Ultrasound-guided Prostate Puncture

Sonographically guided prostate biopsy (synonyms: sonographically guided prostate puncture; ultrasound-guided prostate biopsy; ultrasound-guided prostate puncture) is a diagnostic procedure in urology that can be used, among other things, to detect and evaluate prostate cancer. The prostate biopsy (tissue removal from the prostate) is performed as a so-called systematic biopsy (SB) with the support of transrectal ultrasound (TRUS; transrectal/ultrasound examination of the prostate via the rectum) in B-scan mode (B-TRUS; echo signals are visualized as two-dimensional sectional images in gray scale). In this context, one speaks of a transrectal prostate biopsy (TR-PB). Transrectal prostate biopsy is considered the gold standard, i.e., a scientific procedure that represents the most proven and best solution in a given case. In addition to transrectal punch as a biopsy method, there is also transperineal punch/biopsy. In transperineal biopsy (synonym: perineal biopsy (pB)), this is performed by means of a thin needle inserted into the prostate through the skin of the perineum. Perineum refers to the perineum, which is the region between the anus and the external genital organs.The detection of prostate cancer is done by histological (fine tissue) examination of the prostate punch biopsies. A prostate biopsy is only performed if there are reasonable grounds for suspicion, such as abnormal palpation of the prostate, abnormal PSA values (prostate-specific antigen; tumor marker) or the appearance of suspicious changes in the prostate on transrectal ultrasound (TRUS).

For several years, magnetic resonance imaging (MRI) has also been used in the diagnosis of prostate cancer (MRI/TRUS fusion biopsy), but the cost of an MRI-based examination is significantly higher. Furthermore, targeted fusion biopsy by MpTRUS/mpMRI (multiparametric TRUS) is now available as an alternative to sonography-guided prostate biopsy. In this process, an MRI data set of the prostate is imported into the sonography (ultrasound), which can then be moved simultaneously with the real-time sonography after slice matching and coregistration. This is used for more targeted prostate biopsy.

Indications (areas of application)

In the context of early detection, prostate biopsy should be recommended in the presence of at least one of the following criteria:

  • Controlled PSA level of ≥ 4 ng/mL at the initial screening consultation, taking into account influencing factors; control of PSA levels should occur after six to eight weeks
  • Result suspicious for carcinoma on digital rectal examination (DRU; an examination of the rectum and adjacent organs by palpation performed with a finger)
  • Abnormal PSA increase (without changing the determination method) [PSA dynamic: threshold between 0.35 ng/ml year and 0.75 ng/ml per year].
  • Questionable local recurrence (again cancer cells at the site where it occurred the first time) after previous irradiation, e.g. PSA level increase after irradiation.
  • Patients in the “active surveillance protocol” (“active surveillance”) which prescribes repeat biopsies.
  • Patients in whom a previous biopsy requires a repeat biopsy e.g., high-grade intra-epithelial neoplasia (PIN), “atypical small acinar proliferation,” or suspicious but undiagnosed carcinoma
  • Positive protein pattern diagnostics (synonym: proteomic analysis) – positive results in protein pattern diagnostics from urine serve as further indications for biopsy.

In younger patients, a biopsy indication can be made individually even at lower PSA values.

Contraindications

Bleeding tendency – hemophilia (congenital bleeding tendency) requires special precautions to avoid serious complications.

