Bovine GI Surgery & Dx Flashcards

Question

Sites for laparoscopic entry to the bovine left flank

Answer 1

1. Cranial site = 3-4cm caudal to last rib, 8cm ventral to TPs 2. Caudal site = 5cm cranioventral to the distal end of the TC. This site is also used in the RIGHT flank

Answer 2

Usually dt (but not exclusive) rumen distension assoc w VI \> Failure of eructation \> Omasal transport failrue (TRP) \>Pyloric outflow obstruction \> Late gestation

Answer 3

Usually indicates free abdominal fluid eg uroperitoneum or diffuse peritonitis More symmetrical distension than with the others Abdominocentesis for characterisation of fluid and hopefully dx

Answer 4

Free gas bloat Peri-ruminal abscesses (eg post rumenotomy) - US/centesis for dx

Answer 5

2-3 contractions every 2 mins Assessed with a fist in the left PLF to palpate contraction Rumen has 1ary & 2ary contraction cycles 1ary - assoc w mixing ingesta 2ary - assoc w eructation. Rumination is a specialised form of secondary contraction stimulated by coarse material in the reticulum and rumen.

Answer 6

Holotrics & Entodiniomorphs Holotrics have cilia all around the cell Entodiniomorphs have cilia at 1 ENd only Although bacteria are more important for digestive function, the ruminal protozoa are easier to assess diagnostically, and they provide a reasonable index of ruminal health the adult the rumen contains between 10⁵ - 10¹² bacteria/mL

Answer 7

Normal colour is grey-green - green - brownish-yellow, depending on the diet. Milky grey or yellow fluid is associated with carbohydrate engorgement. pH oranges from 5.5 - 7.0 in healthy cattle on a balanced ration. Cattle on high-carbohydrate diets have lower pH values than those on roughage diets. Acid pH \<5.5 in an anorectic ruminant indicates ruminal acidosis. pH \>7 indicates ruminal alkalosis - often dt simple rumen inactivity, or anorexia

Answer 8

Add 1 part 0.03%nMB dye to 20 parts strained rumen fluid Normal rx is dye cleared in 5-6min

Answer 9

Similar as for horse ## Footnote MMC initiated in the duodenum & consists of 3 phases - Phase I is characterised by \<10% of the slow waves being superimposed by spikes. Phase II is usually the longest; = irregular spiking activity, with between 10%-99% of slow waves superimposed by spikes. Intense mixing of gut contents takes place during phase II. The last few minutes of phase II are thought to be responsible for propulsion of intestinal contents. Phase III is the phase of regular spiking activity, with 100% of the slow waves being superimposed by spikes. The role attributed to phase III is to clean the lumen of debris and residual content and to prevent retrograde flow of intestinal contents (house- keeping function)

Answer 10

A - ileum B - Caecum C - proximal loop of ascending colon (PLAC) D - spiral colon (centripetal loops going in, fugal loops coming out) E - distal loop of ascending colon F - transverse colon G - descending colon H - rectum

Answer 11

Hypochoraemic metabolic alkalosis (NB w RVA & ischaemia can see acidosis & normalisation of pH - red flag for RVA) Hypokalaemia usually present concurrently - preserve K+, excrete H+ instead

Answer 12

Both done via left flank 1) Rumen board (Weingarth apparatus) hooks for securing rumen at intervals along length. Care not to contaminate inner surface of the board 2) Suturing - suture seromuscular layers of rumen to the skin before rumenotomy

Answer 13

Medical - apply magnet; may return FB to reticular lumen in 50% cases. Confinement, ABx, fluid therapy etc Surgical - left flank approach. Expliore cranial abdo for adhesions/abscesses Rumenotomy (Weingarth or suturing). Evacuate rumen contents then palpate reticulum. Remove all FB & search hard if suspicious. Locate abscess & drain into reticulum w guarded blade (unless its not tightly adherent to rumen wall - so have to drain percutaneously). POOR PX if FB penetrated diaphragm GUARDED px if penetration involves right reticular wall (VI) FAVOURABLE px if no involvement of thoracic cavity or right reticular wall

