11/9/2008

1

Abdominocentesis, Abdominocentesis, Diagnostic Peritoneal Lavage Diagnostic Peritoneal Lavage

d E l Ld E l Land Exploratory Laparotomy and Exploratory Laparotomy (celiotomy), in Small Animals(celiotomy), in Small Animals

Presented by Dr. Ali BaniadamPresented by Dr. Ali Baniadam

Abdominocentesis• Yields useful information in cases of abdominal injury,

peritonitis or ascitesp• Physical and radiographic examinations should proceed

abdominocentesis• Cytologic, microbiologic and biochemical examination

of aspirated fluid may help to establish the diagnosis• Diagnostic peritoneal lavage (using a dialysis catheter) is

the most reliable and accurate method for early ydetection of the intraabdominal injuries

11/9/2008

2

Indications

• Intraabdominal injuries following blunt trauma d i f h bd i l iand penetration of the abdominal cavity

• Shock without apparent cause• Sever thoracic trauma• Determining the cause of pain• Sign of disease involving peritoneal cavity• Suspicion of postoperative GI dehiscence

• Moderate leukocytosis in peritoneal fluid is normal following uncomplicated abdominal surgery ) up to 1000 cells/µL

• Toxic or degenerative cells occur withToxic or degenerative cells occur with overwhelming peritonitis

• Presence of intracellular bacteria is an indication for surgery

• Abdminocentesis is not indicated when there is a good physical or radiographic evidence of the need for exploratory laparotomy

11/9/2008

3

Estimating intraabdominal blood volume

• Observing the lavage sample• The amount of blood can be estimated using the• The amount of blood can be estimated using the

following equationX=(LV) / (P-L)

X= the amount of blood in the abdominal cavityL= the PCV of the returned lavage fluidV= the volume of lavage fluid infused into the abdominalV= the volume of lavage fluid infused into the abdominal

cavityP= the PCV of the peripheral blood before IV infusion of

fluids

• Surgical intervention is indicated when the PCV f i d l l k i hi 5 20of aspirated lavage samples taken within 5-20

min increases to a PCV of over 5%• If an animal in shock does not respond to

aggressive fluid therapy• Retroperitoneal or diaphragmatic injuries mayRetroperitoneal or diaphragmatic injuries may

give false-negative results

11/9/2008

4

Diagnosis

• Microscopic examination of the aspirate’s sediment: detection of injury to the viscussediment: detection of injury to the viscus

• Cytologic examination: abdominal neoplasia• Chemical analysis: biliary tract injuries (bilirubin

test), pancreatitis (amylase activity), urinary tract injuries (creatinine and Urea concentration),

f i f ll i i (Alk liperforation of small intestine (Alkaline phosphatase), significant liver trauma (Glutamic-pyruvic transaminase)

Catheter placement

• Preparation of the skin 2 cm caudal to the umblicus, local anethesia containing epinephrinelocal anethesia containing epinephrine

• A 3 mm incision is made through the skin • The bladder should be emptied• Left lateral recumbency• Insertion of catheter with the aid of a metal stylet• If organ enlargement or adhesion is suspected: dorsal

recumbency and insertion of catheter with direct visualization

11/9/2008

5

• Warm, balanced solution is infused by gravity flow at 22 ml/kg

• The patient is rolled gently from side to side• A small amount (20ml) of fluid is removed • The skin is closed• Strict hemostasis • The catheter may be left in place

11/9/2008

6

Exploratory laparotomy indications

• Abnormal accumulation within the peritoneal cavity of abdominal viscera

• Nonresponsive pain• Major organ disruption• Nonresponsive dystocia• Abnormal discharge from abdominal tissue• Inspection and palpation of organs

b b• Microbiologic testing, biopsy, or histopathological analysis

• Trauma and neoplasia

Timing

• Surgery should be timed to maximize the potential for diagnostic and therapeutic successpotential for diagnostic and therapeutic success while minimizing patient insult.

• Diagnostic peritoneal lavage is useful in abdominal trauma cases

• There are no absolute rules to guide the surgeon• It should be performed when the patient is not

responding sufficiently to therapy

11/9/2008

7

Technical consideration

• Preparation: Patient preparation should maximize surgical optionsAn incompletely prepared ventral abdomen is no excuse for in complete surgical evaluation

Surgical Approaches

• Ventral midline Th i i i h ld t d f th i h id t– The incision should extend from the xiphoid process to immediately cranial to the pelvis

• Paracostal extension of a midline incision• Paracostal

– incision begins at the xiphoid process, continues parallel and three to four cm caudal to one costal arch and extends to athree to four cm caudal to one costal arch, and extends to a point level with the end of the last rib

11/9/2008

8

Views of the abdomen of the dog showing the common sites for incision

11/9/2008

9

Equipment Needed

• A standard soft tissue surgical pack• Noncrushing intestinal forceps• Electrocautery device• Vascular tourniquet• Intestinal forceps

