Retroperitoneal abscess is a separate cavity in the retroperitoneal space filled with purulent exudate. Manifestations depend on the localization and prevalence of the pathological process. Common signs are malaise, nausea, fever. There are pains on the side of the purulent lesion with irradiation into the spine, shoulder blade, hip joint. Diagnosis is based on examination data, radiography of the abdominal cavity, ultrasound and CT of the retroperitoneal space. Combined treatment: percutaneous or surgical drainage of the abscess, antibiotic therapy.
Retroperitoneal abscess is a limited accumulation of pus located between the posterior leaf of the peritoneum and the intraperitoneal fascia. Ulcers can be single, while reaching significant volumes, or multiple. The diagnosis of the latter causes difficulties due to the small size of the formations and the erased clinical picture. Abscesses can form as a result of injuries, operations, perforation of a hollow organ, metastasis of infection from neighboring structures. After planned abdominal operations, ulcers occur in 0.8% of cases, after emergency operations – in 1.5%. The disease occurs mainly in people aged 20-40 years.
Causes of retroperitoneal abscess
The pathogenic flora involved in the formation of the purulent process is represented by anaerobic and aerobic bacteria (Staphylococcus, streptococcus, E. coli, clostridia, etc.). Factors contributing to the formation of an abscess can be divided into 2 groups:
- Primary. Open wounds of the abdominal cavity with contamination and insufficient surgical treatment of the wound lead to the formation of a limited pyogenic cavity. Closed injuries accompanied by damage to the retroperitoneal part of the intestine can contribute to the development of a purulent process and the formation of an abscess.
- Secondary. They occur due to hematogenic or lymphogenic (in 70% of cases) spread of infection from nearby organs. Retroperitoneal abscess can occur due to purulent pancreatitis, paranephritis, lymphadenitis, kidney abscess. The formation of a pyogenic cavity can be a complication of operations on retroperitoneal organs (ureter, duodenum, colon, etc.). In this case, the infection develops with insufficient sanitation of the purulent focus, violation of the rules of asepsis and antiseptics, irrational AB therapy and improper care in the postoperative period.
Depending on the location of the purulent process in the retroperitoneal space , abdominal surgery is distinguished:
1. Abscesses of the anterior retroperitoneal space. Located between the parietal peritoneum and the prefrontal fascia. These include:
- Pancreatic abscesses. They are formed as a result of destructive pancreatitis, pancreatic necrosis.
- Perinatal abscesses. They are formed during perforation of the duodenum 12, ascending and descending parts of the colon as a result of ulcers, wounds or tumors. An abscess is formed with a retroperitoneal arrangement of the vermiform process and the flow of pus into the paracolon (paracolon) with peritonitis.
2. Abscesses of the posterior retroperitoneal space. They are located between the anterior renal fascia and the transverse fascia lining the posterior part of the abdominal cavity. Include:
- Abscesses of the amniotic space. They are located on both sides between the anterior and posterior leaves of the renal fascia. They are formed with injuries of paranephron (perinephrine tissue), breakthrough of kidney ulcers (pionephrosis), with destructive retrocecally located appendicitis.
- Subdiaphragmatic abscesses. They are formed directly in the fiber under the diaphragm. Negative pressure under the dome of the diaphragm creates a suction effect and contributes to the accumulation of purulent contents under the diaphragm during perforation of appendicitis, spilled peritonitis, open and closed wound of the abdominal cavity.
Separately, psoas can be distinguished-an abscess formed with limited purulent inflammation of the lumbar muscle. The formation of a pyogenic cavity occurs due to hematogenic transmission of infection with osteomyelitis of the spine. Ulcers can reach large sizes and cause melting of the muscle.
Symptoms of retroperitoneal abscess
The clinical picture of the disease depends on the size and localization of the abscess, the duration of inflammation and the etiology of the pathological process. At the beginning of the disease, with small abscess sizes, symptoms may be absent. As the pyogenic formation increases, the symptoms of intoxication increase: chills, fever, malaise, nausea. The nature of the pain is due to the localization of the inflammatory process and is mainly of a diffuse nature. Painful sensations often occur in the side on the side of the lesion. Pain can radiate to the shoulder blade, thoracic spine, buttock and rectal area, hip joint.
