Ch 113 prostate

Question 1

anatomy

Answer 1

• bilobed structure that completely encircles the proximal urethra immediately caudal to the bladder
• endodermal origin and arises from the pelvic urethral epithelium
• composite collection of mesenchymal, urethral, and Wolffian duct tissue with glandular and nonglandular components bound within a common capsule.
• remains abdominal until the urachal vestige breaks down at 2 months of age, at which time it occupies a pelvic position
• At puberty the gland enlarges and migrates to occupy a partially abdominal position.
• adult life the gland continues to undergo hyperplastic enlargement and migrates further cranially
• prostatic arteries branch from the internal pudendal vessels
• significant anastomoses between the prostatic arteries and the urethral and cranial and caudal rectal arteries
• autonomic nerve supply to the gland is via the hypogastric and pelvic nerves

Question 2

What is the normal size of the prostate?
What breed can have a healthy larger prostate?

Answer 2

0.64-0.96g/kg
Scottish Terriers

Question 3

Is the prostate peritoneal or retroperitoneal?

Answer 3

Both! Its ventral aspect is retroperitoneal

Question 4

What nervous input increases glandular secretion?

Answer 4

Parasympathetic suppy from the pelvic nerve

Question 5

histology

Answer 5

• comprises secretory epithelial tissue contained within a stromal capsule of fibrous, elastic, and smooth muscle tissue.
• The epithelial tissue is subdivided into distinct lobules by smooth muscle septa
• characterized by compound tubuloalveolar glands,

Question 6

What are the 2 forms of acinar gland dilation seen within the mature prostate?

Answer 6

• Simple dilatation: Many dilated acini with or without luminal oesionphilic secretions which no not compress adjacent acini
• Focal glandular ectasia: Focal dilatation of a few acini with oesinophilic content and compression of the adjacent prostatic parenchyma

Question 7

List the functions of the prostatic secretions

Answer 7

• Promote spermatozoa motility and viability
• Increase uterine perfusion
• Modulate neutrophil-induced inhibition of spermatazoa attachment to uterine epithelium

Question 8

What substances are found within prostatic secretion

Answer 8

• High concentration of zinc and zinc-binding proteins
• Acid phosphatase (also produced by epididymis)
• Canine prostate-specific esterase (90% total protein)
• Large amounts of PGE2

Question 9

hormonal regulation

Answer 9

• continues to undergo progressive androgen-mediated enlargement throughout life as the consequence of benign prostatic hyperplastic changes
• 50% by 5 years and 70% by 8 to 9 years
• Two distinct forms of BPH glandular and complex, are recognized (glandular in younger dogs (<4 to 5 years), complex hyperplasia is the more common form after that age
• glandular form: confined to the secretory cells, which increase in number and size, giving rise to a symmetric enlargement. testosterone regulates gene expression in the nuclei to control prostatic growth
• increased responsiveness to androgens by the prostate as it ages
• changes of complex prostatic hyperplasia involve primarily the stromal elements69 and are characterized by an asymmetric enlargement
• Estrogens are thought to play a role in the pathogenesis of benign prostatic hyperplasia,

Question 10

Diagnostics

Answer 10

• Dogs with prostatic enlargement may have concurrent perineal hernias; thus pelvic diaphragm status should be evaluated
• transurethral washing, or aspiration of fine needle samples.
• gland is normally surrounded by periprostatic adipose tissue and hence appears to have a radiolucent margin that allows it to be distinguished

ultrasound
- BPH: increase in the overall gland size, a heterogenous increase in echodensity, and small focal areas of echolucency. Cystic changes are also common
- Abscessation appears as a progression of this, with highly characteristic hyperechoic capsular and loculated tissue
- Discrete prostatic cysts have a hyperechoic fluid ultrasound appearance

Question 11

What is glandular BPH?

Answer 11

• predominates in younger dogs
• Secretory cells increase in number and size leadng to symmetric enlargement
• Testosterone is metabolised by 5alpha-reductase in the prostate to 5alpha-dihydrotestosterone
• Regulates gene expression in the nuclei to control prostatic growth

Question 12

What is complex BPH?

Answer 12

Most common form, predominates in older dogs
As the prostate increases in size, 5alpha-dihydrotestosterone concentrations decrease
Paralleled by increase in metabolism of androgens within the prostate and increasing numbers of nuclear androgen receptors (increases responsiveness to androgens and decrease in apoptosis)
Asymmetric enlargement, envolving both glandular and prominent stromal elements

Question 13

How is oestrogen throught to play a role in BPH?

Answer 13

• Increases the sensitivity of the prostate to dihydrotestosterone bu inducing nuclear dihydrotestosterone receptors and promoting stromal and collagen synthesis
• May also exert inhibitory role on cell death

Question 14

What are the Tx options for BPH?

