Prehabilitation: Enhancing Recovery and Outcomes in Hernia Surgery

Abstract

As patients get older and clinical situations become more complex, optimization before surgery is paramount. Physicians always tried to improve the pre-surgical status of patients, but they followed stochastic models. The structured intervention to improve nutritional status, cardiorespiratory and neurocognitive function and minimize frailty has been called prehabilitation. It improves functional status before and after surgery in multiple settings suggesting a possible lower length of stay, as documented by several RCTs, and improved outcomes. Hernia surgery has evolved immensely in the past decades, providing solutions for patients and situations not long ago deemed inoperable. For incisional hernia, especially if complex, the recurrence rate may increase to 60%, most of which occur in the first 2 years. The difficulty rises for each repair attempt, so teams have their best opportunity in the first intervention. Most complex hernias started as simple ones. Prehabilitation interventions may contribute to outcome optimization in hernia surgery.

1. Introduction

Globally, human populations are getting older. In 2022, in Europe, one-fifth of the population was over 65. By 2030, globally, older people will outnumber children under 10; by 2050, they will double their numbers [1].

Naturally, as people get old, they accumulate numerous comorbidities, and frequently enough, they must undergo surgery for various illnesses. Surprisingly, older adults do not seem as sick as they used to [2]. Nonetheless, older people do accumulate more comorbid states than their younger counterparts. As the elderly population increases, this poses a massive concern in healthcare, most prominently surgery. How can we improve outcomes in an aged and sick population?

Every clinician, especially surgeons, always tries to improve the patient’s condition after an intervention. Robert Topp and colleagues proposed, as early as 2002, the “process of enhancing functional capacity of the individual to enable them to withstand an incoming stressor” as a definition for prehabilitation [3]. As this definition points out, prehabilitation started focused on patients’ physical function and consisted of a varied range of pre-surgical exercise programmes. Karin Valkenet and colleagues demonstrated, in a 2011 systematic review, that “preoperative exercise therapy” can improve postoperative outcomes [4]. Not long after, Daniel Santa Mina, in a systematic review back in 2014, identified several studies in which preoperative whole-body exercise programmes showed promise in improving postoperative outcomes such as pain, length of stay and physical function [5]. Carli and Zavorsky depicted very successfully the rationale for prehabilitation (Figure 1) [6].

Figure 1.

Visual representation of the rationale for prehabilitation. Reproduced with permission from the lead author of Carli and Zavorsky [6].

In recent years, prehabilitation has shifted from focusing exclusively on physical conditions to entail global health improvement. Multimodal approaches include not only how fit a patient is but also how well-nourished and controlled his comorbidities are and his or her psychological status. To comprise all these dimensions, the prehabilitation definition had to evolve. The most recent and consensual definition of prehabilitation might be Durrand’s: every intervention that aims at “enhancing general health and wellbeing prior to major surgery” [7].

We can only aim if we have a target. Risk assessment, especially in high-risk patients in complex hernia surgery, is part of the patient’s journey and crucial to shared decision making and informed consent [8]. In potentially complex patients, the authors adopted the multidisciplinary evaluation pathway described in Figure 2.

Figure 2.

Potentially complex hernia patient pathway. NSQIP—National Surgical Quality Improvement Project; mFI—Modified frailty index; ECOG—Eastern cooperative oncology group. Adapted with permission from Lages et al. [9].

The concept of enhancing recovery after surgery by minimizing surgical stress response was proposed in the early nineties by Henrik Kehlet [10]. Standard recovery protocols soon followed, focusing on various interventions implemented at or after surgery. As the preoperative period gained importance, however, some interventions were included prior to surgery as part of a truly multimodal approach to optimization of recovery and, therefore, results. These interventions resulted in savings and even reduced complications and mortality in some specific surgeries [11].

The first evaluation of a patient with a hernia should include a comprehensive history and physical examination. This process should include due identification and characterization of the main problems and their valuation by the patient, based chiefly on the impact on activities of daily living or quality of life. These are paramount in a value-based healthcare paradigm. Some abdominal wall reconstructions are so complex and potentially hazardous that it is essential to discuss with the patient what he will gain by being operated on or what he might lose if so. As in finance, there are risk-averse and intrepid patients, and our joint decision must match their risk profile.