Answer 14

Streptococcus bovis pH \<5.5

Answer 15

Altered abomasal motility - ulcers etc Anatomy - early lactation - void uterus Metabolism - -ve EB; 57% within first 2 weeks lactation, 80% first month, 91% 6 weeks Other peri-parturient disporders also predispose - metritis, mastitis, Diet - high concentrates, low fibre -ve EB = fat mobilisation - NEFA \>0.5mEq/L 3.5X more likely to get LDA BhB \>200umol/L 3.8X risk & 8x risk \>1200umol/L

Answer 16

Cast into R lateral (as for NSE; gas filled viscus has to be located dorsally - left side in both conditions) Roll into dorsal & listen to ping; maintain dorsal until ping goes (can decompress w 14g needle) Roll into left lateral, confirm no ping. High success rate upto 90% resolve the ping but high recurrence upto 70% witihn 6 weesks. Cheap but cost of production losses make up for this

Answer 17

1. Cast into R lateral 2. Roll into dorsal. Perform fixation at the centre of the ping - should be right cravioventral abdomen (should be between midline & mild vein, several cm caudal to xyphoid) 3. Blind tack - upholstery needle w 30cm suture threads; placed through skin, abomasum & back through skin & tie. Repeat second suture if ping remains large enough 4. Toggle pin - 12Fr trochar/cannula enters abomasum (gas rush) - & 10Fr toggle inserted via canula w trochar then remove. Can repeat 5-10cm caudal/cranial if ping remains 5. Don't tie sutures tight - willnecrose through wall; need 1-2 fingers space or tie over gauze 6. Release at 2d if no better. Otherwise cut in ALL casses at 2-3wk or will get fistula 7. Px 77-93% blind tack, 80-88% toggle pin 8. BUT complications can be severe incl. incorrect position (outflow obstruction), fistula, peritonitis, wrong organ etc

Answer 18

1. SITE: needs to be close to pyloroduodenal junct. without compromising duodenal function - choose 6-8cm vertical portion of omentum no more than 3-4cm caudal to pyloroduodenal junct. (avoid using 'sow's ear as 1° target dt inconsistent location) 2. Pexy as wide an area of omentum to ↑ strength, ↓tension 3. Ibcorporate peritoneum into pexy 4. Use long lasting/non-absorbable suture to allow time for fibrous adhesions 5. To be in functional position, pexy needs to be in the cranioventral incision to allow pylorus to lieICS9-10. Extend ventrally if under tension. Keep PLF incision close to last rib if anticipating pexy. 6. Pexy - 1.5cm fold of omentum incorporated w 3x horizontal mattress sutures 2cm apart through all 3 mm layers & **peritoneum** (↑strength) w non-absorbable suture 7. Incorporate omentum into 1st layer of incision closure w transversus & peritoneum - closes gaps

Answer 19

98.5% short term cure Failure more likely dt concurrent dz (mastitis, metritis etc) Complications incl recurrence - 2-5% dt tearing, stretching, pullout; most comonly dt placing the pexy too far caudal/dorsal in the omentum relative to pylorus - or similarly, flank incision too far caudal/dorsal. RECURRENCE SHOULD BE APPROACHED VIA RIGHT PARAMEDIAN ABOMASOPEXY

Answer 20

1. SITE: at least 5cm oral to pylorus to prevent stenosis 2. Incorporate seromuscular layer into incisional closure w transversus & peritoneum 3. Or can do pyloropexy w 1-2 sutures through all mm layers & peritoneum cranioventral to incision, including thick torus pyloricus mm tied SQ. 4. And then incorporate omentum into incisional closure as for right flank omentopexy

Answer 21

1. SITE: 10-12cm section of serosa 2-4cm to the right of insertion of greater omentum (this appears as vascular serosal covering), caudally from 5-8cm caudal to the reticuloabomasal ligament, w USP1-3 non-absorbable suture 2. Simple continuous patter. MUST incorporate peritoneum in pexy for security & adhesion formation. Pexy incl seromuscular abomasum, peritoneum & internal rectus sheath. 3. Remaining incision in 3-5 layers; NB external rectus sheath is strength holding layer for paramedian incision