Answer 14

• Castration - resolution within a few days

Medical:
- Antiandrogens - delmainone acetate. Progestogen with antiandrogenic and antioestrogenic activity by suppressing interstitial cell function. Flutamide binds to dihydrotestosterone receptors
- LH Inhibitors - Megestrol acetate, medroxyprogesteronei - progesterone derivatives that inhibit LH release and suppress 5alpha-reductase. May induce squamous metaplasia
- GnRH agonists/analogues - block pituitary receptor sites, causing reduction in natural LH-RH and decline in testicular secretion of testosterone. Can be given as long acting injection or implant
- 5alpha-reductase inhibitor - Finasteride
- Oestrogens - Can cause BM aplasia and prostatic metaplasia…

dyschezia is the most common clinical sign

Question 15

prostatitis

Answer 15

• The most common route of infection is considered to be ascending via the urethra
• suggests that benign prostatic hyperplasia is an important prerequisite
• dyschezia and pain on defecation; pain on urination is also commonly seen. A purulent or sanguineous penile discharge (+/- pyrexia)
• Prostatic abscesses have a highly characteristic and virtually pathognomic multiloculated appearance on ultrasound
• FNA sampling

Question 16

List the natural defense mechanism against bacterial prostatitis

Answer 16

• SHedding or uropathogens bound to exfoliating urethral cells
• bacterial trapping by secreted mucous
• Intermittent washout by urine
• Local immunoglobulins, cytokines and defensins
• Mobilisation of leucocytes

Question 17

What is the most common bacterial cause of prostatitis?

Answer 17

E.Coli

Question 18

List the surgical options for prostatic abscessation

Answer 18

• Castration and ABx
• marsupialisation (rarely done)
• Active or passive drainage (20% mortailty)
• Omentalisation (consistently sucessful, low complications)
• Partial prostatectomy (risk of incontinence and severe haemorrhage)

Question 19

What ABx have good penetration of the blood-lipid barrier of the prostate?

Answer 19

• Enrofloxacin
• Marbofloxacin
• TMS
• Chloramphenicol
  Barrier is likely less functional in the inflamed prostate so this is of unclear significance

Question 20

Discrete Prostatic Cysts

Answer 20

• large solitary cysts is less common. Their cause still remains unclear,
• “paraprostatic” cysts, which appear to develop separately from the prostate and do not communicate with the parenchyma but usually have some attachment to the capsule
• “prostatic” cysts, which develop within the capsule of the gland itself
• speculation that paraprostatic cysts represent an anomaly of embryonic remnants of the Müllerian ducts has never been substantiated in dogs.

Question 21

What are the surgical options for prostatic cysts?

Answer 21

Complete resection if small and minimally attached
Partial resection and omentalisation

Question 22

What is the most common form of prostatic neoplasia?

Answer 22

Adenocarcinoma

Androgen receptor negative - castration is not an effective Tx
increased incidence and more frequent development of pulmonary metastasis in castrated dogs
(prepubertal castration may be protective)

ddx SCC, transitional cell carcinoma, and undifferentiated carcinoma

Question 23

What gene has been associated with an increased risk of prostatic carcinoma?

Answer 23

short CAG-1 repeats in the andorgen receptor gene

Question 24

How can prostatic carcinomas be subclassified?

Answer 24

Differentiation
- glandular
- urothelial
- squamoid
- sarcomatoid

Growth patterns:
- papillary
- cribiform
- solid
- small acinar/ductal
- signet ring
- mucinous

Consistent aggressive with high met rate 80% and 20% mets to axial skeleton

Question 25

What % of prostatic carcinoma cells express COX-2?

Answer 25

75%

Question 26

What are the Tx options for a prostatic carcinoma?

Answer 26

* Tube cystotomy or urethral stenting for palliation * NSAIDs - improve survival * complete prostatectomy (significant postoperative complication rate (particularly incontinence) with progression of dz) * Radiation (Stereotactic irradiation to a precisely focused target, Intensity-modulated radiation allows dose to conform more precisely to the three-dimensional shape of the tumor) * Nd:YAG partial prostatectomy

Question 27

prognosis for canine prostatic carcinoma is guarded because of the aggressive nature

Question 28

List anatomical differences of the feline prostate

Answer 28

Only partially encircles the urethra (dorsolaterally) Can have some prostatic tissue disseminated within the urethral wall caudal to the prostate

Question 29

Sx

Answer 29

- involve some potential for intraoperative contamination; patients should therefore receive broad-spectrum perioperative antibiotic therapy - placement of the urethral catheter aids identification of the prostatic urethra - prostatic vascular supply and hypogastric and pelvic nerves are found on the dorsal aspect of the prostate,

Question 30

Prostatic Abscesses/cyst sx

Answer 30

- Stab incisions - oculations within the parenchyma are then broken down by digital exploration - flush and suction - cyst: To avoid risky area dissections, the cyst is partially resected, leaving the attachment of its base to the prostate gland intact. Ventral Drainage - Drains are left in situ until the bulk of the fluid drainage subsides - complications, development of urethrocutaneous fistulas, premature drain loss, and mortality rates of 20% Omentalization - The physiologic drainage properties of the omentum - omentum is packed into the cavity and anchored with mattress sutures through the capsular wall. - eported to be consistently successful for the management of prostatic abscesses; compared with other drainage techniques, - postoperative complication rates are low - Recurrence - Omental metastasis or seeding partial prostatectomy - consdier emporary occlusion of prostatic vascular supply - use of a vessel sealing device - ultrasonic aspirator, which emulsifies and aspirates the tissue - urethra is pressure tested for any signs of leakage - complications: incontinence, hameorrhagem recurrence