Before prostate puncture

  • Anesthesia – depending on the patient’s wishes, the examination can be performed either with applied local anesthesia, general anesthesia, or analgesia (simultaneous analgesia/anesthesia and sedation). However, the health condition of the patient concerned must be taken into account when making the choice. General anesthesia represents a much greater effort for the body than local anesthesia (local anesthesia).
  • Antibiotics oral antibiotic therapy (fluoroquinolones: ciprofloxacin) should be given the day before and the day of the biopsy, with the first dose taken the evening before the biopsy. The more effective alternative to ciprofloxacin is fosfomycin–trometamol in terms of urinary tract infections (1.5% versus 12.9% with ciprofloxacin) and risk of sepsis (0.3 versus 1.8%. Note: A risk factor for severe infections appears to be fluoroquinolone-resistant bacteria in the stool.Note: Taking a rectal swab (rectal swab) before biopsy, making cultures, and targeting antibiotics according to culture results has more success than standard prophylaxis. Note: Ciprofloxacin, levofloxacin, moxifloxacin, norfloxacin and ofloxacin are not approved in Germany for prophylactic use during surgery or surgical procedures in the genitourinary system.
  • Anticoagulation – discontinuation of antithrombotics (anticoagulants) such as acetylsalicylic acid (ASA) or Marcumar should be done in consultation with the treating physician. A study on the risk of bleeding with continued anticoagulant therapy after transperineal prostate biopsy demonstrated that there was no increased risk of hemorrhage (bleeding risk) compared to the comparison group (not taking anticoagulants).Low-dose aspirin therapy should not be considered a contraindication.
  • Caveat. Caution should be exercised in patients on steroidal therapy, as this has been shown to be a risk factor for developing sepsis (blood poisoning).

The surgical procedure

With the help of sonographic diagnostics, there is the possibility of achieving a precise and reproducible representation of the prostate. At the same time, the volume of the gland can also be determined, which has an important meaning in urological diagnostics. Furthermore, sonography allows an accurate and targeted biopsy (tissue sampling) from the prostate for histological (fine tissue) or cytological examination. Decisive parameters for the assessment of whether a neoplasia (benign or malignant neoplasm of tissue) is present can be assessed in a prostate sonogram both by the symmetry of the prostate and by its capsular echoes and internal echostructure. With the help of these parameters, it is possible to check an existing palpation finding (palpation finding) and, if necessary, to refute it during a biopsy (tissue sampling). In addition, the visual markers can also be used to make a statement about the benignity or malignancy of a neoplasm in the gland. Among other things, inhomogeneous (non-uniform) structures serve as indications of a possibly malignant finding. This variation in the tissue is based on a different echo intensity compared to the surrounding tissue of the prostate. In general, suspicious structures have low-echo features and are often located in the upper part of the prostate. In addition, it can be determined that many neoplasms are located in or touching the capsule. Procedure

  • After analgesia is given, the patient is positioned in the lithotomy position so that the attending physician has easy access to the area under examination. Furthermore, intravenous access must be established for each prostate puncture so that, for example, a paracetamol short infusion can be applied if necessary.
  • Depending on the type of anesthesia, analgesia with three milligrams of midazolam (anesthetic) may be administered. Local infiltrative anesthesia (anesthetic) decreases the sensation of pain during the punch biopsy of the prostate. Ultrasound-guided periprostatic block is state-of-the-art. Alternatively, intrarectal installation of a local anesthetic (local anesthesia; administration of an anesthetic and disinfectant gel into the rectum) may be the only procedure. However, this is clearly inferior to the periprostatic injection.
  • Before prostate puncture can be performed, rectal digital palpation (palpation of the rectum) must first be performed, and then transrectal sonography of the prostate (transrectal prostate sonography) can be performed. In order to be able to use the optimal localization for the puncture, ultrasound-guided imaging of a puncture mark in cross-section and longitudinal section is performed. Then, during prostate puncture, the automatic biopsy needle is used to perform a puncture five times per side lobe, starting at the seminal vesicle angle and moving apically (located at the tip).Palpatory conspicuous areas can be additionally palpatory targeted biopsies.The current S3 guideline calls for the removal of 10 to 12 tissue cylinders and their separate submission.
  • Due to the fact that the majority of tumors are located near the capsule, it is necessary that an examination focus on the control of the tissue near the capsule.
  • After the procedure has been performed, the attending physician inserts a special insert of a gauze strip mixed with a mucosal anesthetic into the rectum (rectum) as a mucosal tamponade. After completion of the examination, an inspection of the patient’s urine and a residual urine control are indicated.