Unpleasant sensations occur first during movement (when walking, trying to sit down, stand up, turn over on your side), and then at rest. With retroperitoneal abscesses of the anterior part, a rounded formation of the abdomen is sometimes palpated. With amniotic ulcers, pain is given to the back, spine and increases when trying to bend the leg in the hip joint. There is a violation of urination (dysuria). The prolonged nature of the disease leads to atrophy of the muscles of the lumbar and gluteal regions. Patients develop scoliosis, contracture and internal rotation of the hip on the side of the abscess.
A prolonged course of retroperitoneal abscess can lead to a breakthrough of the abscess into the pleural and abdominal cavity. This contributes to the development of pleural empyema and diffuse purulent peritonitis. The generalization of the purulent process with the occurrence of sepsis poses a threat to the patient’s life. Mortality in retroperitoneal abscesses varies from 10 to 30%.
The diagnosis of retroperitoneal abscess is carried out by an abdominal surgeon, which causes significant difficulties due to the lack of a clearly defined localization of pain and specific signs of the disease. Under the assumption of the presence of a limited purulent formation of the retroperitoneal region , the following examinations are carried out:
- Examination of the surgeon. The specialist will conduct a thorough physical examination, collecting anamnesis of life. Of great importance is the presence of concomitant somatic pathology and surgical interventions in the past. If a purulent process is suspected in the retroperitoneal cavity, the doctor prescribes an additional examination.
- Abdominal ultrasound. It detects inflammatory processes in the pancreas, kidneys, retroperitoneal tissue, fluid in the abdominal cavity. With a large abscess size, it is possible to visualize it as a rounded hypoechoic shadow.
- Abdominal x-ray. Allows you to detect a rounded formation with a liquid level.
- CT of retroperitoneal space. It is the most modern and effective method of research. Allows you to determine the location, size of the abscess and identify the cause of its formation.
- Laboratory tests. The blood test determines the signs of bacterial infection (leukocytosis, increased ESR, shift of the leukocyte formula to the left). When the pancreas is affected, the level of enzymes (amylase, lipase) in the biochemical analysis of blood increases. In diseases of the urinary system, leukocyturia, pyuria are noted. To identify the pathogen, a blood or urine test is performed for sterility.
Localization of retroperitoneal abscess is important for differential diagnosis. The initial stages of the disease are similar to the course of infectious diseases of various etiologies (typhoid fever, influenza, malaria). With an abscess of the anterior retroperitoneal space, differential diagnosis is carried out with pancreonecrosis, acute pancreatitis, peptic ulcer of the 12th duodenum. Amniotic abscesses should be distinguished from paranenephritis, acute pyelonephritis.
Treatment of retroperitoneal abscess
Treatment tactics depend on the size and location of the abscess. With small single abscesses, percutaneous drainage and the introduction of antibacterial drugs into the cavity using a catheter are carried out. Manipulation is performed under the control of ultrasound or CT. With incomplete emptying of the pyogenic cavity, a relapse of the disease is possible. With multiple, large single abscesses, surgical intervention is indicated. The operation consists in opening, draining the abscess, sanitizing the focus of inflammation and revision of the retroperitoneal space. The choice of access depends on the location of the abscess.
Amniotic abscesses are opened by posterolateral or posteromedial access. With indications for nephrectomy, the removal of the kidney is carried out in the second stage (after the relief of the purulent process). In subdiaphragmatic abscesses, extraperitoneal or transperitoneal access is used, in perinatal abscesses, anterolateral access is used. The opening of the psoas abscess is performed from an extraperitoneal access (an incision above the inguinal ligament along the crest of the ilium). With osteomyelitis of the iliac bone, sequestration is performed.
In case of retroperitoneal abscess of unspecified localization, the retroperitoneal space is opened with an oblique lumbar incision according to Pirogov, Israel, Shevkunenko. In all cases, before and after surgery, a course of antibiotic therapy is prescribed, taking into account the causative agent of the infection. After the operation, detoxification, anti-inflammatory and analgesic therapy is indicated.
Prognosis and prevention
The prognosis of the disease depends on the neglect of the purulent process, the general condition of the patient. With proper diagnosis and complex treatment of retroperitoneal abscess, the prognosis is favorable. When an abscess bursts, life-threatening conditions (sepsis, peritonitis) may occur. Prevention of the disease is aimed at rational treatment and postoperative management of patients with acute surgical pathology. Timely detection and drainage of the abscess plays an important role. Patients are recommended to consult a surgeon at the first symptoms of the disease.