Question 31

Total Prostatectomy for Neoplasia

Answer 31

- carcinoma: condition's generally poor prognosis and the procedure's lack of impact on the systemic disease - pubic symphysiotomy to improve access to the pelvic urethra. - onsiderable potential for hemorrhage, and temporary aortic occlusion - urethra is catheterized - Length of urethra to be sacrificed> An end-to-end anastomosis - catheter remains in situ for 5 to 7 days postoperatively - Urinary incontinence is likely after total prostatectomy

Question 32

Investigation of the use of microwave ablation with and without cooling urethral perfusion for thermal ablation of the prostate gland in canine cadavers Traverson 2021

Answer 32

microwave ablation +/- cooling urethral perfusion for ablation of prostate gland in canine cadavers. laparotomy with ultrasound-guided MWA, scope performed before and after treatment urethral mucosal discoloration and loss of integrity were significantly higher (more severe lesions) for the non-cooling group. Some minor denuding of mucosa present in both groups Overall median percentage prostate gland ablation 73%;

Question 33

Prospective comparison of prostatic aspirate culture and cystocentesis urine culture for detection of bacterial infection in dogs with prostatic neoplasia K. A. Skorupski 2022

Answer 33

Prospective. comparison of prostatic FNA vs cystocentesis urine culture for bacterial infection in 10 dogs with prostatic neoplasia. urine culture sensitivity 87.5% and specificity of 50% prostatic aspirate culture not more sensitive for detecting prostatic infection than urine culture A recent retrospective: urine and prostatic culture were discordant in 50% of cases

Question 34

Surgical treatment and outcome of sterile prostatic cysts in dogs Sara Del Magno 2021

Answer 34

Retrospective. outcome of sterile prostatic cysts in 44 dogs Extra- and intraparenchymal: 29 and 11 dogs Extraparenchymal > partial resection and omentalization (n = 22) and complete resection (n = 7). Intraparenchymal > Drainage and intracapsular omentalization in all Resolution (88.6%). Intraoperative complications 1 (urethral tear). postoperative urinary incontinence (10/44) 22% Major complications > 3 dogs death (obstruction, AKI) Recurrence > two dogs

Question 35

Total prostatectomy as a treatment for prostatic carcinoma in 25 dogs Tristram C. Bennett 2018

Answer 35

retrospective Total prostatectomy for prostatic carcinoma in 25 dogs 15 TCC, 8 prostatic carcinoma anastomotic techniques: urethrourethral 14 dogs, cystourethral 9 dogs, ureterocolonic 1 dog, All dogs survived to discharge. Permanent urinary incontinence (35%). 4 major complications (16%) and 16 minor complications. 21 adjunctive therapy, mitoxantrone and NSAIDs recurrence > 30%. Metastatic disease (50%) MST 231 days (189 for TCC) > almost 30% survived >1yr Survival vary widely, depending on the stage and treatment pursued Case selection = small, intracapsular primary lesions, without evidence of metastatic disease Previous study > Total prostatectomy does not result in urinary incontinence in dogs free of prostatic disease, surgical procedure itself cannot account for urinary incontinence

Question 36

Zambelli 2022 – total perineal prostatectomy (concurrent perineal hernia) - advantages: surgical time reduced, improved visualization/mobilisation of prostate no need for pelvic osteotomy, subjectively vesicourethral anastomosis easier - no post-op complications related to prostatectomy, no long-term incontinence | animals

Question 37

Influence of conventional versus unidirectional barbed suture on leakage pressures in canine vesicourethral anastomosis: An ex-vivo study Eric Monnet 2023

Answer 37

conventional vs unidirectional barbed suture for canine vesicourethral anastomosis - no statistically significant difference in acute leakage pressure (8.6mmHg vs 11.7mmHg) - urethral catheter still required to prevent extravasation - shorter sx time and fewer suture bites

Question 38

Comparison of leakage pressures of vesicourethral anastomosis performed with intracorporeal suturing in a simulator and conventional suturing ex vivo in canine cadaveric tissue Ahmed Hafez 2022

Answer 38

leak pressures for vesicourethral anastomosis with intracorporeal suturing, ex vivo - no difference to conventional sutures - potential for laparoscopic radical prostatectomy

Question 39

Stans 2020 – review of prostatectomy for prostatic neoplasia - survival outcome: 32-231d combined with adjunct treatments - total prostatectomy may extend survival as a palliative treatment - complications: urinary incontinence 33-100% - evidence insufficient to suggest survival benefit over less invasive treatments as a sole tx

Question 40

Iizuka 2022 – medical vs surgical treatment of prostatic adenocarcinoma - prostatocystectomy performed with placement of bilateral SUB with distant stent located in the distal urethra - MST: surgery 337d longer than non-surgical 90.5d - longer for total prostatectomy (510d) vs prostatocystectomy (83d) - incontinence: total prostatectomy 50% mild, 30% severe prostatocystectomy 100% severe | BMC