Primary vs secondary iliopsoas abscess. Presentation, microbiology, and treatment

A simple scoring algorithm predicting paravertebral and/or iliopsoas abscess among adults with community-onset bloodstream infections: matters of PVL-producing Staphylococcus aureus

PURPOSE

Misdiagnosis or delayed diagnosis of paravertebral and/or iliopsoas abscess (PVIPA) has been frequently reported to be associated with unfavorable prognosis. We aimed to develop a scoring algorithm that can easily and accurately identify patients at greater risk for PVIPA among individuals with community-onset bloodstream infections.

METHODS

In a multicenter, retrospective cohort study, the score was developed with the first four study years and validated with the remaining two years. Applying logistic regression, the score values of prediction determinants were derived from the adjusted odds ratios (AOR). The performance of the scoring algorithm was assessed with the receiver operating characteristic (ROC) curve.

RESULTS

In the derivation (3869 patients) and validation (1608) cohorts, patients with PVIPA accounted for 1.7% and 1.4%, respectively. In the derivation cohort, five independent predictors of PVIPA were recognized using multivariable analyses: time-to-defervescence > 5 days (AOR, 7.00; 2 points), Panton-Valentine Leukocidin (PVL)-producing Staphylococcus aureus (AOR, 5.98; 2 points), intravenous drug users (AOR, 2.60; 1 points), and comorbid hemato-oncology (AOR, 0.41; -1 point) or liver cirrhosis (AOR, 2.56; 1 points). In the derivation and validation cohorts, areas under ROC curves (95% confidence intervals) of the prediction algorithm are 0.83 (0.77-0.88) and 0.85 (0.80-0.90), and a cutoff score of + 2 represents sensitivity of 83.3% and 95.7%, specificity of 68.6% and 67.7%, positive predictive values of 4.4% and 4.1%, and negative predictive values of 99.6% and 99.9%, respectively.

CONCLUSIONS

Of a scoring algorithm with substantial sensitivity and specificity in predicting PVIPA, PVL-producing S. aureus and Time-to-defervescence > 5 days were crucial determinants.

Iliopsoas Abscess Related to Pseudomonas aeruginosa: A Case Report

We describe a rare case of an 80-year-old male with an iliopsoas abscess (IPA) associated with Pseudomonas aeruginosa (P. aeruginosa). The patient had a history of diabetes mellitus and was admitted to our hospital due to aspiration pneumonia, where he was treated with ampicillin/sulbactam (ABPC/SBT). After admission, he experienced a recurrence of aspiration pneumonia, and ABPC/SBT was repeatedly used. The fever resolved by day 30 and antibiotic therapy was completed on day 33. Although the patient remained afebrile thereafter, anorexia persisted. On day 57, the patient experienced chills, fever, lower back pain, and bowel incontinence, leading to the resumption of ABPC/SBT at 6 g/day. Blood tests on day 59 showed elevated lactate dehydrogenase (239 IU/L) and C-reactive protein (15.08 mg/dL), along with decreased red blood cell count, hemoglobin, and albumin. An abdominal CT scan on day 60 indicated a low-density area suggestive of an abscess in the right iliopsoas muscle, and blood cultures from day 57 were positive for P. aeruginosa, prompting a switch to meropenem (MEPM) at 3 g/day. On day 61, lumbar MRI indicated hyperintensity at the L2/3 disc and vertebral bodies, suggestive of discitis and vertebral osteomyelitis. The antibiotic regimen was then changed to ciprofloxacin (CPFX) at 800 mg/day on day 62. Despite ongoing treatment, the patient's fever persisted, and percutaneous and surgical drainage were deemed unfeasible due to the abscess's size and location. The patient experienced a recurrence of pneumonia, leading to a switch to cefepime (CFPM) at 2 g/day on day 86, followed by piperacillin/tazobactam (PIPC/TAZ) at 13.5 g/day on day 96. Due to the deterioration of his clinical condition, he was transferred to a chronic care facility for palliative management on day 102 of hospitalization. Reports of IPA related to P. aeruginosa are very limited. In our case, the patient experienced recurrent pneumonia following hospitalization, and P. aeruginosa was isolated from the blood, suggesting that the lungs were the portal of entry, potentially leading to IPA as a result of the bloodstream infection. In cases involving the combination of P. aeruginosa and IPA, various compromised host factors, along with P. aeruginosa itself, may contribute to adverse outcomes. This report may enhance our understanding of the relationship between IPA and P. aeruginosa infections. Further accumulation of case reports and studies is necessary to better understand future treatment strategies and prognosis for IPA related to P. aeruginosa.

Silent Shadows: Unveiling the Psoas Abscess and Its Treatment

Iliopsoas abscesses are a rare complication of appendicitis and are associated with high morbidity and mortality without appropriate intervention. Current literature provides sufficient evidence for managing psoas abscesses via antimicrobial therapy, CT-guided percutaneous drainage, and laparoscopic or open drainage as primary approaches. However, there is insufficient data in the current literature for assessing improved patient outcomes with robotically assisted laparoscopic drainage as an approach to treatment. Here, we present the case of a 72-year-old male with a prior history of perforated appendicitis complicated by a pelvic abscess and treated interventional radiology (IR)-guided drain, left partial nephrectomy secondary to renal cell carcinoma, and bilateral hip arthroplasty presenting with signs and symptoms of recurrent appendicitis. CT imaging found a loculated right iliopsoas abscess adjacent to the appendix, which was not amenable to IR percutaneous drainage. Surgical drainage was deemed necessary with a robotically assisted approach, and the patient had improved clinical status after the intervention. Early results show that robotically assisted laparoscopic surgery has been shown to shorten the clinical course for patients via decreased length of stay, faster recovery times, and better incisions cosmetically. Drainage via robotic laparoscopy allows for complete drainage and irrigation, maximizing source control of infection. It is an effective approach for the management of refractory psoas abscesses secondary to appendicitis.

A case report of iliopsoas abscess and literature review

RATIONALE

Iliopsoas abscess is a rare acute medical condition. It usually occurs because of the spread of infection from adjacent structures and hematogenous spread. Clinical features include fever, backache, radiating nerve root pain, and leg weakness. When sepsis occurs, prompt recognition is required to initiate appropriate antimicrobial therapy and surgical drainage.