Surgical technique• Exploratory laparotomy techniques are

essentially the same regardless of the clinical signs of the patientsigns of the patient

• After entry into the peritoneal cavity, microbiologic samples of peritoneal fluid are collected

• Isolation and control of serious hemorrhage and active gastrointestinal leakage should be the first g gstep

• A thorough, systematic exploration of the abdomen, size, shape, location, consistency, surface contour

11/9/2008

10

Ventral view of dog after removal of ventral abdominal wall and the

greater omentum

Ventral view of dog after the removal of the ventral body wall, stomach and intestines

11/9/2008

11

Exploration of the peritoneal cavity

• The cranial extent of the abdomen is evaluated first: • Diaphragm (transection of triangular ligament betweenDiaphragm (transection of triangular ligament between

the liver and diaphragm, although often unnecessary), • Liver lobes, gall bladder, hepatic hilus• Inspection and palpation of the stomach• Spleen and greater omentum (exteriorization)• After replacement of the spleen, mesentric arterial

p l ti d p ri t lti ti it h ld l bpalsation and peristaltic activity should also be evaluated

• The duodenum and pancreas• The use of mesoduodenum as an anatomic

retractor gently improves visulaization of the right paraverteral regionPortal vein, caudal vena cave, celiac artery, hepatic lymph nodes, right kidney and proximal ureter, right ovary and uterine horn

• Duodenum is traced to the dudenocolic ligamentg

• Jejunum, cecum, descending colon

11/9/2008

12

• The mesocolon as a rtractor enable the surgeon to examine the left paravertebral area

• Left kidney and proximal ureter, aorta, left adrenal gland left ovary and uterine hornadrenal gland, left ovary and uterine horn

• Distal colon, urinary bladder, distal urter, proximal urethra, prostate gland, ductus deferens or uterine body and vagina

Biopsy techniques

• During exploratory laparotomy, gross evaluation d i i l f d idand interpretation alone often do not provide a

definitive diagnosis• Frequently: Liver, intestines, lymph nodes,

kidneys, prostate gland• Less commonly: stomach spleen urinaryLess commonly: stomach, spleen, urinary

bladder, grater omentum

11/9/2008

13

Liver

• Finger of instrument fragmentation technique• Wedge resection technique: two rows of full-

thickness horizontal mattress suture• Use of cutaneous punch: hemostasis is achieved

by inserting a topical hemostatic agent or omentumomentum

11/9/2008

14

11/9/2008

15

Small intestine

• Obtain full-thickness intestinal wall sampleI i i h• Incision transverse to the mesentery

• The biopsy incision should not exceed 20% of the intestinal circumference

• The incision is closed in a single layer using appositional suture pattern with synthetic absorbable or monofilament nonabsorbable suture material

• Protection by greater omentum

Lymph nodes

• Fine-needle aspiration technique: cytological l ievaluation

• Excisional biopsies: morphologic interpretation

11/9/2008

16

Kidneys and prostate gland

• Needle biopsy techniqueTh dl i i d h h h l lThe needle is inserted through the renal capsule at the caudal aspect of the kidney and is directed within the cortex toward the cranial pole.Digital pressure to achieve hemostasis

• Wedge resection biopsies: After excision a wedge-shaped segment the defect is closed with mattress suture

11/9/2008

17

Other tissues

• An elliptical section of gastric wall from one side f h d dof the gastrotomy wound edge

• Partial splenectomy• Partial pancreatectomy• Urinary bladder biopsies after cystotomy• Excising a section of omentum

11/9/2008

18

Therapeutic intervention

• Hemorrhage control• Correction of the source or sources of

contamination and pain• Removal of mass lesions or intestinal

obstructions• Eli i ti f b liti• Elimination of abnormalities

Intraoperative peritoneal lavage

• Peritoneal lavage using one to three liters of warm isotonic solution is beneficial because itwarm, isotonic solution is beneficial because it facilitates aspiration of such contaminations as soft tissue fragment, bacteria, blood clots and fat.

• Lavage also warms the patient• It is important to suction the lavage fluid p g

completely before closure of the wound• Antibiotics, antiseptics and anticoagulants

(heparin: 100 µg/kg) can be added to peritoneal lavage

11/9/2008

19

Wound closure

• Sutures are placed approximately 3 to 10 mm from the wound edgewound edge

• The sutures should only incorporate the linea alba and external sheath of the rectus abdominis muscle

• Closure of a paramedian approach( 5 mm lateral to the linea alba) is accomplished by suturing the external sheath only

• Closure of the internal sheath of the rectus abdominisis unnecessary

• The peritoneum heals quicker and with fewer complictions if it has not been sutured

• The simple continuous pattern using p p gnonabsorbable synthetic sutures has been demonestrated to be efficient and effective clinically

11/9/2008

20

11/9/2008

21