Anatomia Cirúrgica da REGIÃO INGUINAL
A hérnia inguinal é uma condição comum que ocorre quando um órgão abdominal protraí através de uma fraqueza na parede abdominal na região abdominal. O orifício miopectineal é a principal área de fraqueza na parede abdominal onde a hérnia inguinal pode se desenvolver. O conhecimento da anatomia da parede abdominal é importante para entender a patofisiologia da hérnia inguinal e para ajudar no diagnóstico e tratamento dessa condição médica comum.
Femoral Hernia REPAIR
Femoral hernia is not as common as inguinal hernia. It is often associated with incarceration or strangulation, resulting in peritonitis and mortality.
ANATOMY
The pelvicrural interval (the opening from the abdomen to the thigh) is divided into two spaces: a lateral space, the lacuna musculosa, through which the iliopsoas muscles pass; and a medial space, the lacuna vasculosa, for the femoral vessels. The external iliac vessels run along the anterior surface of the iliopsoas muscle in the pelvis, pass between the iliopubic tract and Cooper’s ligament, and finally course beneath the inguinal ligament to become the femoral vessels. Where the external iliac vessels run down into the lacuna vasculosa, transversalis fascia covers the vessels to form the femoral sheath. It extends approximately 4 cm caudally and ends as the adventitia of the femoral vessels. The medial compartment of the femoral sheath is called the femoral canal, which is ordinarily less than 2 cm in diameter and contains lymphatic vessels and glands. The true opening of the femoral canal is a musculoaponeurotic ring, consisting of Cooper’s ligament inferiorly, the femoral vein laterally, and iliopubic tract superiorly and medially. In the past, the medial border of the femoral ring was for the lacunar ligament. The lacunar ligament is an attachment of the inguinal ligament to the pubic bone, however, and lies in the outer layer of the transversalis fascia.
McVay demonstrated that the medial boundary of the femoral ring is the lateral edge of the aponeurosis of the insertion of the transversus abdominis muscle with transversalis fascia onto the pectin of the pubis, not the lacunar ligament. Condon also demonstrated that the iliopubic tract bridges the femoral canal and then curves posteriorly and inferiorly, its fibers spreading fanwise to insert adjacent to Cooper’s ligament into a broad area of the superior ramus of the pubis. Thus, the true inner ring of the femoral canal is bounded by the iliopubic tract anteriorly and medially, and by Cooper’s ligament posteriorly. If a surgeon incises the inguinal ligament in a tightly incarcerated femoral hernia, he or she will find that the hernia cannot be reduced because of the more deeply placed ring. The distal orifice has a rigid boundary—surrounded by the lacunar ligament medially; the inguinal ligament superiorly; and the fascia of the pectineal muscle—and is usually less than 1 cm in diameter. The rigidity of these structures is the reason why strangulation often occurs in femoral hernias.
ETIOLOGY
Currently, the ‘‘acquired’’ theory is widely accepted; however, the true cause of femoral hernia is not known. McVay demonstrated that the width of the femoral ring, which is determined by the length of the fanwise insertion of the iliopubic tract to Cooper’ ligament, is the main etiologic factor of the femoral hernia. Considering that the femoral hernia is very rare in children and most common in elderly women, however, McVay’s concept cannot be the only reason for the occurrence of femoral hernia. Nyhus noted the presence of a relatively large femoral defect without an accompanying femoral hernia during the preperitoneal approach. This may be caused by the acquired weakness of the transversalis fascia and a consequent predisposition to the development of the femoral hernia.
INCIDENCE
The ratio of femoral hernia relative to all groin hernias is reported to be 2% to 8% in adults . Femoral hernias are very rare in children, and most commonly observed between the ages of 40 and 70. The peak distribution is in the 50s, with a slight decrease in the 60s and 70s. As for sex distribution, femoral hernia is 4 to 5 times more common in female than in male; however, there are some reports that it is more common in men than in women. A right-sided presentation is more common than left, but the reason is not known.