PATIENT CONCERNS

A 65-year-old male presented to the outpatient department with a 2-day history of lower back, hip, and leg pain, for which analgesics were administered. During hospitalization, he experienced deterioration, becoming febrile, hypoxic, hypotensive, tachycardiac, and delirious.

INTERVENTIONS

The patient was then intubated and ventilated. His family reported an additional history of acupuncture for back pain, which sustained an inflamed wound on his right forearm. Abdominal computed tomography was performed, which confirmed bilateral iliopsoas abscess without involvement of intra-abdominal organs. A preliminary report of blood culture revealed Gram-positive cocci. Echocardiography showed vegetation on the aortic valve, and moderate aortic regurgitation was sustained. He was started on vancomycin along with piperacillin-tazobactam. Ultrasound-guided percutaneous drainage was inserted into the bilateral abscess. Pus and blood yielded methicillin-sensitive Staphylococcus aureus. He remained septic. The repeat computed tomography showed the right abscess enlarged. A repeated echocardiogram showed that the vegetation increased. Further incision and surgical drainage were performed with continuous wash-out.

OUTCOME

His condition improved after management and he was discharged to a regional hospital for ongoing care.

CONCLUSION

Prompt diagnosis and surgical treatment are essential to improve patient outcomes. The unique aspect of this case is the persistence of the methicillin-sensitive Staphylococcus aureus infection. Centralized surgical services are pivotal in conjunction with robust antimicrobial regimens.

LESSON

This case reinforces the importance of high clinical suspicion of an unknown source of sepsis.

Psoas abscess: an uncommon disorder

BACKGROUND

Psoas abscess (PA) is an uncommon disease that has been increasingly reported in the recent years. We reviewed patients with PA and analyzed their clinical characteristics to improve our understanding of this rare disorder.

METHODS

We retrospectively reviewed the clinical presentations, microbiology, and outcomes of patients with PA between 2011 and 2022 at the Zhejiang Provincial People's Hospital in China.

RESULTS

There were 40 adult patients identified with the discharge diagnosis of PA. The mean age was 60 years, and 67.5% of the patients were male. Primary symptoms were typically nonspecific. In all, 20 abscesses were considered secondary, and the most common was infective spondylitis. The most common causative organism for primary PA was Staphylococcus aureus, followed by Escherichia coli, whereas multiple bacterial species were found in secondary abscesses. The overall in-hospital mortality rate was 5%. Patients with secondary PA had a longer hospital stay.

CONCLUSION

PA, as a serious infectious condition, usually presents with nonspecific symptoms and laboratory test results, making early diagnosis difficult. These profiles differed from those reported in the present study. The initial clinical status and subsequent imaging studies can lead to favorable outcomes.

Delayed iliopsoas abscess following COVID-19 pneumonia

Bacterial co-infection has been reported to contribute to a poor prognosis in patients with COVID-19. However, iliopsoas abscess (IPA) has not been previously reported as a comorbidity during the course of COVID-19. We report two cases of IPA in patients with COVID-19 pneumonia. Both patients required prolonged immunosuppressive therapy for COVID-19 pneumonia and developed bacteremia due to Serratia marcescens in one and Staphylococcus aureus in the other. Although immunosuppressive therapy is commonly used for COVID-19 pneumonia with hypoxemia, the comorbidity of IPA may have been underestimated in these cases.

Hounsfield Units as an Independent Predictor of Failed Percutaneous Drainage of Spinal Tuberculosis Paraspinal Abscess Under Computed Tomography Guidance

OBJECTIVE

To investigate the value of Hounsfield units (HUs) as an independent predictor of failed percutaneous drainage of spinal tuberculosis paraspinal abscess under computed tomography (CT) guidance.

METHODS

A retrospective analysis was conducted on 61 patients who underwent CT-guided percutaneous drainage for spinal tuberculosis paraspinal abscess between October 2017 and October 2020. Preoperative CT scans were used to measure the HUs of the abscess. Patients were categorized into successful drainage (n = 49) and failed drainage (n = 12) groups. Statistical analysis involved independent sample t-tests and chi-square tests to compare between the 2 groups. Binary logistic regression was performed to identify independent predictive factors for drainage failure. Receiver operating characteristic (ROC) curves were employed to ascertain risk factor thresholds and diagnostic performance.

RESULTS

Among the patients, 49 experienced successful drainage while 12 faced drainage failure. The mean HUs of abscesses in the failed drainage group were significantly higher than those in the successful drainage group (p < 0.001). ROC analysis revealed an area under the curve of 0.897 (95% confidence interval, 0.808-0.986) for predicting drainage failure based on HUs. The optimal HU cutoff value for predicting drainage failure was 22.3, with a sensitivity of 91.7% and specificity of 69.4%.

CONCLUSION

HUs are an independent predictor of failed percutaneous drainage of spinal tuberculosis paraspinal abscess under CT guidance. The HU value of 22.3 can be used as an initial screening threshold for predicting the success or failure of drainage.

Iliopsoas Hematoma Progression to Abscess in the Setting of Diabetic Ketoacidosis

Iliopsoas hematomas (IPH) are defined as a spontaneous or traumatic retroperitoneal collection of blood involving the iliopsoas muscle. In some cases, intramuscular hematomas can progress to abscesses and put the patient at risk for further complications. Our objectives are: to describe the etiology of intramuscular hematoma and psoas abscess, to describe the clinical signs and treatment of intramuscular hematoma and psoas abscess, and to analyze the association between uncontrolled diabetes mellitus and psoas abscess progression, which we achieve through retrospective case analysis and associated literature review on symptom constellation. We present the case of a 40-year-old male patient with a history of diabetes mellitus and alcohol abuse who presented with three days of increasing back and left lower extremity pain, confusion, auditory hallucinations, and fever found to be in diabetic ketoacidosis. Six days prior, the patient presented to the Emergency Department (ED) after being struck by a motor vehicle while ambulating found to have bruising, weakness in his lower extremities, and an L2 vertebrae fracture found on CT. During the presentation, the patient was found to have decreased muscle strength, leukocytosis with elevated lactate, and CT findings suggestive of a left psoas abscess drained by interventional radiology. Vancomycin and Cefepime were used as an empiric antibiotic regimen. The culture of the wound was then found to grow Methicillin-susceptible Staphylococcus aureus (MSSA) bacteria and antibiotics were then adjusted to Vancomycin and Cefazolin. During the patient's hospital stay, he developed two more abscesses on his bilateral psoas muscles, which were promptly percutaneously drained by interventional radiology. This case describes an uncommon progression of an Iliopsoas hematoma to a psoas abscess, likely due to his immunocompromised status secondary to his uncontrolled diabetes mellitus. Uncontrolled diabetes mellitus has been shown in various studies to be an independent risk factor of intramuscular hematoma progress to psoas abscess. We suggest that patients displaying fever, chills, flank pain, limited hip movement, and indications of uncontrolled diabetes should be approached with a high degree of suspicion for a psoas abscess.

