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Retroperitoneal Fibrosis

Updated : January 12, 2024





Background

A chronic inflammatory & fibrotic process in the retroperitoneum known as retroperitoneal fibrosis (RPF) is a very uncommon disorder that can result in the compression of tissues within the retroperitoneum.

The inferior vena cava or other abdominal organs, such as the ureters, are frequently encased as a result of this fibrotic process. The process may be attributed to other reasons or idiopathic. Pharmacological intervention and surgical treatment are also possible forms of treatment.

Epidemiology

Patients with RPF are often between the years of 40 & 60. There is a male preponderance, with an estimated male-to-female of 2:1 or 3:1. Although the actual incidence is unknown, it is thought to be between 1 in 200,000 and 500,000 every year.

Anatomy

Pathophysiology

According to current theories, idiopathic retroperitoneal fibrosis is a symptom of a systemic immune disorder that may start as primary aortitis and result in a periaortic fibro-inflammatory reaction. Increased levels of autoantibodies, acute phase reactants, & established autoimmune disorders are frequently linked to the illness.

The idea that the condition is a primary systemic inflammatory illness of big arteries is supported by the fact that it also affects other vascular segments, including the mesenteric and thoracic arteries. The complex polymer of protein and oxidized lipids is known as ceroid, which is present in atherosclerotic plaques and is thought to be the antigen that sets off the inflammatory reaction. Histologically, macrophages, plasma cells, and B & T lymphocytes are all present. The majority of plasma cells are IgG4 (immunoglobulin 4 positive).

The existence of IgG4-producing plasma cells raises the possibility that RPF is a symptom of an IgG4-related illness (IgG4-RD). This multisystem disease is characterized by fibrosis of varying degrees, lymphoplasmacytic infiltration enriched in IgG4-positive plasma cells, and tumor-like enlargement of the affected organs. Uncertainty surrounds the precise pathophysiology of drug-induced RPF.

Etiology

Genetics

About 70% of retroperitoneal fibrosis cases are idiopathic. Idiopathic retroperitoneal fibrosis is regarded as a kind of chronic periaortitis, a vasculitis of the major vessels. It has been proposed that the complex polymer of oxidized proteins and lipids known as ceroid, which is frequently present in atherosclerotic plaques, functions as an antigen to trigger the inflammatory reaction.

Retroperitoneal fibrosis instances account for 30% of cases and have a known cause. RPF’s onset has been linked to a variety of medications. The most prevalent medications linked to this illness are ergot alkaloids like methysergide (Sansert) and others. Beta-blockers, Hydralazine, methyldopa, & analgesics are some additional drugs that have been linked.

Etanercept & infliximab, two biological medicines, have also been recognized as contributing factors. Secondary reasons for retroperitoneal fibrosis include surgery, retroperitoneal hemorrhage, radiation therapy for testicular seminomas, colon, & pancreatic carcinoma, infections (actinomycosis, TB, histoplasmosis), & malignancy (Hodgkin & non-Hodgkin lymphomas, sarcoma, carcinoid). According to studies, exposure to asbestos & tobacco smoke could raise the incidence of RPF.

Prognostic Factors

Frequently, the patient’s symptoms start to get better a few days after starting the medication. CT imaging may show that the mass has resolved within a few weeks.

The severity of the disease and the number of retroperitoneal structures entrapped determine whether all accompanying signs will completely resolve. Surgery can successfully remove the fibrotic tissue and safeguard the ureters if medicinal care is ineffective in curing the tumor.

Clinical History

Clinical History

retroperitoneal fibrosis is a rare disorder characterized by the abnormal growth of fibrous tissue in the retroperitoneum, which is the area behind the abdominal cavity that contains the kidneys, ureters, and other important structures. This fibrous tissue growth can lead to compression and obstruction of the affected organs, resulting in a range of symptoms.

The clinical presentation of RPF can vary widely depending on the extent of the fibrous tissue growth and the organs involved. Some common symptoms include:

Abdominal or back pain: This is often the first symptom of RPF, and it may be a dull ache or a more severe, stabbing pain. The pain may be constant or intermittent, and it may be exacerbated by movement or exertion.

Urinary symptoms: RPF can cause obstruction of the ureters, which are the tubes that connect the kidneys to the bladder. This can lead to urinary frequency, urgency, or difficulty urinating.

Kidney problems: In some cases, RPF can cause damage to the kidneys, leading to kidney failure. This may cause symptoms such as fatigue, swelling in the legs and ankles, and changes in urine output.

Other symptoms: RPF can also cause a range of other symptoms, such as weight loss, fever, night sweats, and malaise.