Medical and surgical history, a careful systems review and a medication review frequently identify conditions under the radar. Suppose risk factors such as obesity, diabetes, steroid use, tobacco use or undernourishment are identified. In that case, these patients are referred to the specific health professional for further evaluation and a recovery programme implementation.

In patients with highly symptomatic hernias or multiple episodes of incarceration, achievement of prehabilitation goals becomes secondary, and surgery ensues. However, patients must acknowledge the risk profile of the operation. Knowledge of a high probability of failure should prompt surgical teams to carefully choose techniques so that a later intervention is not even more difficult.

2. Weight management

Obesity poses a specific problem for abdominal wall hernia repair. Obese patients have an increased abdominal perimeter and a higher abdominal fat volume, leading to higher abdominal wall pressure [12]. Obesity patients have sarcopenia. Obesity produces a chronic low-grade inflammatory response with consequences in the immune response and alterations in the healing process [13, 14]. The overall complication rate is also higher in patients with body mass index (BMI) greater than 30, especially surgical-site infection (SSI), with an incidence of 23% for colorectal and other general surgery procedures [15].

Increased wound morbidity is tied to body mass index (BMI), as there is a linear relation between surgical-site infection (SSI) or surgical-site occurrence (SSO) and obesity. SSI also increases risk recurrence twofold; late costs will undoubtedly rise [16].

The recurrence rate at 12 months may be as high as 52% in patients with BMI higher than 30 Kg/m². Of these, around 30% will require surgery [17]. A systematic review of the literature in 2021 identified differences in hernia recurrences between BMI thresholds. The risk of recurrence in ventral hernia repair is 2.5-fold higher in patients with BMI greater than 25 when compared to those with BMI equal to or inferior to 25—the risk triples in patients with BMI over 40, compared with a lower BMI [18].

Even if surgery is minimally invasive, the risk still exists of trocar site hernia [TSH] formation. Early studies indicated an incidence of symptomatic TSH hernias of up to 5%, but most authors agree that this is a highly underdiagnosed problem [19].

A recent study revealed that incidence may be as high as 23%, but fewer than 50% are symptomatic. Tonouchi et al. suggest that obesity and diabetes may increase TSH, underlining the technical difficulty in closing port incisions in high BMI patients. A more recent study by Ciscar et al. determined that obesity and age over 70 constitute independent risk factors for TSH [20, 21].

There is a debate about the best pathway to treat hernia in obese patients. Obesity increases the risk of recurrence, but delaying hernia repair until the patient reaches good weight control can allow for hernia complications during this period [22]. It seems intuitive to address obesity prior to hernia surgery. The difficulty lies in setting evidence-based thresholds. It is unreasonable to expect that most patients lose enough weight to bring their BMI down to normal or even overweight, especially on their own. Maskal and colleagues found that free weight management programs can help but are insufficient to address obesity independently [23]. No patient over BMI 35 kg/m² should undergo elective hernia surgery before an attempt to control weight. Weight loss is an essential factor in prehabilitation before hernia surgery. The prehabilitation must include low-calorie diet and physical exercise as a first step. However, diet and physical exercise have poor long-term weight loss results in morbidly obese patients and patients with BMI higher than 35 Kg/m² will rarely respond to nutritional and behavioral interventions alone. Besides, patients with symptomatic hernias are at risk of hernia complications, so weight loss must be reached in the shortest possible time.

Bariatric surgery is an adequate treatment to achieve good weight loss quickly with good long-term results [24]. Morbidly obese patients [BMI > 35 kg/m²] with symptomatic hernias must be referred to bariatric units for weight loss before elective hernia surgery. If emergent hernia surgery is warranted, obese patients should be referred to the bariatric unit as soon as possible after the hernia surgery.

3. Diabetes management

Diabetes is a well-known risk factor for SSO, especially infectious occurrences, as a higher surgical mesh infection rate in abdominal wall repair [25]. Acute glycaemic control is paramount, as infectious complications increase with blood glucose levels. Hyperglycaemia impairs neutrophil action, and the host’s immune response to infection, particularly in the presence of a foreign body [mesh], will be hampered. Without hernia-specific evidence, there are strong recommendations that blood glucose levels should be kept below 200 mg/dL [26]. A meta-analysis of randomized trials showed no overall advantage in adopting a more intensive blood glucose lowering regime in studies with non-diabetic or mixed patient populations. There was, however, a reduction in SSI with intensive regime in studies involving diabetic patients. Nevertheless, the studies had considerable heterogeneity, and complications such as hypoglycemia were more significant [27].