Clinical Characteristics and In-Hospital Outcomes in Patients with Iliopsoas Abscess: A Multicenter Study

(1) Background: Iliopsoas abscess (IPA) is usually overlooked due to its nonspecific symptoms and signs. The resulting delayed diagnosis and treatment can increase morbidity and mortality. The purpose of the present study was to identify the risk factors for the unfavorable outcomes associated with IPA. (2) Methods: We included patients who presented to the emergency department and were diagnosed with IPA. The primary outcome was in-hospital mortality. Variables were compared, and the associated factors were examined with Cox proportional hazards model. (3) Results: Of the 176 patients enrolled, IPA was of primary origin in 50 patients (28.4%) and of secondary origin in 126 (71.6%). Skeletal origin was the most common source of secondary IPA (n = 92, 52.3%). The most common pathogens were Gram-positive cocci. Eighty-eight (50%) patients underwent percutaneous drainage, 32 (18.2%) patients underwent surgical debridement, and 56 (31.8%) patients received antibiotics. Multivariate analyses indicated that age > 65 (year) (HR = 5.12; CI 1.03-25.53; p = 0.046), congestive heart failure (HR = 5.13; CI 1.29-20.45; p = 0.021), and platelet < 150 (103/μL) (HR = 9.26; CI 2.59-33.09; p = 0.001) were significant independent predictors of in-hospital mortality in Model A, while the predictors in Model B included age > 65 (year) (HR = 5.12; CI 1.03-25.53; p = 0.046) and septic shock (HR = 61.90; CI 7.37-519.46; p < 0.001). (4) Conclusions: IPA is a medical emergency. Our study reported that patients with advanced age, congestive heart failure, thrombocytopenia, or septic shock had a significantly higher risk of mortality, and the recognition of the associated factors may aid in risk stratification and the determination of the optimal treatment plan for IPA patients.

A missed psoas abscess diagnosis: A forensic case report

Psoas abscess is a rare pathology that usually presents with non-specific signs and rare clinical features. These characteristics can delay the diagnosis leading to complications and death. We report a forensic autopsy case of a 65-year-old male, alcoholic, smoker, with a history of hypertension, and urinary infection, who presented to the emergency room for anorexia and consciousness disorder. On physical examination, the patient was febrile and confused. Laboratory exams revealed leukocytosis and elevated C-reactive protein (CRP). Two days later, he died despite extensive resuscitation. Forensic autopsy revealed a large amount of green pus in the left psoas muscle extending to the muscles of the thigh of the same side with multiple cavities. The pus extended to the left kidney with destructive parenchyma and coralliform lithiasis. Histological examination showed destroyed renal tissue by lesions of chronic and acute pyelonephritis with dilatation of the pyelocaliceal cavities. Bacteriological analysis of the pus showed the presence of Escherichia coli. The psoas abscess was secondary to pyonephrosis favored by the immunodeficiency. Thus, death was attributed to a septic shock secondary to a psoas abscess complicating pyonephrosis.

Primary Psoas Abscess in a Pediatric Patient: A Case Report

A psoas abscess is described as a collection of pus in the iliopsoas muscle compartment, which comprises the psoas and iliacus muscles located in the extraperitoneal space. It can be considered a primary abscess due to hematogenous or lymphatic seeding from a distant site, primarily occurring in children in tropical or developing countries. These primary infections are typically due to a single microorganism, most commonly, Staphylococcus aureus. Secondary spread develops due to the direct spread of infection of the psoas muscle from an adjacent structure (hip, vertebrae, gastrointestinal tract, aorta, genitourinary tract), developing due to trauma or instrumentation of the inguinal region, lumbar spine, or hip region. The secondary infections can be either mono- or polymicrobial and include enteric and anaerobic organisms. We present a case of psoas abscess in a five-year-old female who presented with a progressively worsening pain in the right hip for three days with refusal to bear weight and no history of trauma. Hip x-ray imaging yielded no abnormal results, but laboratory values prompted further investigation, leading to identifying a right psoas abscess via MRI with surrounding edema and enhancement. Imaging modality choice has proven to be instrumental in identifying psoas abscess and is key to achieving a diagnosis.

A case report of minimally invasive percutaneous ultrasound guided tuberculous iliopsoas abscess drainage in an immunocompromised patient

Introduction and importance

Iliopsoas abscess is a collection of pus that presents with nonspecific features with often delays in diagnosis however cause significant morbidity and mortality with Mycobacterium tuberculosis to be considered as causative agent in at risk individuals in tuberculous endemic regions. Management involves drainage and initiation of adequate antibiotics with radiological guided percutaneous approach considered the appropriate initial approach.

Case presentation

50-year-old immunosuppressed presenting with left iliopsoas abscess who underwent ultrasound guided drainage and placement of pigtail catheter successfully without the need for open surgical drainage. Our experience of interventional radiology for diagnosis of causative agent and treatment in a sub-Saharan Africa.

Clinical discussion

We concur with the recommendation to analyse fluid for tuberculosis in at risk individuals with minimally invasive procedures via interventional radiology as an adequate first line diagnostic and treatment option of psoas abscess. Ultrasound guided catheter placement and drainage successfully drained the abscess by day 10 similarly seen as the average duration in a case series from India.

Conclusion

The importance of the role of interventional radiology in treatment for complex abdominal pathologies in sub-Saharan Africa with its ability to diagnose and treat via minimally invasive procedures at highest precision and lowest risks and complications while maintaining a high level of suspicion for tuberculosis as the underlying etiology is highlighted.