Note: mpMRI-guided and CUDI-guided (contrast ultrasound dispersion imaging (CUDI)) targeted prostate biopsies in the diagnosis of carcinoma are inferior to systematic twelve-punch biopsy (see above). This is true for both relevant and insignificant carcinomas.

After prostate puncture

  • The gauze strips mixed with the anesthetic usually come off spontaneously with the first bowel movement. If this is not the case, the gauze strips may be removed by gently pulling the gauze strip after two hours.
  • The patient should be instructed to take it easy and drink plenty of fluids.
  • Patients with indwelling transurethral catheters should be monitored closely for signs of urosepsis; the same applies to patients with diabetes mellitus.

Potential complications

  • Hemospermia (> 1 day; 6.5-74.4% of cases) – analogous to macrohematuria, the presence of bloody semen is also a mild complication that by no means requires further follow-up.
  • Macrohematuria (-14.5% of cases) – macrohematuria is the occurrence of visibly bloody urine. Microhematuria, on the other hand, is not visible to the naked eye and requires special diagnostic methods for detection. However, macrohematuria in the first days after surgery is considered a mild complication that does not require presentation to the attending physician.
  • Bloody stools (rectal bleeding > 2 days: 2.2% of cases) – Blood accumulation on the first stool is not a concern, but if it still occurs after a few days, a follow-up examination is necessary. If a larger amount of blood is excreted, then immediate re-presentation is unavoidable.
  • Prostatitis (prostatitis; 1.0% of cases).
  • Fever (> 38.5 °C; 0.8% of cases) – the occurrence of fever indicates infection in the wound area, so readmission should be immediate. If the diagnosis is confirmed, hospitalization is indicated (due torisk of sepsis (blood poisoning), up to four percent of patients).
  • Epididymitis (inflammation of the epididymis; 0.7% of cases).
  • Ischuria (urinary retention) (0.2% of cases).
  • Pain – pain may occur after the examination when the anesthesia wears off. However, if the pain is more severe, a physician should be consulted.

The “aftermath” of a biopsy, i.e., discomfort such as bleeding (80%) or pain (42.7%), lasted an average of 5.3 days, with the longest duration reported at 46 days.

Follow-up examinations, ie, rebiopsy

Rebiopsy within six months should be recommended for the following constellations of findings:

  • Extensive high-grade PIN (evidence in at least 4 tissue samples).
  • Atypical Small Acinar Proliferation (ASAP).
  • Suspicious PSA value or course.

In circa 20% of these cases, rebiopsy (re-tissue sampling) finds prostate cancer. “Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial”: men with elevated PSA (PSA > 4.0 ng / ml), whose biopsy is negative, rarely die of prostate cancer: in the nearly 13-year follow-up period, 1.1% of men after negative biopsy and 7.5% after positive biopsy died of prostate cancer (in the control group 0.4%). Additional notes

  • In patients with radical prostatectomy (surgical removal of the prostate with capsule, the terminals of the vas deferens, the seminal vesicles, and the regional lymph nodes) who previously had multiple biopsies (≥ 2) with the aid of transrectal sonography showed {13]:

    • A significantly lower continence rate (ability to retain urine) three months after surgery compared with patients who had tissue removal.
    • For erectile dysfunction (ED; erectile dysfunction), no difference between single and multiple biopsies (tissue removal).
  • Increasingly, perineal (“belonging to the perineum (perineum)”) biopsy (pB) is discussed as a suitable biopsy procedure. This is said to have the following advantages:
    • Re-admissions due to sepsis were significantly less often needed after transperineal biopsy (1.0% vs. 1.4%)
    • Wg. better detection of peripheral areas – compared to transrectal approach – carcinoma detection rate should be higher.

    Disadvantages:

    • After transperineal punching, men were more likely to need to spend the night as an inpatient than men after transrectal biopsy (12.3% vs. 2.4%)
    • After transperineal biopsy, men were more likely to require hospitalization for urinary retention