TREATMENT
Finally, femoral hernia is usually thought of as requiring emergency surgical treatment. Only 30% of our cases were treated as emergency operations, however, whereas 70% were elective. Unless patients complain of severe abdominal pain or ileus, surgeons need not perform emergency operations. In summary, the mesh plug hernia repair for femoral hernia has resulted in a reduced recurrence rate, shortened hospital stay, and a low rate of postoperative complications.
Recurrence after Repair of Incisional Hernia
The incidence of recurrence in incisional hernia prosthetic surgery is markedly lower than in direct plasties. Indeed after the autoplasties of the preprosthetic period, the recurrence rate ranged from 35% for ventral hernias. Chevrel and Flament, in 1990, reported on 1,033 patients who had undergone laparotomy. The recurrence rate at 10-year follow-up was 14–24% for patients treated without the use of prostheses but only 8.6% for those in whom a prosthesis was implanted. A similar incidence was reported by Chevrel in 1995: 18.3% recurrence without prostheses, 5.5% with prostheses. Likewise, Wantz, in 1991, noted a recurrence rate of 0–18.5% in prosthetic laparo-alloplasties.
At the European Hernia Society (EHS)-GREPA meeting in 1986, the recurrence rate without prostheses was reported to be between 7.2 and 17% whereas in patients who had been treated with a prosthesis the recurrence was between 1 and 5.8%. A case study published by Flament in 1999 showed a 5.6% recurrence rate for operations with prostheses placed behind the muscles and in front of the fascia, and a 3.6% of such figure consisted of a small-sized lateroprosthetic recurrence. These rates were in contrast to the 26.8% recurrence reported by other surgeons for operations without prostheses.
Studies of recurrence are, of course, influenced by the size of the initial defect and the length of follow-up. Nevertheless, it is beyond dispute that the use of prostheses is associated with a lower rate of recurrence independent of the nature of the incisional hernia. The factors that lead to relapse are recognisable in the original features of the ventral hernia, i.e. combined musculo-aponeurotic parietal involvement, septic complications in the first operation, the nature and appropriateness of treatment, the kind of prosthesis and its position. Also important is whether the surgery was an emergency case and the relation to occlusive phenomena, visceral damage
and whether these problems were addressed at the same time.
Obesity is also an important risk factor for recurrence. In addition to its association with a higher surgical complications rate, related to the high intraabdominal pressure, there are deficits in wound cicatrisation as well as respiratory and metabolic pathologies. In such patients, the laparoscopic approach is very useful to significantly reduce the onset of general and wall complications, and the data concerning recurrence are encouraging, ranging between 1 and 9% in the largest laparoscopic case studies. The important multicentric study of Heniford et al., in 2000, reported a recurrence rate of 3.4% after 23 months. In 2003, the same author, in a study with an average follow-up of 20 months (range 1–96) showed a recurrence rate of 4.7% for different, identifiable causes: intestinal iatrogenic injuries and mesh infection with its removal, insufficient fixation of the prosthesis and abdominal trauma in the first postoperative period.
The incidence of recurrence after laparoscopic treatment may also be related to general patient factors and to the onset of local complications, mistakes in opting for laparoscopic treatment and deficits in implanting and fixing the prosthesis. With respect to the latter, it is very important to allow a large overlap compared to the diameter of the defect. Long-term data analysis, with large case studies, is still needed to obtain detailed information about recurrence, and this is particularly true in the assessment of relatively new techniques.
Strangulation in GROIN HERNIAS
Importance
Declining Mortality Rates
In both the UK and the USA, the annual death rate due to inguinal and femoral hernias has significantly decreased over the past two to three decades. In the UK, deaths from these hernias declined by 22% to 55% between 1975 and 1990. Similarly, in the USA, the annual deaths per 100,000 population for patients with hernia and intestinal obstruction decreased from 5.1 in 1968 to 3.0 in 1988. For patients with obstructed inguinal hernias, 88% underwent surgery, with a remarkably low mortality rate of 0.05%. These improvements suggest that elective groin hernia surgery has played a crucial role in reducing overall mortality rates.