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Minimally invasive procedure for drainage of a tuberculous iliopsoas abscess

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Image guided diagnosis and therapy

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Interventional radiology experience in sub-Saharan Africa

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Level of suspicion of tuberculous iliopsoas abscess in at risk individuals

Enterocutaneous Fistula and Pneumoretroperitoneum due to Ruptured Psoas Abscess

Psoas abscess is a rare condition that can present with vague clinical features. Its insidious onset can lead to a delay in diagnosis, resulting in high rates of complications and mortality. Here we describe a unique case of a patient presenting with enterocutaneous fistula and pneumoretroperitoneum due to ruptured psoas abscess.

Bilateral iliopsoas abscess presenting with abdominal wall cellulitis and left-sided empyema thoracis: a rare presentation

Iliopsoas abscess is common in immunocompromised patients and rarely presents with empyema thoracis. We present a 26-year-old male with no comorbidities who presented with a 3-day history of abdominal pain, fever and dyspnoea. There was no history of tuberculosis or recent contact with a tuberculous patient. On examination, the patient had facial dysmorphism and abdominal wall cellulitis extending bilaterally from flank to the inguinoscrotal region. Chest X-ray showed a left pleural effusion. Ultrasonography and contrast-enhanced CT also showed bilateral iliopsoas abscess with a left massive pleural empyema. The patient underwent bilateral abscess open drainage, thoracostomy for left empyema thoracis and intravenous antibiotic therapy. The patient had an uneventful course postoperatively and was discharged.

Six-stage revision surgery of a triple periprosthetic joint infection due to a delayed diagnosis of a bilateral psoas abscess: a case report

CASE

We present a case of a 70-year-old woman with simultaneous periprosthetic joint infection (PJI) of both hips and left knee due to a bilateral psoas abscess. The patient underwent debridement and implants removal with the consequent reimplantation in a sequential six-stage revision surgery. At four years of follow-up and in spite of the patient's comorbidities and current PJI presentation, she maintains full activities of daily living without restrictions.

CONCLUSION

Accurate and early diagnosis of a psoas abscess is crucial. This case report provides experience of a complex scenario, the decision-making involved and the outcomes of an underdiagnosed complication.

Pyogenic psoas abscess on the dorsal side, and bacterial meningitis and spinal epidural abscess on the ventral side, both of which were induced by spontaneous discitis in a patient with diabetes mellitus: A case report

Type 2 diabetes mellitus patients are immunocompromised, particularly under poorly controlled conditions, and thereby they could develop rare inflammatory diseases, such as spontaneous discitis, pyogenic psoas abscess, spinal epidural abscess and bacterial meningitis. Herein we report a pyogenic psoas abscess on the dorsal side, and bacterial meningitis and spinal epidural abscess on the ventral side, both of which were induced by spontaneous discitis in a patient with poorly controlled type 2 diabetes mellitus. This case was very rare and interesting, because we successfully treated various infections with antibiotics over a long period of time, complicated by hyperglycemic crises, although the patient suffered severe bone destruction and required rehabilitation for a long time.

Development of an Iliacus Muscle Abscess after School Exercise in a 17-Year-Old Female Student

Primary psoas abscess is due largely to hematogenous or lymphatic spread under immunocompromised conditions, whereas secondary psoas abscess is due largely to direct spread from adjacent infected structures. Trauma or hematoma within the muscle may predispose to the development of a primary abscess, especially if infection is present prior to injury, despite the absence of previous signs or symptoms of infection. This report describes a 17-year-old female high school student who developed an abscess within her iliacus muscle due to methicillin-susceptible <i>Staphylococcus aureus</i> after running 3 km on a hill as a school exercise. She was positive for antinuclear antibody and had had atopic dermatitis, suggesting that these factors, as well as exercise-related minor trauma or hematoma within the muscle, may have predisposed to abscess formation. She was treated with appropriate antibiotics and surgical drainage, resulting in recovery after 4 weeks.

Gas-Forming Psoas Abscess Secondary to Lumbar Spondylodiscitis

Lower back pain is a common presentation in clinical practice. Although most are musculoskeletal in nature, occult spine infection such as spondylodiscitis is commonly missed due to its insidious onset and non-specific symptoms. We report a case of a 63-year-old diabetic woman who presented to our institution's emergency department with altered mental status, nausea, and vomiting. She had a fall one month prior with persistent lower back-pain of increasing intensity. Initial laboratory data revealed an elevated leukocyte count with neutrophil predominance. Plain radiographs showed extensive gas shadows over the chest wall, abdomen, left thigh, and left knee. CT scan revealed L2 compression fracture with spondylodiscitis at L1/L2, left psoas abscess, and extensive subcutaneous emphysema. Open abscess drainage with extensive wound debridement was performed. Intra-operative pus, as well as blood cultures, yielded Escherichia coli. Unfortunately, the patient succumbed to the infection on the seventh day of admission secondary to multi-organ failure.

Magnetic Resonance Imaging, the Virtual Biopsy of Mesenteric Masses

ABSTRACT

The mesentery may be affected by multiple disease processes. Magnetic resonance imaging aids as a virtual pathological biopsy tool in the assessment of mesenteric masses because of superior soft tissue contrast and characterization. In this comprehensive review, we describe in detail the magnetic resonance imaging features of some solid and cystic mesenteric masses, with an emphasis on lesion-specific signal characteristics on T1- and T2-weighted images, diffusion-weighted imaging, and enhancement features on the dynamic postcontrast phase that aid in narrowing the differential diagnosis.

Epidemiological features and outcomes of patients with psoas abscess: A retrospective cohort study

Background

Psoas abscess (PA) is an uncommon disease. Although PA is associated with significant morbidity and mortality, its epidemiology and clinical characteristics remain unknown. This study aimed to evaluate the epidemiological and clinical features and outcomes of patients with PA in a prefectural-wide study.

Materials and methods

This was a multicenter retrospective cohort study conducted between 2010 and 2012 in the Miyagi prefecture with a population of 2,344,062 in 2011. Adult patients with PA were enrolled from 71 secondary and tertiary care hospitals.