Answer 22

Omentopexy only had higher rate of recurrnce vs pyloro-omentopexy No other significant differences between groups were identified (time remaining in herd, cull rates, reproductive failure etc)

Answer 23

High starch diets, hypocalcaemia

Answer 24

Typhlotomy - for non-responsive dilations (ie normal position). Verify normal position, exteriorise caecum, typhlotomy at apex. 2 layer closure - monofilament absorbable, simple continuous then inverting, Caecal amputation - for recurrence post typhlotomy, or devitalisation. Right flank approach standing, block in ileocaecocolic ligament to block caecal nerve. Ligate br of caecal aa/vv close to attachment of ICC ligament. Transect ICC ligament, transect between 2 clamps & close with double inverting layer.

Answer 25

Dilation - distension in normal position Torsion - twisting of caecum itself along its longitudinal axis Dislocation/volvulus - dorsal or ventral retroflexion of the apex when viewed from the right Dislocation - can be used for any twist, torsion or volvulus

Answer 26

Type 1: Mucosa & submucosa only Type II: all layers Type 3: all layers plus variable amount of small colon intussuscepted into the colon Type 4: as for 3 but small colon also prolapsed out of rectum Types 1 and 2 are most common in cattle

Answer 27

1. Submucosal resection: - insert flexible rubber tubing and secure w 2 18g needles at right angles through prolapse and tubing Make circumferential mucosal incisions in front and behind affected area; join the 2 with a longitudinal incision & dissect the mucosa free & discard. Close remaining mucosal edges at 4 equidistant points then fill in the gaps; 2/0 monofilament absorbable 2. Stairstep amputation - tubing & secure as above. Circumferential incision through all layers except inner mucosa. Create plane of dissection caudally between inner mucosa & outer layers. Transect leaving slightly longer mucosal section that can be reflected back & closed to healthy mucosa Both replaced & purse string for 1 week

Answer 28

Duodenoduodenostomy - created between cranial dupdenum & laterally facing visceral surface of the descending duodenum, 20cm aboral to pylorus. in side-side fashion. 13/14 short term susvival 7/8 survived productively within 1 year

Answer 29

Intussusceptions Volvulus Entrapment within umbilical remnants

Answer 30

1. Medical - first line. Magnet & ABs, Most should improve 3-5d 2. Sx - if no improvement. Explore via rumenotomy (left flank) retrieve FB, drain abscesses into reticulum where poss otherwise percutaneously if adherent to abdo/thoracic wall. Drain pericardium where required.

Answer 31

* Exclusively in calves. Often following d+ * see depression, anorexia, tachcardia, dehydration, right sided ping * Tx - right flank PLF in left lateral; manually reduce if poss. May need to resect caecum, ileum, proximal loop asending colin depending on locaiton * High recurrence rates usually necessitate caecal amputation even if bowel is viable * Px guarded

Answer 32

External rectus sheath

Answer 33

1. Rumenotomy 2. Caesarean section 3. Left sided abomasopexy

Answer 34

1. Right-sided pyloro-omentopexy or abomasopexy (this is paramedian typically) 2. Small intestine 3. Caecum, 4. Colon. R PLF approach provides best access to the abdomen & most complete ex-lap in the adult

Answer 35

1. Ventral midline caesarean (oversized, emphysematous foetus or complicated delivery) - incision is from umbilicus caudally. 2. Right paramedial abomasopexy. Paramedian is between midline & SQ abdominal vein from umbilicus cranially toward the xyphoid. 3. (Ventrolateral oblique - used less commonly. Left or right - lateral to SQ ab vein. Also for caesarean. Hard to close)

Answer 36

vertical incision is made in the middle of the paralumbar fossa extending from 3 to 5 cm ventral to the transverse processes of the lumbar vertebrae for a distance of 20 to 25 cm. For rumenotomy in a large cow, it may be advantageous to make the incision cranial to the midway point. For cesarean section, the incision may begin 10cm ventral to the transverse processes and may extend 30–40 cm

