Ch 120 Adrenal glands Flashcards

Question

What diagnostic tests can be used to differentiate a cortisol-secreting tumour from a phaeochromocytoma?

Answer 1

* LDDST ( pituitary-dependent hyperA + adrenal mass and clinical signs of cushings, suppression during the LDDST supports presence of non–cortisol-secreting tumor (e.g., pheo)) * Urine creatinine:normetanephrine ration * Serum inhibin assay (dogs with adrenocorticism will have persistantly elevated inhibin, phaeo will have undectable levels)

Answer 2

normal-sized contralateral adrenal gland and normal adrenal function on screening tests for hyperadrenocorticism.

Answer 3

76% functional Aldosterone most common

Answer 4

77% survive at least 2 weeks MST 50wk

Answer 5

40% - Therefore if suppression occurs, can confirm it is pituitary dependent, however, if no suppression, cannot differentiate

Answer 6

Both PCC and ACT can behave benign or malignant ACT more likely to be adenocarcinoma and cause nodules in the adrenocortical layer. PCC more likely to be benign and may take up the whole gland Invasiveness of ither considered to be a sign of malignancy (kyles 2003) Cavalcanti 2020 revealed that small, non-invasive tumors can be up 50% of the time malignant. Benign adenomas can also be invasive. PCC generally thought to exhibit more invasive biology, more often into th phrenicoabdominal a. invasion seen in 35-50% with mets present in 14-27% at dx. ACC invasive rate of 13%

Answer 7

cortisol-induced immunosuppression, impaired wound healing, systemic hypertension, hypercoagulation > P T E development of hypoadrenocorticism pancreatitis

Answer 8

* Pre-op treatment with trilostane for 2-3 weeks (goal is post-ACTH cortisol of 2-5mcg/dL and reduction of clinical signs) * Frequent short walks within 4 hours after surgery * Keeping anaesthesia as short as possible * Minimally invasiv techniques may help to decrease tissue trauma and have a faster return to ambulation

Answer 9

- pre-tx with trilostane can reverse metabolic derangements of hyperadrenocorticism and potentially minimize many of the complications - routine blood and urine tests, systemic blood pressure - thoracic radiographs are performed to ensure that metastatic disease is not present - risk of intraoperative hemorrhage, blood is submitted for cross-matching

Answer 10

- competitive inhibitor of 3-β-hydroxysteroid dehydrogenase, which mediates adrenal conversion of pregnenolone to 17α-hydroxyprogesterone, another cortisol precursor. - The net effect is inhibition of cortisol production.

Answer 11

PTE Hypoadrenocorticism (glucocorticoid +/- mineralocorticoid)

Answer 12

Hypoxaemia Hypocapnia Increased Aa gradient on room air

Answer 13

- within the first 72 hours after surgery and is associated with a high mortality rate. - no decreased incidence of postoperative thromboembolism with perioperative anticoagulation - walks post op dx - nonspecific and highly variable - dyspnea, tachypnea, and letharg - Depending on the severity V:Q mismatch, somehave poor response to oxygen therapy. - Thoracic radiographs may be normal - Selective pulmonary angiography is the gold standard for diagnosis

Answer 14

* Oxygen * Mechanical ventilaton may be needed * Unfractionated heparin * Judicious IVFT * Theophylline (bronchodilation, pulm vasodilation, increased diaphragmatic contractility) * Sildenafil - In documented pulm hypertension

Answer 15

Glucocorticoids - Acute hypocortisolism occurs in all dogs after surgical removal of a cortisol-secreting adrenal tumor. - dexamethasone (0.05 to 0.1 mg/kg total dose) should be administered in fluids over a 6-hour period. - An ACTH stimulation test can be performed immediately after surgery in order to establish baseline adrenal function. - Physiologic doses of glucocorticoids are administered until ACTH stimulation test results return. - (0.25 to 0.5 mg/kg q12h) post op - 0.1 mg/kg/day by 10 days after surgery. - At 4 weeks after surgery, repeat ACTH Mineralocorticoids - Development of mild hyponatremia and hyperkalemia is common within 72 hours of adrenalectomy - usually resolves in a day or two - treatment if the serum sodium <135 mEq/L or if potassium > 6.5 mEq/L. - injection of desoxycorticosterone pivalate

Answer 16

prednisone and desoxycorticosterone pivalate supplementation must be continued indefinitely

Answer 17

Alpha-adrenergic receptor blocker

Answer 18

Atenolol or propanolol (beta-adrenergic antagonist)