Results

There were 57 patients with adult PA in the Miyagi prefecture. The median age of the patients was 72 years, and 67% patients were male. Fever and flank pain were the primary symptoms in 82% and 74% of patients, respectively. Ten patients (18%) had septic shock, and the hospital mortality rate was 12%. Secondary PA was present in 72% of cases, and the most common origin was pyogenic spondylitis. Of the patients with secondary PA, 44% had an epidural abscess. The most common pathogens were Staphylococcus aureus, and 11% (6 cases) of the cases were caused by methicillin-resistant S. aureus.

Conclusion

In the Miyagi prefecture of Japan, the estimated prevalence of PA was 1.21/100,000 population years and hospital mortality was 12%. Secondary PA accounted for more than 70% of the cases, and S. aureus was the most common causative pathogen.

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The hospital mortality rate of psoas abscess (PA) was 12% in Japan.

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Estimated prevalence of PA was 1.21/10,000 population years between 2010 and 2012.

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Secondary PA: >70% of cases with the most common origin as pyogenic spondylitis.

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Epidural abscess formed in 44% of patients.

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The most common pathogen was Staphylococcus aureus.

Retroperitoneoscopic Drainage of Psoas Abscess: A Systematic Review

BACKGROUND

Psoas abscess is a relatively rare clinical condition that can occur worldwide, is difficult to diagnose, and has a severe clinical course. Conventional treatment ranges from antibiotic therapy alone to computed tomography (CT)-guided and/or open surgical drainage. Retroperitoneoscopic drainage represents a minimally invasive and potentially definitive therapeutic option.

MATERIALS AND METHODS

A systematic review of the literature on minimally invasive extraperitoneal access for drainage of psoas abscess was conducted through PUBMED, EMBASE, and COCHRANE databases, according to the PRISMA statement guidelines. We considered only studies in English and with a full text. The quality of all selected articles was assessed for the risk of methodological bias. Additional literature sources were used to put into context the indications and limits of retroperitoneoscopic drainage.

RESULTS

Seven papers published between 2004 and 2020, including a total of 56 patients, met the eligibility criteria and were included in the qualitative analysis. Causative agents of psoas abscess included Mycobacterium tuberculosis, Klebsiella pneumoniae, Enterobacter aerogenes, Staphylococcus aureus, and Streptococcus spp. Tuberculous abscess was more common than pyogenic abscess (92.8% vs. 7.2%). Main clinical findings were back pain (76.8%) and fever (53.6%). All patients were preoperatively evaluated by CT or magnetic resonance imaging. Only 4 patients (7.1%) had previously undergone CT-guided percutaneous drainage. Retroperitoneoscopic drainage was combined with antibiotic therapy in all cases. No Clavien-Dindo grade >3 complications occurred, and there was no 30-day postoperative mortality. The recurrence rate was 1.8% at a mean follow-up of 21 months.

CONCLUSION

Retroperitoneoscopic surgical drainage is a safe and effective approach for the treatment of psoas abscess.

Psoas Abscess Caused by Candida Glabrata: A Case Report

Psoas abscess caused by Candida is an uncommon condition. We report a case of psoas abscess caused by Candida glabrata, which was completely resolved with drainage and oral voriconazole. Because of the nonspecific clinical presentation, the diagnosis of psoas abscess can be a challenge. Prompt suspicion, with early diagnosis and drainage with an appropriate antifungal agent, seems to improve the clinical outcome.

Delayed diagnosis and treatment of a psoas abscess as a link between spondylodiscitis and septic necrosis of the femoral head: a case report

Background:

Infections of the spine and hip joint are not common and, as described in literature, they are occasionally linked by a psoas abscess. In patients suffering back pain with history of spondylodiscitis, the spine as primary source of infection for a secondary psoas abscess should always be included in differential diagnosis. A delay in diagnosis of the psoas abscess could lead to septic femoral head necrosis.

Case report:

A case of a 65-year-old woman affected by septic femoral head necrosis due to spondylodiscitis and secondary psoas abscess is reported; the patient needed a specific antibiotic therapy then undergoing a total hip arthroplasty (THA).

Discussion and conclusion:

Diagnoses of lumbar spine infection and psoas abscess are difficult and often delayed. Since the symptoms of both are non-specific, high degree of suspicious is necessary. In psoas abscess, an early diagnosis is important, because a delayed treatment could result in septic femoral head necrosis requiring both a prolonged antibiotic therapy and a THA. (www.actabiomedica.it)

Laparoscopic drainage as a minimally invasive treatment for a psoas abscess: A single-center case series and literature review

A psoas abscess is a rare but potentially devastating condition that is associated with risks of neurological deficits, septic shock, and even death. The current first-line treatment is percutaneous catheter drainage (PCD) under imaging guidance, combined with broad-spectrum antibiotics. Surgical drainage should be considered if PCD fails or is impossible.Although many studies on PCD and open surgical drainage have appeared, the outcomes of laparoscopic drainage have rarely been reported. Thus, we laparoscopically drained the psoas abscesses of 6 patients; drainage was complete and we encountered no recurrence or complication. All patients were evaluated by plain radiography, contrast-enhanced computed tomography, and laboratory tests; all were followed-up for 1 year. Laparoscopic drainage is a good treatment option when PCD fails, affording all the advantages of open surgery (complete drainage, resection of infected tissue, and contermporaneous treatment of concomitant lesions). Also, laparoscopic drainage is minimally invasive, requires a smaller incision, and allows rapid recovery.

[Infectious myositis]

Infectious myositis is a rare condition that can be caused by bacteria, viruses, parasites or fungi. Muscle pain or weakness are symptoms shared by all type of myositis. Diagnosis is made on clinical presentation: fever and poor general state is found in bacterial myositis, diffuse muscle pain with flu-like symptoms in viral causes, eosinophilia and a tropical travel history can be related to parasitic etiology, and immunocompromising condition suggests fungal infection. Rhabdomyolysis, leukocytosis and elevated C-reactive protein are common. Imaging (computed tomography or magnetic resonance imaging) can be useful to detect which muscle is affected. The causative organism can be identified on blood cultures, skeletal muscle biopsy, serology or any other pathogen specific test. Treatment depends on the causative organism. Open surgical or imaging-guided drainage is usually necessary in bacterial myositis.