Acute glycaemic control is essential, but chronic management of diabetes is also crucial. Based on a 2006 study by Dronge and colleagues Robert Martindale and Clifford Deveney, they proposed an HbA1c threshold of 7%, above which surgery should be postponed until better glycaemic control. Mike Liang and colleagues propose a higher threshold of 8% [28, 29]. No relevant studies show a relation between HbA1c levels and hernia surgery outcomes. Martindale and Deveney’s proposal come from a study of NSQIPs non-cardiac surgery, and outcomes ranged from pneumonia to urinary tract infection, and Liang’s proposal originates from a consensus. CDC guidelines on SSI, in 2017, failed to propose a recommendation on this issue based on the lack of evidence. The more recent systematic review from the European Hernia Society (EHS) Prehabilitation Project, although meeting with similar problems, did propose level 2 evidence for an HbA1c lower than 7%. That recommendation, however, comes from Liang et al.’s consensus that HbA1c higher than 6.5% increases complications in a varied array of surgeries. Participants agreed that, in diabetic patients, we should aim at a maximum of 7% preoperative HbA1c levels [30].

4. Smoking cessation

Smoking is a well-established as a risk factor for complications after surgery. Smoking cessation before surgery results in a risk reduction of 41% of postoperative complications. The longer the interval without smoking, the more significant the risk reduction [31]. After an analysis of the American College of Surgery National Surgical Quality Improvement Project (NSQIP) database, Park et al. demonstrated that obesity and smoking increased SSI incidence in ventral hernia repair. They also demonstrated smoking as a risk factor for recurrence in ventral hernia repair [32].

As far back as 2007, Lindström and colleagues demonstrated, after analysis of the Swedish inpatient register, that smoking increased complication rate even in inguinal hernia surgery. In a more recent study from NSQIP, authors concluded that, in inguinal hernia repair (both open and laparoscopic), “failure to quit smoking prior to surgical repair is associated with complications like pneumonia and return to the operating room” [33, 34]. Few high-quality studies exist on the subject. The recent systematic review from the European Hernia Society (EHS) rehabilitation project found 889 studies on smoking’s effect on surgery outcomes but only selected three [30].

Smoking cessation might be one of the most frustrating endeavors for clinicians and patients. Centers for Disease Control and Prevention (CDC) states that nearly 70% of smokers want to quit, and 50% have tried in the last year, but only 7.5% of smokers succeeded [35]. Smokers that relapse begin to doubt their resolve and avoid the matter altogether. Preparing the right mindset is paramount. First, patients should be advised that smoking addiction is a chemical dependence issue. Then, it is essential to underline that few smokers succeed on their own, which is normal. The evaluation of nicotine dependence, as calculated by the Fagerström scale, might be an essential tool to understand the degree of investment and difficulty in the cessation attempt [36]. While a patient with low dependence and a regular inguinal or primary ventral hernia might be well off with basic counseling in the surgical consultation, average to high dependence patients will need specialized care and follow-up. The probability of success increases with a structured strategy that includes behavioral changes, nicotine replacement and counseling. The focus should rely on the fact that, in some cases, smoking may be a more significant health problem than the hernia itself.

Although the authors advise smoking cessation and offer help, treatment for uncomplicated hernias is not withheld if patients do not quit. Smoking cessation is essential to minimize complications, especially wound morbidity and respiratory hazards in extensive surgeries, multiple comorbidity and frailty or complex hernia repair. Following previous recommendations, the authors advise at least 4 weeks of cessation in these patients and always refer to a specific smoking cessation consultation. The authors do not, at present, perform biochemical confirmation of smoking cessation.

5. Addressing frailty

There is no uniform definition for the concept of frailty. Nonetheless, most health professionals agree that frailty includes reduced physical capacity, impaired mobility and susceptibility to hazardous outcomes [37]. Walter Joseph and colleagues proposed a modified Frailty Index [mFI] based on the NSQIP database to classify frailty and predict poor outcomes in abdominal wall reconstruction (AWR). This index includes variables such as diabetes, functional status, congestive heart failure or cerebrovascular accident with neurologic deficit. The authors successfully linked mFI to mortality and morbidity, meaning that this tool can also identify patients more likely to benefit from preoperative conditioning or prehabilitation [38].

