These results suggest that ambulatory hernia surgery is feasible and safe. Nevertheless, appropriate patient selection is essential to achieve such results. The selection criteria are not just medical but are also related to environmental and psychosocial factors [2].
In the literature, inclusion criteria vary according to authors. Bringman set an age limit of fewer than 75 years [3]; other authors, such as Mamie and Metzger, set an age limit of under 65 years [4]; this should minimise failure rates, especially in elderly patients. There were no age limits for other series, such as by Kurzer [5], Sanjay [6] or Kark [7]. In our study, advanced age was not a contraindication; we included all patients whose age was over 16 years. Some series, such as by Arroyo [8] included patients with ASA Grade III. In the French Society of Anaesthesia and Intensive Care (SFAR) recommendations, outpatient anaesthesia is preferentially intended for ASA Grade I and II patients. But some ASA Grade III patients can be eligible with some conditions: stabilised pathology under adapted treatment, negligible interferences between the intervention and the underlying pathologies and prior agreement between the surgeon and anaesthetist [9]. In most studies, bilateral or recurrent hernias were not a limitation to outpatient management. According to some authors, such as Drissi and Kark, these two factors were not associated with a higher risk of failure of the ambulatory procedure [7, 10–12].
In our study, patients under 16 years of age with an ASA Grade ≥ III, on long-term anticoagulants or under a medical treatment requiring its interruption before surgery, patients who were allergic to the anaesthetic drugs, had large VH of ≥ 10 cm or recurrent and strangulated hernias were not included.
In some series such as by Drissi or Hanes [13, 14], the principal exclusion criteria were: strangulated hernias undergoing emergency surgery, large VH, large inguinoscrotal hernias and the necessity of drainage. According to SFAR, the specific exclusion criteria for ambulatory hernia procedures are: complicated hernias undergoing emergency surgery, bulky and/or incarcerated inguinoscrotal hernias and large VH [9].
Hernias requiring drainage and bulky VHs with a wall defect of > 10 cm were excluded in our series.
The pre-anaesthesia evaluation should be carried out several days before surgery. All anaesthesia techniques can be performed, and there are no specific techniques for outpatient procedures, but drugs with a shorter duration of action are recommended [15]. Patients must undergo the same pre-operative monitoring and surveillance as those in inpatient care [16]. The surgical principles and techniques are the same as those performed in traditional inpatient surgery [1]. According to several authors, the procedure should be performed by an experienced surgeon or under the supervision of a senior physician [17]. In our study, all patients were operated on by a senior or under the supervision of a senior, aiming to reduce the operation duration and the morbidity rate in order to minimise the failure rate of outpatient management. The main surgical procedures performed in our day surgery unit are hernia surgery, proctology, laparoscopic cholecystectomy and lipoma surgery. We have only included in our work the hernia surgery that we performed exclusively by laparotomy. The surgical techniques varied according to the preferences of the surgeon.
After surgery, patients are transferred to a PIMR, where careful and continuous monitoring is carried out [18]. The monitoring time varies between patients and depends mainly on the type and duration of anaesthesia and the occurrence of intraoperative events [16]. The medical and surgical staff must carry out a standardised protocol for anticipatory control of POP and PONV [19–21]. Locoregional analgesia (LRA) is recommended. The surgeon should infiltrate the surgical wound with long-acting local anaesthetics as soon as possible, as this will significantly reduce the incidence of POP [22, 23]. Morphine use should be avoided as it can cause PONV and urinary retention [24]; it should be reserved for severe and resistant pain [15]. The use of NSAIDs significantly reduces PONV, particularly through opioid sparing [22, 24]. A therapeutic approach combining intraoperative droperidol and dexamethasone, while reserving strong antiemetics such as setrons for curative treatment, is quite satisfying in this context [22, 25].
Discharge from the PIMR is conditioned by several clinical monitoring parameters combined into scores, the most commonly used being the modified Aldrete score [26]. Once the patient has a score of 9 or higher, he/she can be transferred to the restroom [15, 16]. In our study, we also used the modified Aldrete score. The surgeon and the anaesthetist must approve the patient’s discharge after a medical evaluation, and a prescription can be delivered by one of the physicians of the structure [1]. The majority of authors agree that before discharge patients must be perfectly conscious, tolerate oral feeding, have spontaneous urination, do not require parenteral analgesia, and be able to walk on their own without assistance, with the mandatory presence of an adult companion [15, 20, 27–29].
In this context, the use of a predetermined score is recommended to facilitate this step. The most commonly used score is the PADSS ‘discharge’ score, which considers vital signs (heart rate and blood pressure), ambulation, POP and PONV, the eventual occurrence of bleeding, and nutrition. A score of ≥ 9 allows the patient to be discharged [29].