Primary iliopsoas abscess combined with rapid development of septic shock: Three case reports

RATIONALE

Primary iliopsoas abscess (IPA), an uncommon clinical entity, often has no specific clinical features, and advanced imaging techniques are often required for diagnosis.

PATIENT CONCERNS

We successfully treated 3 patients with primary IPA complicated by rapid development of septic shock within 2 months.

DIAGNOSIS

All patients were in shock at the time of admission and were diagnosed with primary IPA by history, clinical examination and imaging findings.

INTERVENTIONS

All patients were treated by surgical drainage and sensitive antibiotics based on culture results.

OUTCOMES

The patients eventually recovered and were discharged within 2 months.

LESSONS

An IPA may not be diagnosed in a timely manner because it has no specific symptoms or signs. Therefore, special attention must be given to patients with sudden onset of abdominal pain, hip pain, or high fever without an obvious cause, a primary IPA should be highly suspected in such patients.

Safe zone for irrigation and debridement of psoas abscess through a dorsal spinal approach

PURPOSE

This cadaver study was initiated to identify safe zones for psoas abscess debridement using a dorsal spinal approach.

METHODS

Twenty total specimens were dissected and lumbar transverse process (TP) and psoas muscles were identified. The distance from the lateral psoas muscle to the transverse process tip was measured. The lumbar plexus was dissected from the psoas and the distance from the TP to the lateral border of the lumbar plexus was measured. The area between the lateral edge of the psoas and lumbar plexus at each lumbar level was considered a safe zone of approach for entry into the psoas muscle for abscess debridement.

RESULTS

The most lateral portion of the lumbar plexus was 9.3 mm medial to the superior tip of the L1 TP and 9.2 mm medial to the inferior tip at L1, it was 11.8 and 11.7 mm medial at L2, 10.5 and 9.8 mm medial at L3, 6.6 and 6.2 mm medial at L4, and 1.0 and 0.9 mm medial at L5. The distances from the TP tip to the lateral edge of the psoas muscle were 5.7 and 5.5 mm medial to the superior and inferior tip of the TP at L1, 5.1 and 4.7 mm medial at L2, 2.5 and 1.8 mm medial at L3, 0.4 and 0 mm medial at L4 and 3.7 and 3.8 mm lateral at L5.

CONCLUSIONS

This study provides landmarks to avoid the critical structures in the lumbar spine.

Iliopsoas Abscess Presenting With Sacral Fracture and Gluteal Abscess: A Clinical Conundrum

Abscess of the iliopsoas muscle is a rare condition that requires a high degree of clinical suspicion for diagnosis. High mortality rates highlight the need for prompt recognition. We report the case of a 26-year-old man, with a history of intravenous drug use, who was referred from an outside facility with sacral fracture and gluteal abscess. Sacral trauma occurred 3 weeks before presentation, with progressive worsening of buttock pain. The patient was treated with irrigation and débridement of the gluteal abscess. Follow-up MRI revealed a communicating iliopsoas abscess that initially had been undiagnosed. After a prolonged hospital stay requiring additional irrigation and débridement procedures, the patient was discharged in a stable condition. Five-month follow-up has demonstrated no evidence of recurrence of infection. To our knowledge, this is the first reported case of Staphylococcus aureus gluteal abscess with pelvic extension into the iliopsoas secondary to sacral trauma and intravenous drug use.

Low Back Pain: Would it be Psoas Abscess?

Psoas abscess is an uncommon clinical entity. It can be a primary infection with no obvious source of infection or a secondary infection from other sites, e.g. gastrointestinal tract or spinal pathology. The triads of presentation: fever, loin pain and limitation of hip movement may not be found in all patients. The correct diagnosis can be made with a vigilant clinical examination and appropriate investigation, for example ultrasonography. We present two cases of psoas abscess. One was a primary case and the other was secondary to carcinoma of caecum. Both of them presented with recent onset of back pain. Emergency physicians consider psoas abscess as one of the differential diagnosis for patient complaining of low back pain.

Case of Psoas Abscess after Robotic-Assisted Laparoscopic Hysterectomy and Pelvic Lymphadenectomy

Iliopsoas abscess (IPA) is a rare condition seen in a variety of specialties that presents with nonspecific complaints. Presented herein is the development of an IPA after robotic staging with sentinel lymphadenectomy for endometrial carcinoma. The patient was a 61-year-old woman with history of prolonged immunosuppressive therapy due to psoriasis. She presented with an IPA 8 weeks after a robotic-assisted laparoscopic hysterectomy, bilateral salpingo-oophorectomy, and sentinel lymph node dissection. The patient was treated and cured with empiric antibiotics and drainage by interventional radiology. Although infrequent, one must keep IPA as a possible diagnosis in immunosuppressed patients who have undergone dissection of the retroperitoneal space during gynecologic surgery.

Psoas as an Unusual and Overlooked Place for a Metastatic Tumor

We report a case of a 60-year-old hemodialysis patient who clinically mimicked psoas abscess, which was subsequently proven to be from metastatic disease seconddary to uroepithelial tumor. The patient presented with 3 weeks history of fever, weight loss and back pain. Computer tomography (CT) scan of abdomen and pelvis revealed psoas muscle infiltration not amenable to drainage by interventional radiology. Careful history to provide additional clues to the diagnosis is of paramount importance in this condition.

Unusual presentations of Comamonas kerstersii infection

The association of Comamonas kerstersii with peritonitis resulting from the presence of perforated appendix has previously been described by our research team. In the present study, we describe the isolation of this microorganism from two forms of unusual presentations of C. kerstersii infection not previously described in the literature: localized intra-abdominal infection (psoas abscess) and pelvic peritonitis.