The diagnosis of RPF typically involves a combination of imaging studies, such as CT scans or MRIs, and laboratory tests to evaluate kidney function and rule out other conditions that may cause similar symptoms. Treatment may involve medications to reduce inflammation and relieve symptoms, as well as surgical intervention in more severe cases. Long-term monitoring and management of RPF are typically necessary to prevent complications and ensure optimal outcomes.

Physical Examination

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Differential Diagnosis

  • Retroperitoneal Lymphoma
  • Retroperitoneal Erdheim-Chester disease

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

Initial Management

The patient’s clinical condition will determine how RPF is initially managed. Patients who show signs of ureteral compression, hydronephrosis, and uremia require urgent decompression with an indwelling ureteral stent or a percutaneous nephrostomy tube. When RPF has created ureteral obstruction, placing a ureteral stent is typically not difficult. The ability to do retrograde pyelograms during the process to assess the anatomy is a benefit of ureteral stent implantation.

Nephrostomy tube implantation is preferred in critically ill individuals with electrolyte imbalances & minimal or even no urine production. The patient must be continuously watched for post-obstructive diuresis, kidney function condition, and the proper replenishment of electrolytes and fluids after renal decompression. After the urine system is completely unobstructed, a conspicuous polyuria known as post-obstructive diuresis develops (exceedingly more than 200 mL per hour).

Patients run the danger of developing hypovolemic shock, severe dehydration, & electrolyte abnormalities. Often, the situation only persists for up to 48 hours. Fluid replacement & thorough monitoring of blood BUN, electrolytes, and creatinine are also part of the treatment. Although oral replenishment is preferred, if the patient cannot be unable to accept oral liquids or cannot replace the fluid loss, half of the fluid loss is replaced with normal saline (500 mL for every 1 L lost). After the first handling, it’s important to determine the RPF’s possible causes. Any medicine that can cause an incident needs to be stopped right away.

Medical Treatment

The standard primary medical management after RPF has been diagnosed, whether through radiologic signs or biopsy proved, has been steroid medication. When RPF is treated with steroids alone, 80% of patients respond, according to scientific literature. This includes a quick drop in ESR, diuresis, and relief of pain & clinical signs within days of starting medication. While there are many variations in steroid dosages & duration, typical regimens begin with an initial dosage of 60 mg daily and are reduced to 5 mg once daily.

One professional agreement suggests administering 1 mg/kg of prednisone daily for around 4 weeks. The dose is decreased over weeks to 10 mg/day & maintained for a further 6 to 18 months if the improvement is seen. It has been demonstrated that long-term steroid treatment can significantly reduce clinical symptoms & reverse retroperitoneal bulk for up to two years. After four to six weeks of treatment, if no clinical & radiologic recovery is seen, a CT scan and a biopsy should be performed to confirm the identification of RPF.

Steroids can be combined with other medications if it is determined that RPF is the cause of the illness. Azathioprine, mycophenolate mofetil, methotrexate, cyclosporine, and cyclophosphamide are some of these medications. Progesterone, tamoxifen, & medroxyprogesterone acetate have also been discovered to be beneficial for the therapy of RPF. Although relapse rates during steroid tapering have been reported to be as high as 50%, the use of immunosuppressive medications should only be used after steroid treatment fails.

A patient’s response to therapy must be closely monitored. Within one month of starting treatment, the patient should undergo a clinical evaluation to see whether the urinary blockage and pain have been resolved. Following that, the patient should have clinical monitoring every two to three months. ESR, serum creatinine, CRP, & BUN should be measured monthly for the first three months and then every two to three months after that. To track the growth of the fibrotic mass, a CT scan should be taken one month after starting treatment and then roughly every three months after that.

It is advised to have a renal ultrasound, ESR, serum creatinine concentration, CRP, & a CT every six months for the first year after stopping medicinal treatment, followed by laboratory tests every six to twelve months and a CT every one to two years to check for disease return. Indefinitely should be spent on surveillance.

Surgical Treatment

The following situations are saved for surgical intervention:

  • Technological challenges or issues with further cystoscopic and endoscopic obstruction-relieving techniques.
  • Medical intervention fails to reduce the bulk, and the ureters, as well as other structures, continue to be encased.
  • Features that could point to underlying cancer in order to make a final diagnosis.

Surgery can be performed using an open, laparoscopic, and robotic method and involves ureterolysis & ureteral manipulation to stop recurring obstruction. The wrapping of the ureters in omental fat, which acts as a barrier to prevent encasement by fibrous tissue & encourages revascularization, transplanting the ureters into an intraperitoneal location, and transposing the ureters laterally with the interposition of retroperitoneal fat between the ureters & fibrous tissue are all techniques used to prevent recurrent ureteral obstruction.