By analysing the different outpatient hernia surgery series, we found very encouraging results, with success rates ranging from 74 to 100% [10, 12, 17, 30, 31]. Drissi's multicentric study reported 6974 patients that underwent ambulatory GHR between 2011 and 2015, achieving a success rate of 96.4% [10]. A French study performed by Ngo on 242 patients undergoing ambulatory hernia surgery between June 2008 and October 2009 reported a success rate of 96.7% [30]. The failure rate of the ambulatory procedure is estimated by the rate of UAs and URs [10, 17]. In our study, the failure rate was 3.7% in GHR patients and 5.5% in VHR patients, while the success rate was 96.3% in GHR patients and 94.5% in VHR patients.
The rate of UA ranges from 0% and 19% in the literature [7, 10, 17, 30, 32–34]. Ngo et al. reported a UA rate of 2.6% [30]. Drissi et al. included 6974 patients in their study and reported a UA rate of 3.6%. The main causes of failure were: headache and vertigo (20.6%), POP (15.7%), acute urinary retention (9.9%), supporting problems (7.6%), bleeding (4.6%), PONV (4.2%), and late discharge from the operating room (3.4%)[10]. A Belgian study published in 2018 by Van Caelenberg et al. [34], including 5156 patients that underwent ambulatory surgery, had a missed discharge rate of 2.89%. The main causes for UA were: socioeconomic and supporting problems (distance from the hospital, companion problems, late discharge from the operating room, etc.) in 45.52%, POP in 11.72%, bleeding and abdominal wall hematoma in 10.34%, acute urinary retention in 3.3%, PONV in 2% and medical causes in 5.52% (pulmonary embolism, pneumonia, epilepsy, syncope, etc.).
The UR rate ranges from 0–9% in the literature [17, 30, 33–37]. In Ngo's series, a rate of 0.7% of rehospitalisations was observed [30]. A multicentre Finnish study by Mattila et al., including more than 6500 patients having outpatient surgery in 2009 for several surgical pathologies including hernia, found a rate of post-discharge consultations of 5.9% and a UR rate of 0.7% [35]. The different UR causes in the literature include: bleeding and abdominal wall haematoma, acute bowel obstruction, POP, acute urinary retention, headache and vertigo, fever and thromboembolic events [5, 6, 8, 35, 38–42].
To improve results and decrease the rates of UA and UR, several series have studied the predictive factors of failure of the ambulatory procedure [10, 33, 34, 43–45]. Drissi et al. [10] analysed these factors through a multivariate statistical study and concluded that an ASA Grade ≥ III, bilateral and/or strangulated hernias and spinal anaesthesia were predictive factors for failure.
Van Caelenberg et al. [34] found a failed discharge rate of 2.89%, related to longer operative duration, late discharge from the operating room and ASA Grade ≥ III. In Whippey's Canadian study published in 2013 [33], including 20,657 patients undergoing ambulatory surgery, the failed discharge rate was 2.67%. Predictive factors for failed discharge were: duration of surgery of more than one hour, ASA Grade ≥ III, advanced age (> 80 years), and a body mass index (BMI) between 30 and 35 kg/m². On the other hand, active smoking was associated with a reduced probability of failed discharge.
Our study did not observe any statistically significant variable as a predictor of discharge failure by multivariate analysis. We summarise in Table 7 the results of the different series according to morbidity and success or failure of the ambulatory procedure.
Table 7
Results of the different series according to morbidity and success or failure of ambulatory procedure.
Serie | N | Morbidity | Mortality | Succes rate | Unplanned admissions (UAs) | Unplanned rehospitalisations (URs) |
Ngo et al [17] | 242 | 3,3% | 0% | 96,7% | 2,6% | 0,7% |
Drissi et al [22] | 6974 | 7,3% | - | 96,4% | 3,6% | - |
Van Caelenberg et al [54] | 5156 | - | - | - | 2,89% | - |
Mattila et al [67] | 6659 | - | - | - | 5,9% | 0,7% |
Whippey et al [57] | 20657 | - | - | - | 2,67% | - |
Majholm et al [76] | 57709 | - | 0,0004% | - | - | 1,21% |
De Lange et al [83] | 3284 | 5,9% | 0,12% | - | - | - |
Our serie (groin hernia repair) | 1020 | 2,4% | 0% | 96,3% | 3% | 0,7% |
Our serie (ventral hernia repair) | 274 | 3,6% | 0% | 94,5% | 4% | 1,5% |
The benefits of outpatient hernia surgery are currently recognised, as shown by the very high satisfaction rates of patients operated on in this mode, which are over 90% in most series [1, 23, 29, 46–48].
Ambulatory management decreases the rate of nosocomial infections. Indeed, early patient discharge reduces the probability of being exposed to infection [1]. It also allows more comfortable care, inducing fewer daily changes in the patient's life and environment than conventional surgery [49].
Ambulatory surgery is also of major economic benefit. This is partly due to reduced hospitalisation expenses, such as parenteral drug prescriptions and hygiene and maintenance costs [1, 50]. It also allows for better hospital resource management by devoting full hospitalisation bed capacity and nursing staff energy to patients with more serious pathologies [50].