Answer 19

- MRI or CT should be considered to determine the invasiveness of the tumor or presence of associated caval thrombi. - A cross-match blood - Chronic catecholamine exposure in dogs with pheochromocytoma can cause generalized vasoconstriction - removal > acute decline in circulating catecholamine levels can result in decreased vascular tone and a precipitous decrease in vascular resistance - intraoperative tumor manipulation are often associated with surges in blood catecholamine concentrations that can produce acute episodes of intraoperative hypertension, ventricular tachycardia, arrhythmias, and even cardiac arrest (these surges can also occur with adrenocortico tumors) - gradually increase the phenoxybenzamine dosage every few days until clinical signs of hypotension (e.g., lethargy, weakness, syncope), adverse drug reactions (e.g., vomiting), or a maximum dosage of 2.5 mg/kg q12h is attained. - Anesthetic induction is a period of high risk for development of arrhythmias and severe hypertension; - Intra-operative hypertensive crisis > increase inhalant, give acepromazine or nitroprusside (vasodilator)

Answer 20

- permits examination of other abdominal structures for evidence of metastasis and provides better exposure of the vena cava if vascular occlusion is required during resection - more challenging in deep chested dogs - right adrenal gland> aided by transection of the hepatorenal ligament - midline incision can be extended into a paracostal incision to provide improved access - nonabsorbable monofilament sutures in consideration of the delayed healing

Answer 21

- improved exposure to the dorsal abdomen and avoids the risk of abdominal herniation through a ventral midline incision - unilateral, uncomplicated adrenal masses - 10-cm paracostal incision - abdominal muscles are separated using a grid incision -

Answer 22

- resulted in few intraoperative complications - right or left adrenal gland was obtained using a lateral transabdominal approach, with one portal used to place a retractor dorsal to the kidney and the three remaining portals arranged in a semicircular manner - disadvantage > disruption of the tumor capsule is common ( seeding) - modified approach with the patient positioned in sternal recumbency - improved visualization and exposure provided by laparoscopy, the small incisions

Answer 23

- retraction by a surgical assistant is extremely helpful. - smaller tumors without vascular invasion are most amenable to minimally invasive approaches. - phrenicoabdominal vein is isolated, ligated or attenuated - gland is retracted medially, exposing multiple penetrating vessels - bipolar electrocoagulation or a vessel sealing device - caudal aspect > Small adrenal branches that arise from the renal artery - Malignant tumors may invade renal vasculature or parenchyma > unilateral nephrectomy may be required

Answer 24

preoperative imaging findings suggest invasion, preoperative measures include: - blood cross-matching is indicated. - Some surgeons advocate use of intraoperative hypothermia (esophageal temperature of 32°C) - Rumel tourniquets are placed loosely around the vena cava - thrombectomy is performed by making a longitudinal incision in the vena cava - The venotomy is continued with Potts scissors - partial occlusion clamp is placed to isolate the venotomy, and the Rumel tourniquets are released - minimize the risk of air embolism, a small amount of blood may be allowed before clamp. - acute suprarenal caval resection success in a case, suggesting that chronic partial obstruction may lead to development of collateral circulation in some dogs

Answer 25

- 11% to 16% of dogs with adrenocortical tumors - 35% to 55% of dogs with pheochromocytoma more commonly RIGHT (though 20% of dogs with left-sided tumors in one series)

Answer 26

- unacceptable hemodynamic consequences, - 60% decrease in cardiac output, - temporary or permanent renal dysfunction - even death experimental: gradual occlusion of the suprarenal vena cava was achieved in normal dogs without hemodynamic compromise,

Answer 27

historical mortality rates - 13% to 60% in dogs with adrenocortical neoplasms - 9% to 47% in dogs with pheochromocytoma - 4% to 22% most recent case series > improvements in preoperative management and anesthetic techniques - 5.7% > lang 2011 - recent data contradicted tumor invasion into the vena cava is associated with increased operative mortality - Mortality rates are higher in dogs with very large tumors or acute adrenal hemorrhage survival - 3-year survival for pheochromocytomas 60% and adrenocortical carcinomas 90%, - Median survival time was 15.4 months for all dogs medically managed

Answer 28

- 91% had cortical tumors (17 carcinomas, 13 adenomas), and 3 cats had pheochromocytomas. - Function tests: 76% functional, most common finding being hyperaldosteronism - 77% surviving for at least 2 weeks. Median long-term survival was 50 weeks. - poor tolerance of medical management, bilateral adrenalectomy has been performed in cats > mortality high

Answer 29

Retrospective case series of 32 client-owned dogs. 30 (93.8%) died or were euthanized and 2 (6.2%) dogs survived The median survival time was 50 days The most common cause of death or euthanasia was hemoabdomen (n = 8)

Answer 30

Thromboelastography (TEG) is a whole blood assay that yields global assessment of hemostasis, as it evaluates clot time, strength, and kinematics of clot formation and lysis 30 dogs that had preoperative TEG and adrenalectomy performed 53% (16/30) of the dogs were hypercoagulable 4 of 8 HAC dogs were hypercoagulable and 2 of 6 non-HAC dogs were hypercoagulable the majority of dogs with adrenal neoplasia are hypercoagulable In addition, prospective studies are needed to determine whether a hypercoagulable state identified by TEG correlates with clinical development of thromboembolic disease and whether HAC dogs are at greater risk of developing TEG complications.