Urinary Obstruction of Transplanted Kidney Caused by Uterine Adenomyosis and 2-Year Posthysterectomy Psoas Abscess in Conjunction with Transplanted Kidney

Urinary obstruction of the transplanted kidney caused by uterine leiomyoma is an extremely rare condition. To the best of our knowledge, there are only two reports in English literature. Psoas abscess secondary to renal graft pyelonephritis is also uncommon. We present this unusual case and its treatment course. A 43-year-old female presented with renal dysfunction. She was started on peritoneal dialysis from the age of 26 years and received kidney transplantation from her mother (living donor) at the age of 27 years. Computed tomography (CT) revealed right hydronephrosis and a large uterine mass compressing the distal ureter of the transplanted kidney. After a simple total hysterectomy, her renal function improved. Two years following the hysterectomy, she experienced painful urination, fever, right abdominal pain, and right lower limb pain. CT and T2-weighed magnetic resonance imaging of her pelvis demonstrated right psoas abscess in conjunction with transplanted kidney. She was treated with broad-spectrum antibiotics alone, which resulted in a good response. Urinary obstruction of the transplanted kidney caused by uterine leiomyoma is an extremely rare condition. Psoas abscess secondary to transplanted kidney pyelonephritis is also rare. We should keep these rare diseases in mind when treating such cases.

Percutaneous drainage of psoas and iliopsoas muscle abscesses with a one-step technique under real-time computed tomography fluoroscopic guidance

PURPOSE

To evaluate the utility and safety of drainage catheter installation for psoas/iliopsoas muscle abscesses using a one-step technique under the guidance of real-time computed tomography (CT) fluoroscopy.

MATERIALS AND METHODS

Ten psoas or iliopsoas muscle abscesses in 7 patients that were treated with percutaneous drainage were included in this study. All drainage procedures were carried out using a one-step technique under real-time CT fluoroscopic guidance.

RESULTS

The drainage catheter insertion was performed successfully with the one-step technique in all lesions. Improvements in the patients' symptoms and blood test results were seen after the drainage procedure in all cases. In addition, postoperative CT scans demonstrated that the abscesses had reduced in size or disappeared in all but one patient, who was transferred to another institution while the drainage catheter was still in place. No major complications were seen in any case.

CONCLUSION

The one-step procedure is simple to perform. The percutaneous drainage of psoas or iliopsoas muscle abscesses with the one-step technique under real-time CT fluoroscopic guidance is accurate and safe. Moreover, compared with the two-step technique the one-step procedure results in a shorter drainage procedure and exposes the patient and operator to lower amounts of radiation. J. Med. Invest. 63: 323-327, August, 2016.

A Pain in the Psoas

General medical conditions are an important part of the differential diagnosis in athletes presenting with pain or injury. A psoas abscess is a collection of pus in the iliopsoas muscle compartment and is a rare cause of hip, low back, or groin pain. Psoas abscesses may have significant morbidity and mortality, as 20% progress to septic shock. Presenting symptoms are generally nonspecific and the onset may be subacute. Clinical presentation may have features suggestive of other diagnoses, including septic hip arthritis, iliopsoas bursitis, and retrocecal appendicitis. Proper diagnosis and management is critical to prevent complications of septic shock and death. In this unique case, a 19-year-old Division 1 collegiate football player presented to the emergency department 4 days following injury to his right groin during football practice. He complained of severe right groin pain accompanied by fatigue, fevers, nausea, and diarrhea. He later developed septic shock with multisystem organ dysfunction, requiring advanced life support. Imaging revealed an abscess located in the right iliopsoas compartment. After proper treatment, the athlete eventually made a complete recovery, returning to collegiate football 4 months postinjury. A literature review found no described cases of psoas abscess related to athletes with acute hip flexor strain. This athlete had no known risk factors for psoas abscess. This case highlights the importance of maintaining a broad differential in an athlete presenting with pain after injury. Making the diagnosis of psoas abscess often requires a high degree of suspicion and timely acquisition of imaging studies. In this particular case, imaging was key to making a proper diagnosis and tailoring treatment not only to return him to sport but also to save his life.

Psoas abscess secondary to retroperitoneal distant metastases from squamous cell carcinoma of the cervix with thrombosis of the inferior vena cava and duodenal infiltration treated by Whipple procedure: A case report and review of the literature

Background

Psoas abscess is a rare clinical disease of various origins. Most common causes include hematogenous spread of bacteria from a different primary source, spondylodiscitis or perforated intestinal organs. But rarely some abscesses are related to malignant metastatic disease.

Case presentation

In this case report we present the case of a patient with known squamous cell carcinoma of the cervix treated with radio-chemotherapy three years prior. She now presented with a psoas abscess and subsequent complete inferior vena cava thrombosis, as well as duodenal and vertebral infiltration. The abscess was drained over a prolonged period of time and later was found to be a complication caused by metastases of the cervical carcinoma. Due to the massive extent of the metastases a Whipple procedure was performed to successfully control the local progress of the metastasis.

Conclusion

As psoas abscess is an unspecific disease which presents with non-specific symptoms adequate therapy may be delayed due to lack of early diagnostic results. This case report highlights the difficulties of managing a malignant abscess and demonstrates some diagnostic pitfalls that might be encountered. It stresses the necessity of adequate diagnostics to initiate successful therapy. Reports on psoas abscesses that are related to cervix carcinoma are scarce, probably due to the rarity of this event, and are limited to very few case reports. We are the first to report a case in which an extensive and complex abdominal procedure was needed for local control to improve quality of life.

Iliopsoas Abscess Possibly due to Klebsiella pneumoniae Infection after Chemoradiotherapy for Hypopharyngeal Cancer

Iliopsoas abscess was once an uncommon condition but now occurs somewhat more frequently due to the increasing number of immunocompromised patients, such as those with diabetes. We encountered a case of iliopsoas abscess following chemoradiotherapy for hypopharyngeal cancer. A 60-year-old man was admitted for a sore throat and left neck swelling. Hypopharyngeal cancer was diagnosed, but the patient refused surgery. After two rounds of chemotherapy, febrile neutropenia developed and chest computed tomography (CT) revealed an iliopsoas abscess. The platelet count was low but recovered after administration of antibiotics and could not be explained by puncture of the abscess. CT-guided drainage eventually improved his symptoms. Even for disorders of the head and neck region, iliopsoas abscess should be suspected in immunocompromised patients who develop a fever. CT and magnetic resonance imaging should be performed at an early stage as it is important to determine whether surgical drainage is indicated.

