GUIDED PERCUTANEOUS BIOPSY OF RETROPERITONEAL LESIONS

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GUIDED PERCUTANEOUS BIOPSY OF RETROPERITONEAL
LESIONS
INTV11

• Medical Imaging Departement La Rabta Hospital

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INTRODUCTION

• Percutaneous fine-needle aspiration biopsy
  (PFNAB) under computed tomographic (CT) guidance
  has proved to be a widely accepted method of
  documenting malignancy.
• Refinements in technique, experience with the
  procedure, and improvements in CT scanners have
  permitted a high degree of accuracy.
• We present our experience over a 8-year period
  with this technique.

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OBJECTIVES

• The aim of this work is to present an overview of
  Indication of percutanous needle biopsy which
  include
• diagnosis of primary or metastatic malignacy in a
  newly discovered mass,
• diagnosis of tumor recurrence in patients known
  with malignancy
• diagnosis of infection and benign disease.

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PATIENTS AND METHODS

• we retrospectivly reviewed percutaneous
  retroperitoneal biopsies performed in 49 patients
  between 2008 and 2011.
• All biopsies were performed by the radiology
  staff in the imaging department La Rabta.
• Biopsies were performed under CT guidance
  helical CT (Tomoscan CX / S).

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PATIENTS AND METHODS

• The decision of the percutaneous biopsy was
  multidisciplinary, taking into account
• the report risk / benefit
• technical feasibility of the procedure.
• Patients were informed of the nature of the act
  and its possible risks and especially the
  importance of their cooperation.
• procedures were done under local anesthesia
• Hemostasis tests were performed before the
  procedure.

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RESULTS

• biopsy concerned renal masses in 12 cases
  revealing

Patients Histological type
5 Carcinoma
1 liposarcoma
3 lymphoma.
1 xanthogranulomatous pyelonephritis
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RESULTS

• In 8 of the 49 patients with retropenitoneal
  abnormalities, metastatic neoplasm was diagnosed,
  the primitive tumour was

cases organ
3 pancreas
2 kidney
1 lung
1 Urinary tract
1 Undetermined
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RESULTS

• Biopsy of a retro-peritoneal mass in 32 patients
  was

cases nature
17 Lymphoma
8 metastasis
4 Retroperitoneal fibrosis

• In two of five adrenal biopsy pulmonary
  metastasis was shown.

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RESULTS

• In 9 cases tissue obtained was inadequate for
  diagnosis
• insufficient sample in 4.
• hemorrhagic or necrotic in 2.
• normal parenchyma in 3.
• In two of five adrenal biopsy pulmonary
  metastasis was shown.

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By side biopsy of an unresectable medial renal
mass.
Biopsy of a left lower pole renal mass avoiding
the necrotic component.
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Biopsy of the hypodense right renal mass.
Confirmation of the diagnosis of lymphoma.
Trans-hepatic adrenal mass biopsy confirming its
metastatic origin in a patient with a primitive
lung.
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Discussion

• In our institution, most abdominal aspiration
  procedures during the past 9 years were performed
  under CT control.
• CT permits accurate placement of a needle tip
  into small lesions, and its proximity to major
  vessels is readily ascertained.
• The cross-sectional format of CT permits choice
  of the most appropriate needle approach to a
  suspected abnormality (i.e. , anterior,
  posterior, lateral, or oblique)
• The skin puncture site, needle path, and depth
  can be readily determined from hard copy images
  and the measured depth for sampling directly
  transposed to the needle with a sterile rule.

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DISCUSSION

• Problems related to patient size, bowel gas,
  dressings and patient positioning, can all be
  accommodated by the CT guidance procedure.
• As the contraindications to CT-guided biopsy
• the lack of patient cooperation,
• coagulation problems
• technical impossibility due to interruption by
  major vessels and bowel are noted.

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DISCUSSION

• CT-guided biopsy was not indicated in a case that
  the envisaged path direction was not considered
  to be safe due to interruption
• by major vessels,
• bowel and
• vertebral bodies
• enough specimens from the small lesions located
  at a deep site should be obtained with
  satisfactory sample for histological examination

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DISCUSSION

• There is a wide variety of needles from which to
  choose, with various needle gauges, tip
  configurations, and sampling mechanisms.
• For this discussion, they will be divided into
  three general groups
• small-gauge aspiration needles such as the
  Chiba cytology study
• small-guage cutting-core-biopsy needles
  difficult path or high hemorrhagic risk
• larger cutting needles such as the 18-gauge
  Menghini, 18-gauge Biopty, and 14-gauge TruCut.