Answer 31

unilateral adrenalectomy for primary hyperaldosteronism in cats: retrospective 29 cases neck ventroflexion (59%) > Hypokalaemia in all cats, and hyperaldosteronism in 24. vascular invasion 5 cats One major intraoperative complication (3%) > haemorrhage One fatal complication (3%) > DIC 97% of cats survived to discharge MST 1082 days In the majority > clinical signs resolved after surgery

Answer 32

retrospective 65 dogs. short-term outcome for adrenalectomy without pre-op medical management - 49/65 adrenocortical (11/49 bilateral), 13/65 phaeochromocytoma (1 bilateral) 3/65 different tumours in each gland - 5/65 CVC invasion hydrocortisone CRI in 44 dogs. 7 require intraop blood transfusion - mortality: 1/65 (1.5%), major complications 1/65 (1.5%) - minor complications 10/53 (15%) > regardless of tumour type were V+ and D+ (pancreatitis?) - post-op ROTEM and clopidogrel or rivaroxaban (Factor Xa inhibitor) as indicated the added value afforded by pre-operative treatment is questioned. benefits of pre-operative trilostane treatment have not been objectively evaluated evidence to support pre-operative treatment with phenoxybenzamine if previous death results censored.. Herrera > no significant difference with and without pre-op phenoxybenzamine in maximum BP,or the number of hypertensive episodesintraop

Answer 33

6 dogs Median maximal tumor diameter was 2.6 and 2.3 cm Conversion to open laparotomy was performed in 1 dog All dogs survived to hospital discharge

Answer 34

34% emergency surgery – associated with need for intra-op blood transfusion - complications: short-term (<14d) 42% - short-term mortality: 21% - -ve px factors: emergent sx, intra-op hypotension, additional sx procedures - pre-op phenoxybenzamine tx not associated with improved outcome - overall MST: 574d; 900d after censor of short-term mortality - not associated with histopathological dx

Answer 35

255 dogs - primary author consideres 5-6cm upper limit of cases - conversion rate: 9.4% - increased with increased BCS and lesion size - intra-op complications: capsular penetration 19.2%, major hemorrhage 5.4% - survival to discharge: 94.9% - risk of death increased with increasing lesion size - capsular penetration during sx → increased risk of recurrence - surgeon experience → lower sx times, conversion rate and risk of death

Answer 36

The adrenal mass had a caval thrombus extending almost to the level of the right atrium remove the thrombus with a combination of gentle traction and milking from the thoracic caudal vena cava were unsuccessful,.

Answer 37

hypertension: overall 46/53 – 37/46 pre-treated - pre-treated → intra-op systolic BP higher by up to 20% - arrythmia: overall 16/53 – 11/16 pre-treated - survival: operative 100%, to discharge 44/53 (83%); MST 1169d - pre-op α-blocker, post-op anti-coagulant not associated with survival - recurrence: 3/44 (6.8%), metastasis 8/44 (18.1%)

Answer 38

The length (11.6 ± 2.1 mm) and height (6.1 ± 1.3 mm) were the most consistent biometrical parameters to describe adrenal glands.

Answer 39

Ultrasonographic adrenal gland size healthy adult cats maximum normal (3.9 mm ⩽4 kg and 4.8 mm >4–8 kg)

Answer 40

Incidental adrenal gland masses were detected in 25 of the 270 (9.3%) dogs. Dogs with incidental adrenal gland masses were significantly older

Answer 41

5/5 survival to discharge, 4/5 survival at the end of study median 510d

Answer 42

short term survival: 92%; 1y disease-specific survival 83.3% - major complications: 6/51 – sudden death, resp arrest, AKKI, haemorrhage, hypotension aspiration pneumonia

Answer 43

percutaneous ultrasound-guided fine-needle aspiration of adrenal gland lesions in 19 dogs Phaeochromocytoma dx 9/19 dogs 1 dog > ventricular tachycardia following aspiration (a phaeo) appears to be relatively safe for incidentally detected with uncertain clinical significance. clinical importance – i.e . functional or malignant

Answer 44

Retrospective. - survival to discharge: 87% overall - risk factors: increased sx time, pre-tx other than phenoxybenzamine - phenoxybenzamine → no effect on peri-op mortality - pre-treated phaeo (85%) vs non-treated (82%) survival to discharge * post-op complications: 25% * tumour-related survival: 3.96y * decreased overall survival: ureteronephrectomy, post-op pancreatitis, aspiration pneumonia

Ch 120 Adrenal glands Flashcards

(73 cards)