Just another abdominal pain? Psoas abscess-like metastasis in large cell lung cancer with adrenal insufficiency

The authors report the case of a 69-year-old man with chronic obstructive pulmonary disease and previous pulmonary tuberculosis, who presented to the emergency department with abdominal and low back pain, anorexia and weight loss, rapidly evolving into shock. An initial CT scan revealed pulmonary condensation with associated cavitation and an iliopsoas mass suggestive of a psoas abscess. He was admitted in an intensive care unit unit; after a careful examination and laboratory assessment, the aetiology was yet undisclosed. MRI showed multiple retroperitoneal lymphadenopathies, bulky nodular adrenal lesions and bilateral iliac lytic lesions. Hypocortisolism was detected and treated with steroids. A CT-guided biopsy to the psoas mass and lytic lesions identified infiltration of non-small lung carcinoma. The patient died within days. Psoas metastases and adrenal insufficiency as initial manifestations of malignancy are rare and can be misdiagnosed, particularly in the absence of a known primary tumour.

Iliopsoas Abscess (together with Bullet) Resulting from a Firearms Injury

Psoas abscess, which is a rarely encountered infection, is defined as the accumulation of suppurative fluid within the fascia surrounding the psoas and iliac muscles. It is categorised as being primary or secondary. Although there are reports in the literature of secondary psoas abscess from foreign bodies, to the best of our knowledge, this is the first reported case of psoas abscess developing due to a bullet, following a firearms injury. The patient was first seen in the Emergency Department following a firearms injury in the posterolateral lumbar region and as the neurovascular examination was normal, the patient was discharged after 24 hours of observation. One month later, the patient presented again to the polyclinic with a high temperature and back pain. As a result of physical examination and tests, a diagnosis was made of psoas abscess and percutaneous drainage was applied under ultrasonography guidance. The complaints improved but, 10 days later with an increase in pain and indications of infection, open abscess drainage was applied and the bullet was removed. At the 6-month follow-up examination, the patient had no complaints.

'How to deal with this, that and the other?' An orthopaedic surgeon's unexpected encounter with a trio of problems in an elderly man

This is the first clinical report of a psoas abscess encountered during a routine hemiarthroplasty surgery for a femoral neck fracture in a man with a recent urinary tract infection. There were no prior symptoms to suggest a psoas abscess, which was present on the same side as the hip fracture, apart from a history of recurrent urinary tract infection. The surgery had to be altered intraoperatively to that of an excision arthroplasty of the displaced non-viable femoral head along with insertion of an antibiotic-impregnated cement spacer into the hip joint. Relevant microbiological studies confirmed a methicillin-sensitive Staphylococcus aureus psoas abscess with bacteraemia in addition to Staphylococcus bacteriuria, so 6 weeks of intravenous antibiotics were started. A planned second-stage hemiarthroplasty was undertaken and the patient recovered fully without complications. Primary infection of the urinary tract by S. aureus is rare. This case serves to remind clinicians that caution must be exercised in patients with recurrent infections, especially when such infections affect organs or areas close to the intended surgery site. This warrants thorough evaluation for an occult source of infection. A psoas abscess is an unusual cause of hip pain and accurate diagnosis relies on a high index of suspicion. The antibiotic-impregnated articulating cement spacer is a useful surgical adjunct after excision arthroplasty, it not only elutes a high concentration of antibiotics in the infected field, but also facilitates second-stage arthroplasty surgery by preventing muscle and soft tissue contractures from developing.

Features and treatment modality of iliopsoas abscess and its outcome: a 6-year hospital-based study

Background

Percutaneous drainage (PCD) and surgical intervention are two primary treatment options for iliopsoas abscess (IPA). However, there is currently no consensus on when to use PCD or surgical intervention, especially in patients with gas-forming IPA. This study compared the characteristics of patients with gas-forming and non-gas forming IPA and their mortality rates under different treatment modalities. An algorithm for selecting appropriate treatment for IPA patients is proposed based on our findings.

Methods

Eighty-eight IPA patients between July 2007 and February 2013 were enrolled in this retrospective study. Patients < 18 years of age or with an incomplete course of treatment were excluded. Demographic information, clinical characteristics, and outcomes of different treatment approaches were compared between gas-forming IPA and non-gas forming IPA patients.

Results

Among the 88 enrolled patients, 27 (31%) had gas-forming IPA and 61 (69%) had non-gas forming IPA. The overall intra-hospital mortality rate was 25%. The gas-forming IPA group had a higher intra-hospital mortality rate (12/27, 44.0%) than the non-gas forming IPA group (10/61, 16.4%) (P < 0.001). Only 2 of the 13 patients in the gas-forming IPA group initially accepting PCD had a good outcome (success rate = 15.4%). Three of the 11 IPA patients with failed initial PCD expired, and 8 of the 11 patients with failed initial PCD accepted salvage operation, of whom 5 survived. Seven of the 8 gas-forming IPA patients accepting primary surgical intervention survived (success rate = 87.5%). Only 1 of the 6 gas-forming IPA patients who accepted antibiotics alone, without PCD or surgical intervention, survived (success rate = 16.7%). In the non-gas forming IPA group, 23 of 61 patients initially accepted PCD, which was successful in 17 patients (73.9%). The success rate of PCD was much higher in the non-gas forming group than in the gas-forming group (P <0.01).

Conclusions

Based on the high failure rate of PCD and the high success rate of surgical intervention in our samples, we recommend early surgical intervention with appropriate antibiotic treatment for the patients with gas-forming IPA. Either PCD or primary surgical intervention is a suitable treatment for patients with non-gas forming IPA.

Candidal psoas abscess following persistent pyuria in a renal transplant recipient

Candidal infections occur commonly in renal transplant recipients especially in genitourinary system. Although the epidemiology of candiduria has not been well characterized in renal transplant population, it is the most common cause of fungal infections. However, candidal psoas abscess is very rare in the literature. We report a 42-year-old male renal transplant recipient with prolonged pyuria and candiduria followed by candidal psoas abscess formation. The treatment consisted of prolonged antifungal therapy along with percutaneous drainage. However, eventually, a surgical drainage had to be performed for the successful eradication.

Iliopsoas abscess--a review and update on the literature

Iliopsoas abscess is a rare condition with a varied symptomology and aetiology. Patients with this condition often present in different ways to different specialities leading to delays in diagnosis and management. Recent advances in the radiological diagnosis of this traditionally rare abscess have highlighted that there is a lack of evidence relating to its aetiology, symptomology, investigation and management. This article reviews the currently available literature to present a concise and systematic review of iliopsoas abscess.