Elective Surgery and Strangulation Rates
Supporting this observation, the USA has lower rates of strangulation compared to the UK, possibly due to the threefold higher rate of elective hernia surgeries in the USA. Nevertheless, statistics indicate that the rate of elective hernia surgeries in the USA per 100,000 population decreased from 358 to 220 between 1975 and 1990, although this may be an artifact of data collection rather than a genuine decline.
Mortality Analysis from UK and Denmark Studies
During 1991–1992, the UK National Confidential Enquiry Into Perioperative Deaths investigated 210 deaths following inguinal hernia repair and 120 deaths following femoral hernia repair. This inquiry, which focuses on the quality of surgery, anesthesia, and perioperative care, found that many patients were elderly (45 were aged 80–89 years) and significantly infirm; 24 were ASA grade III and 21 ASA grade IV. The majority of postoperative mortality was attributed to preexisting cardiorespiratory issues.
A nationwide study in Denmark of 158 patients who died after acute groin hernia repair by Kjaergaard et al. also found that these patients were old (median age 83 years) and frail (>80% with significant comorbidity), with frequent delays in diagnosis and treatment. These findings highlight the need for high-quality care by experienced surgeons and anesthetists, especially for patients with high ASA grades.
Postoperative Care Recommendations
Postoperative care for these patients should occur in a high-dependency unit or intensive therapy unit. This might necessitate transferring selected patients to appropriate hospitals and facilities. Decisions about interventional surgery should be made in consultation with the relatives of extremely elderly, frail, or moribund patients, adopting a humane approach that may rule out surgery.
Emergency Admissions and Prioritization
Forty percent of patients with femoral hernias are admitted as emergency cases with strangulation or incarceration, while only 3% of patients with direct inguinal hernias present with strangulation. This disparity has implications for prioritizing patients on waiting lists when these hernias present electively in outpatient clinics.
Risk of Strangulation
A groin hernia is at its greatest risk of strangulation within three months of onset. For inguinal hernias, the cumulative probability of strangulation is 2.8% at three months after presentation, rising to 4.5% after two years. The risk is much higher for femoral hernias, with a 22% probability of strangulation at three months, rising to 45% at 21 months. Right-sided hernias have a higher strangulation rate than left-sided hernias, potentially due to anatomical differences in mesenteric attachment. The decline in hernia-related mortality in both the UK and USA underscores the importance of elective hernia surgery. Ensuring timely surgery, especially for high-risk femoral hernias, and providing high-quality perioperative care for elderly and frail patients are crucial steps in further reducing mortality and improving patient outcomes.
Evidence-Based Medicine
In a randomized trial, evaluating an expectative approach to minimally symptomatic inguinal hernias, Fitzgibbons et al. in the group of patients randomized to watchful waiting found a risk of an acute hernia episode of 1.8 in 1,000 patient years. In another trial, O’Dwyer and colleagues, randomizing patients with painless inguinal hernias to observation or operation, found two acute episodes in 80 patients randomized to observation. In both studies, a large percentage of patients randomized to nonoperative care were eventually operated due to symptoms. Neuhauser, who studied a population in Columbia where elective herniorrhaphy was virtually unobtainable, found an annual rate of strangulation of 0.29% for inguinal hernias.
Management of Strangulation
The diagnosis of hernias is primarily based on clinical symptoms and signs, supplemented by imaging studies when necessary. Pain at the hernia site is a constant symptom. In cases of obstruction with intestinal strangulation, patients may present with colicky abdominal pain, distension, vomiting, and constipation. Physical examination may reveal signs of dehydration, with or without central nervous system depression, especially in elderly patients with uremia, along with abdominal signs of intestinal obstruction.
Femoral hernias can be easily missed, particularly in obese women, making a thorough physical examination essential for an accurate diagnosis. However, physical examination alone is often insufficient to confirm the presence of a strangulated femoral hernia versus lymphadenopathy or a lymph node abscess. In such cases, urgent radiographic studies, such as ultrasound or CT scan, may be necessary.