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DISCUSSION

• Factors to consider when choosing a needle
  include
• location of the lesion,
• proximity to other structures,
• amount of tissue needed (pathologists needs),
• operator preference.
• Aspiration needles are designed to obtain
  cytologic samples only. Occasionally, they obtain
  small pieces of tissue, which can be processed
  for histologic examination.

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Guillotine needle type tru-cut chisel tip
mandrel bent and made
Guillotine needle with deployed stylet. (b) the
tissue core in biopsy needle.
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After skin marking the puncture site,
disinfection and local anesthesia, the first
needle carrier is introduced to the periphery of
the mass. (b) Performing the biopsy needle
through the mandrel.
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Discussion

• Before performing any biopsy, the previous
  diagnostic studies should be reviewed, and the
  clinical findings and information sought should
  be discussed with the referring physician in
  order to plan the most appropriate procedure.
• Review of the previous diagnostic studies is
  helpful in selecting the imaging technique,
  approach, and positioning of the patient for the
  biopsy.

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Discussion

• With CT guidance, most lesions are best
  approached by choosing a needle path that
  minimizes the skin-to-lesion distance.
• When this involves traversing bowel or other
  organs, and when an alternative route is
  available, the alternative route is often chosen
  to avoid these other structures.
• However, with thin-needle aspirations in the
  immunocompetent patient, it is possible to cross
  bowel, stomach, liver, or other structures
  without unacceptable risks

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Schematic representation of different possible
approaches and organs that can be climbed during
percutaneous gestures.
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Discussion

• For ease of performance, it is best if the needle
  path lies in the axial plane.
• This allows the entire needle to be visualized
  on a single image.
• However, other structures often surround the
  lesion and preclude such an approach.
• Several authors have described methods used to
  approach lesions that were not accessible via a
  direct approach.

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DISCUSSION

• otherwise inaccessible lesions cqn be approached
  
• either from above or below and using a geometric
  approach to calculate the needle angle (the
  so-called triangulation method), many ons can
  be sampled safely.
• This is especially valuable in
• renal,
• superior retroperitoneal
• adrenal lesions
• when avoiding the caudal extent of the pleura is
  important to diminish the risk of
• pneumothorax,
• pleural contamination,
• malignant seeding of the pleural space.

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DISCUSSION

• RENAL BIOPSY
• We can divide the indications for biopsy of renal
  masses in two groups
• Established indications for which there is a
  sufficient experience
• Emerging indications that the biopsy remains a
  topic of discussion and controversy

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DISCUSSION

• Established indications
• Atypical renal cell carcinoma it may be cystic
  lesion, with fatty component or a low vascular
  mass.
• An unresectable mass which malignancy is not
  established.
• Suspicion of lymphoma.
• The patient with high surgical risk.
• A mass, in which the infectious origin is
  suspected.
• Emerging indication
• Homogeneous, not cystic renal mass seen on
  ultrasound.
• A complex cystic mass
• Treatment by radiofrequency or cryo-ablation is
  discussed

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DISCUSSION

• ADRENAL BIOPSY
• This biopsy is associated with a high rate of
  complication and the negative predictive value
  (80).
• On the other hand negative biopsy does not
  allow to formally eliminate the possibility of a
  metastasis, or to differentiate between adenoma
  and adenocarcinoma.
• The current indications for adrenal biopsy are
• The indeterminate lesions discovered
  incidentally.
• A mass with a relative percentage of wash out
  upper or equal to 50.
• A benign-looking lesion but increased in size.

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DISCUSSION

• LYMH NODE BIOPSY
• Suspicion of lymphoma.
• Lymphoma and residual masses after treatment.
• The metastasis, Infectious or during a
  granulomatous lymph node.

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DISCUSSION

• BIOPSY OF RETROPERITONEAL LESIONS
• Depending on the size of the lesion and its
  location within the retroperitoneum,
• either an anterior or posterior approach can be
  used,
• although the posterior approach is usually
  preferred and is most often necessary to ensure a
  clear path for the use of cutting needles.

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CONCLUSION

• Guided percutaneous biopsy of abdominal lesions
  especially retroperitoneal lesions clearly has
  become an important diagnostic tool.
• The success of this technique lies in the
  accuracy that can be achieved as well as in its
  relative safety and ease of performance.