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

Media Gallary

References

https://www.ncbi.nlm.nih.gov/books/NBK482409/

https://emedicine.medscape.com/article/458501-clinical

Retroperitoneal Fibrosis

Updated : January 12, 2024




A chronic inflammatory & fibrotic process in the retroperitoneum known as retroperitoneal fibrosis (RPF) is a very uncommon disorder that can result in the compression of tissues within the retroperitoneum.

The inferior vena cava or other abdominal organs, such as the ureters, are frequently encased as a result of this fibrotic process. The process may be attributed to other reasons or idiopathic. Pharmacological intervention and surgical treatment are also possible forms of treatment.

Patients with RPF are often between the years of 40 & 60. There is a male preponderance, with an estimated male-to-female of 2:1 or 3:1. Although the actual incidence is unknown, it is thought to be between 1 in 200,000 and 500,000 every year.

According to current theories, idiopathic retroperitoneal fibrosis is a symptom of a systemic immune disorder that may start as primary aortitis and result in a periaortic fibro-inflammatory reaction. Increased levels of autoantibodies, acute phase reactants, & established autoimmune disorders are frequently linked to the illness.

The idea that the condition is a primary systemic inflammatory illness of big arteries is supported by the fact that it also affects other vascular segments, including the mesenteric and thoracic arteries. The complex polymer of protein and oxidized lipids is known as ceroid, which is present in atherosclerotic plaques and is thought to be the antigen that sets off the inflammatory reaction. Histologically, macrophages, plasma cells, and B & T lymphocytes are all present. The majority of plasma cells are IgG4 (immunoglobulin 4 positive).

The existence of IgG4-producing plasma cells raises the possibility that RPF is a symptom of an IgG4-related illness (IgG4-RD). This multisystem disease is characterized by fibrosis of varying degrees, lymphoplasmacytic infiltration enriched in IgG4-positive plasma cells, and tumor-like enlargement of the affected organs. Uncertainty surrounds the precise pathophysiology of drug-induced RPF.

About 70% of retroperitoneal fibrosis cases are idiopathic. Idiopathic retroperitoneal fibrosis is regarded as a kind of chronic periaortitis, a vasculitis of the major vessels. It has been proposed that the complex polymer of oxidized proteins and lipids known as ceroid, which is frequently present in atherosclerotic plaques, functions as an antigen to trigger the inflammatory reaction.

Retroperitoneal fibrosis instances account for 30% of cases and have a known cause. RPF’s onset has been linked to a variety of medications. The most prevalent medications linked to this illness are ergot alkaloids like methysergide (Sansert) and others. Beta-blockers, Hydralazine, methyldopa, & analgesics are some additional drugs that have been linked.

Etanercept & infliximab, two biological medicines, have also been recognized as contributing factors. Secondary reasons for retroperitoneal fibrosis include surgery, retroperitoneal hemorrhage, radiation therapy for testicular seminomas, colon, & pancreatic carcinoma, infections (actinomycosis, TB, histoplasmosis), & malignancy (Hodgkin & non-Hodgkin lymphomas, sarcoma, carcinoid). According to studies, exposure to asbestos & tobacco smoke could raise the incidence of RPF.

Frequently, the patient’s symptoms start to get better a few days after starting the medication. CT imaging may show that the mass has resolved within a few weeks.

The severity of the disease and the number of retroperitoneal structures entrapped determine whether all accompanying signs will completely resolve. Surgery can successfully remove the fibrotic tissue and safeguard the ureters if medicinal care is ineffective in curing the tumor.

Clinical History

retroperitoneal fibrosis is a rare disorder characterized by the abnormal growth of fibrous tissue in the retroperitoneum, which is the area behind the abdominal cavity that contains the kidneys, ureters, and other important structures. This fibrous tissue growth can lead to compression and obstruction of the affected organs, resulting in a range of symptoms.

The clinical presentation of RPF can vary widely depending on the extent of the fibrous tissue growth and the organs involved. Some common symptoms include:

Abdominal or back pain: This is often the first symptom of RPF, and it may be a dull ache or a more severe, stabbing pain. The pain may be constant or intermittent, and it may be exacerbated by movement or exertion.

Urinary symptoms: RPF can cause obstruction of the ureters, which are the tubes that connect the kidneys to the bladder. This can lead to urinary frequency, urgency, or difficulty urinating.

Kidney problems: In some cases, RPF can cause damage to the kidneys, leading to kidney failure. This may cause symptoms such as fatigue, swelling in the legs and ankles, and changes in urine output.

Other symptoms: RPF can also cause a range of other symptoms, such as weight loss, fever, night sweats, and malaise.