The choice of incision depends on the type of hernia if the diagnosis is clear. When there is doubt, a half Pfannenstiel incision, 2 cm above the pubic ramus extending laterally, provides adequate access to all types of femoral or inguinal hernias. The fundus of the hernia sac is exposed, and an incision is made to assess the viability of its contents. If nonviability is detected, the transverse incision should be converted into a laparotomy incision, followed by the release of the constricting hernia ring, reduction of the sac’s contents, resection, and reanastomosis. Precautions must be taken to avoid contamination of the general peritoneal cavity by gangrenous bowel or intestinal contents.
In most cases, once the constriction of the hernia ring is released, circulation to the intestine is restored, and viability returns. The intestine that initially appears dusky or non-peristaltic may regain color with a short period of warming with damp packs. If viability is doubtful, resection should be performed. Resection rates are highest for femoral or recurrent inguinal hernias and lowest for simple inguinal hernias. Other organs, such as the bladder or omentum, should be resected as needed.
After peritoneal lavage and formal closure of the laparotomy incision, specific repair of the hernia should be performed. Prosthetic mesh should not be used in a contaminated operative field due to the high risk of wound infection. Hernia repair should follow the general principles of elective hernia repair. It is important to remember that in this predominantly frail and elderly patient group with a high postoperative mortality risk, the primary objective of the operation is to stop the vicious cycle of strangulation, with hernia repair being a secondary objective.
Key Point
The risk of an acute groin hernia episode is of particular relevance, when discussing indication for operation of painless or minimally symptomatic hernias. A sensible approach in groin hernias would be, in accordance with the guidelines from the European Hernia Society to advise a male patient, that the risk of an acute operation, with an easily reducible (“disappears when lying down”) inguinal hernia with little or no symptoms, is low and that the indication for operation in this instance is not absolute, but also inform, that usually the hernia after some time will cause symptoms, eventually leading to an operation. In contrast, female patients with a groin hernia, due to the high frequency of femoral hernias and a relatively high risk of acute hernia episodes, should usually be recommended an operation.
How to Choose a Mesh in Hernia Repair
Since the introduction of polypropylene (PP) mesh for hernia repair, surgeons continue to discuss the use of mesh in a variety of settings for one of the most common operations performed by general surgeons—hernia repair. This discussion has involved raw materials, cost, and outcomes and for many years referred to only a few products, as manufacturing was limited. Nowadays, with multiple permanent, absorbable, biologic, and hybrid products on the market, the choice of mesh for a hernia repair can be daunting. Increasing clinical complexity further emphasizes the need for individualizing care, but more frequently, hospital supply chain personnel institute product procurement procedures for cost control, limiting mesh choice for surgeons. This can force surgeons into a “one-size-fits-all” practice regarding mesh choice, which may not be ideal for some patients. Conversely, current literature lacks definitive evidence supporting the use of one mesh over another, a fact that has not escaped the radar screen of the hospital supply chain and mesh industry, both of which attempt to limit vendor and mesh choice for financial gain. It is unlikely that this type of “proof” will ever come to fruition. This leaves us with choosing a mesh based on an algorithm that is centered on the patient and the patient’s unique clinical scenario.
Article: Mesh in Hernia Repair
Abdominal Hernia Surgical EMERGENCIES
A hernia is a weakness or disruption of the fibromuscular tissues through which an internal organ (or part of the organ) protrudes or slides through. Collectively, inguinal and femoral hernias are often lumped together into groin hernias. Surgery remains the only effective treatment, but the optimal timing and method of repair remain controversial. Although strangulation rates of 3% at 3 months have been reported by some investigators, the largest prospective randomized trial of (watchful waiting) men with minimally symptomatic inguinal hernias showed that watchful waiting is safe. Frequency of strangulation was only 2.4% in patients followed up for as long as 11.5 years. Long-term follow-up shows that more than two-thirds of men using a strategy of watchful waiting cross over to surgical repair, with pain being the most common reasons. This risk of crossover is higher in patients older than 65 years. Once an inguinal hernia becomes symptomatic, surgical repair is clearly indicated. Femoral hernias are more likely to present with strangulation and require emergency surgery and are thus repaired even when asymptomatic. Because this article focuses on incarcerated hernias, nonoperative options are not discussed.
The SURGEON 