguinal hernia repairs as residents. Unfortunately, this reflects the reality of surgical training [36], 37]. Also, this reflects to some extent insurance status of patients, since privately insured patients are uniformly operated by board-certified surgeons. Currently, hospitals must also pay attention to cost-effectiveness and efficiency. In particular, the extension of operating time, which can result from the involvement of assistant doctors in the operation, could pose an economic problem for many surgeries involving surgical education [38], [39], [40].

To successfully integrate surgical training into daily clinical practice, several conditions must be met. Notably, structured supervision by experienced surgeons, the consistent incorporation of simulation-based training (such as hernia models), and institutional support that aligns educational needs with operational efficiency are essential [41], 42]. A recent systematic review confirmed that simulation-based training improves technical proficiency while maintaining patient safety and reducing errors in real clinical settings [43]. Additionally, real-time instructor feedback has been shown to optimize learning curves in simulation environments, further enhancing readiness for actual procedures [44]. Such modern educational approaches may not only benefit medical students but could also be valuable in the context of specialist-level surgical training.

Conclusions

While the involvement of surgical residents leads to a longer operation time for laparoscopic inguinal hernia repair, there is no evidence suggesting an increased risk of postoperative complications. Both resident-performed and specialist-performed surgeries demonstrated low complication rates, which aligns with established standards for hernia-repair outcomes. Our findings reflect the real-world clinical and educational setting of a tertiary care center in Germany, where surgical residents predominantly perform open inguinal hernia repairs, while board-certified surgeons more frequently conduct minimally invasive procedures. Importantly, both approaches were proven to be safe when performed by residents under appropriate supervision. These results highlight the feasibility of implementing structured surgical training within routine clinical practice while ensuring both patient safety and high-quality resident education. To sustain surgical training in daily practice, healthcare institutions should implement structured curricula alongside mentorship, integrate simulation-based preparation, and ensure sufficient hands-on experience. Additionally, trainees should engage in specialized continuing education offered by professional societies to complement their clinical training.