The diagnosis of RPF typically involves a combination of imaging studies, such as CT scans or MRIs, and laboratory tests to evaluate kidney function and rule out other conditions that may cause similar symptoms. Treatment may involve medications to reduce inflammation and relieve symptoms, as well as surgical intervention in more severe cases. Long-term monitoring and management of RPF are typically necessary to prevent complications and ensure optimal outcomes.

Differential Diagnosis

  • Retroperitoneal Lymphoma
  • Retroperitoneal Erdheim-Chester disease

Initial Management

The patient’s clinical condition will determine how RPF is initially managed. Patients who show signs of ureteral compression, hydronephrosis, and uremia require urgent decompression with an indwelling ureteral stent or a percutaneous nephrostomy tube. When RPF has created ureteral obstruction, placing a ureteral stent is typically not difficult. The ability to do retrograde pyelograms during the process to assess the anatomy is a benefit of ureteral stent implantation.

Nephrostomy tube implantation is preferred in critically ill individuals with electrolyte imbalances & minimal or even no urine production. The patient must be continuously watched for post-obstructive diuresis, kidney function condition, and the proper replenishment of electrolytes and fluids after renal decompression. After the urine system is completely unobstructed, a conspicuous polyuria known as post-obstructive diuresis develops (exceedingly more than 200 mL per hour).

Patients run the danger of developing hypovolemic shock, severe dehydration, & electrolyte abnormalities. Often, the situation only persists for up to 48 hours. Fluid replacement & thorough monitoring of blood BUN, electrolytes, and creatinine are also part of the treatment. Although oral replenishment is preferred, if the patient cannot be unable to accept oral liquids or cannot replace the fluid loss, half of the fluid loss is replaced with normal saline (500 mL for every 1 L lost). After the first handling, it’s important to determine the RPF’s possible causes. Any medicine that can cause an incident needs to be stopped right away.

Medical Treatment

The standard primary medical management after RPF has been diagnosed, whether through radiologic signs or biopsy proved, has been steroid medication. When RPF is treated with steroids alone, 80% of patients respond, according to scientific literature. This includes a quick drop in ESR, diuresis, and relief of pain & clinical signs within days of starting medication. While there are many variations in steroid dosages & duration, typical regimens begin with an initial dosage of 60 mg daily and are reduced to 5 mg once daily.

One professional agreement suggests administering 1 mg/kg of prednisone daily for around 4 weeks. The dose is decreased over weeks to 10 mg/day & maintained for a further 6 to 18 months if the improvement is seen. It has been demonstrated that long-term steroid treatment can significantly reduce clinical symptoms & reverse retroperitoneal bulk for up to two years. After four to six weeks of treatment, if no clinical & radiologic recovery is seen, a CT scan and a biopsy should be performed to confirm the identification of RPF.

Steroids can be combined with other medications if it is determined that RPF is the cause of the illness. Azathioprine, mycophenolate mofetil, methotrexate, cyclosporine, and cyclophosphamide are some of these medications. Progesterone, tamoxifen, & medroxyprogesterone acetate have also been discovered to be beneficial for the therapy of RPF. Although relapse rates during steroid tapering have been reported to be as high as 50%, the use of immunosuppressive medications should only be used after steroid treatment fails.

A patient’s response to therapy must be closely monitored. Within one month of starting treatment, the patient should undergo a clinical evaluation to see whether the urinary blockage and pain have been resolved. Following that, the patient should have clinical monitoring every two to three months. ESR, serum creatinine, CRP, & BUN should be measured monthly for the first three months and then every two to three months after that. To track the growth of the fibrotic mass, a CT scan should be taken one month after starting treatment and then roughly every three months after that.

It is advised to have a renal ultrasound, ESR, serum creatinine concentration, CRP, & a CT every six months for the first year after stopping medicinal treatment, followed by laboratory tests every six to twelve months and a CT every one to two years to check for disease return. Indefinitely should be spent on surveillance.

Surgical Treatment

The following situations are saved for surgical intervention:

  • Technological challenges or issues with further cystoscopic and endoscopic obstruction-relieving techniques.
  • Medical intervention fails to reduce the bulk, and the ureters, as well as other structures, continue to be encased.
  • Features that could point to underlying cancer in order to make a final diagnosis.

Surgery can be performed using an open, laparoscopic, and robotic method and involves ureterolysis & ureteral manipulation to stop recurring obstruction. The wrapping of the ureters in omental fat, which acts as a barrier to prevent encasement by fibrous tissue & encourages revascularization, transplanting the ureters into an intraperitoneal location, and transposing the ureters laterally with the interposition of retroperitoneal fat between the ureters & fibrous tissue are all techniques used to prevent recurrent ureteral obstruction.

https://www.ncbi.nlm.nih.gov/books/NBK482409/

https://emedicine.medscape.com/article/458501-clinical