Frailty, although not uniquely a physical impairment condition, is susceptible to improvement from physiotherapy and nutritional intervention [39]. Santa Mina and colleagues have already demonstrated that literature favors whole-body prehabilitation programs leading to improved physical functions and reduced LOS and pain [5]. Professor Francesco Carli and colleagues stated, “When exercise is undertaken on a regular basis, the body becomes more efficient in its adaptation to the stress of exercise.” Combined interventions of structured physical activity and improved nutritional support prevent and treat frailty and sarcopenia [40, 41].

6. Psychological preparation of patients

Expectations matter. Psychological factors, of which expectations play an important role, can be decisive in determining surgery results. In a double-blind sham surgery involving the treatment of advanced Parkinson’s disease patients, the sham procedure obtained better results than the actual procedure, again showing that the placebo effect has a role in surgery too [42].

In surgery, patient expectations concerning results may need to be revised, particularly in complex surgeries. Incisional hernia repair may have up to 30% recurrence rates and a considerable incidence of complications. It is important to involve patients in the decision making to inform them as accurately as possible, engage them in the process and build the right expectations towards surgery. Patient expectations influence postoperative outcomes. Patient satisfaction depends on fulfilling preoperative expectations and not preoperative positive expectations [43]. Better doctor-patient communication could establish reasonable expectations, thus increasing patient satisfaction. Patient expectation management could lead to better outcomes than other measures, and it is remarkably cost-effective.

7. Implementing a prehabilitation clinic

Much of the existing literature on prehabilitation focused on cancer patients. However, many non-fit patients suffer from benign diseases, including hernia, and should be candidates for an effective improvement programme [44]. A “hernia optimization clinic” was shown to improve risk management and even increase operative yield by operating patients previously deemed inoperable. Furthermore, case discussion in a multidisciplinary team followed by a preconditioning programme could recompense the increased risk of complications associated with the presence of risk factors [9, 45].

Only a structured, documented and evidence-based programme can overcome speculative prehabilitation strategies. Prehabilitation is increasingly multimodal and involves a variety of professions, from physiotherapy to nutrition and psychological support. Patient-centered care in hernia surgery, similarly to cancer surgery, should be tailored to specific patient needs and referral to a speciality should reflect those needs. Also, implementing a prehabilitation programme should consider the circumstances in which the patient is included [46].

8. Conclusion

Prehabilitation has demonstrated clear benefits in some, but not all, surgeries. In colorectal cancer surgery, several recent RCTs proved the positive effect of multimodal interventions. In thoracic surgery for lung cancer, it also demonstrated a positive, however more heterogeneous, effect [47, 48]. The mechanism through which prehabilitation contributes to potential outcome improvement is very intuitive. Nonetheless, evidence of its actual efficacy is lacking in many areas, especially for benign conditions [30]. On the other hand, improving patient function before surgery serves not for the surgery alone. Weight management strategies like bariatric surgery in morbidly obese patients improve health outcomes and QoL in itself. Better diabetes control or smoking cessation not only allows for fewer SSIs but also contributes to patients’ overall health. Reverting frailty through exercise programs and nutritional support improves people’s lives. Mindfulness about expectations and their management and identification of psychological barriers or misconceptions might improve doctor-patient communication and contribute to increased patient satisfaction. The authors believe the implementation of a structured multimodal preoperative intervention is essential to improve hernia care outcomes in patients with identifiable risk factors and potentially complex hernias.

Acknowledgments

We want to thank Prof Dr. Nuno Figueiredo, Hospital Lusíadas Lisboa and Hospital Lusíadas Amadora for their invaluable support of the abdominal wall team and patient pathway. We also thank Dr. Patrícia Lages for her input and support. Their insights and expertise were instrumental in shaping this manuscript.

Conflict of interest

The authors declare no conflict of interest.

Acronyms and abbreviations

RCT	randomized control trial
BMI	body mass index
SSI	surgical-site infection
SSO	surgical-site occurrence
TSH	trocar site hernia
NSQIP	National Surgical Quality Improvement Project
EHS	European Hernia Society
CDC	Centers for Disease Control and Prevention
mFI	modified Frailty Index
AWR	abdominal wall reconstruction