Answer 37

3 layers 1. Peritoneum & transversus - simple cont absorbable 0 or 1 2. Int & external oblique - simple cont 1 absorbable 3. Skin - polycaprolactam Ford interlocking w 3-3 SI ventrall incase of req for drainage

Answer 38

FB removal (TRP) Evacuation of contents (grain overload, toxic plants etc) Rumen impaction/atony Atony/impaction of omasum/abomasum

Answer 39

1. Suturing to skin first (most effective seal & least PO complications) 2. Weingart rumen board fixation device 3. Towel clamps to fix the rumen to body wall before incision

Answer 40

* Continuous inverting suture pattern (similar to a Cushing pattern) is used, to pull the rumen over the edge of the skin incision w heavy-gauge material (nylon or polypropolene) * 2 large, inverting sutures placed at the ventral aspect of incision so that the rumen projects well over the skin edge to avoid contamination in the ventral region * Slower vs rumen boards etc but less chance of spillage * Rumen is incised with a scalpel taking care to leave enough room dorsally and ventrally for closure at the end of the procedure * Explore reticulum/remove FBs +/- lance abscesses w blade on a string if present * Closed w a simple continuous pattern using of no. 1 or no. 2 synthetic absorbable. Single layer may be adequate, but a double usually used; 2nd inverting * Thoroughly lavaged after closure prior to removal of the rumen-fixation suture & second layer closure. No further exploration should be done after closure of the rumen

Answer 41

+ abomasum is brought into position more easily in most cases + instantaneous repositioning + abomasum is easily viewed for detailed exam and detection of ulcers; + strong, long-lasting adhesions can be anticipated. - not performed standing - abomasal fistula if retaining suture penetrates the lumen of the abomasum.

Answer 42

* 20-cm right PLF incision from 4–5cm ventral to TPs * When the peritoneal cavity is entered in the case of an LDA, the duodenum will be **vertical** instead of in its normal horizontal position. * Palpate left side of abdomen by deflecting greater omentum craniad. Palpate abomasum distended W gas on left side of the rumen. (+/- adhesions). * Abomasum deflated w 14–16-g needle & sterile tubing. * Abomasum returned to normal position by following peritoneal surfaces ventrally with the hand between the rumen and the body wall. Once to the left of the rumen, the hand, with the fingers closed, is used to sweep the abomasum back to the right side of the abdomen. * Gentle dorsocaudal pulling on the omentum, which has also been displaced to the left, is also helpful in this manipulation. * Once returned to normal position, duodenum resumes its normal horizontal position and is commonly observed to fill with gas. The greater omentum, which is observed through the abdominal incision, also feels loose. * The omentum is grasped and pulled out through the incision. It is gently retracted dorsad & caudad until the pylorus can be visualised. This fold of omentum may be held by an assistant or attached to the upper part of the skin incision with towel forceps while the anchoring sutures are placed. * 2 mattress sutures of no. 1 or no. 2 synthetic absorbable suture material (one cranial to the incision and one caudal to it) are placed through the peritoneum and transverse abdominal muscle and through both layers of the fold of omentum * The sutures are placed about 3 cm caudal to the pylorus. The peritoneum and transverse abdominal muscle are then sutured in a simple continuous pattern with no. 1 or no. 2 synthetic absorbable suture, and the omentum is incorporated into the suture line in the ventral two-thirds of the incision. The internal and external abdominal oblique muscle layers and the skin are closed as in a routine flank laparotomy.

Answer 43

* Flank incision is shifted cranioventral to the middle of the paralumbar fossa. * Skin is undermined for approx 5 cm dorsocaudal & dorsocranial from the dorsal most aspect of the skin incision, for placement of no. 2 absorbable suture through muscular body wall into abdo, where a bite is taken into the omentum and back through the body wall to be tied SQ. These sutures serve to hold the omentum in place dorsally while pyloric antrum is secured to body wall. * The pyloropexy is done w # 1 **nonabsorbable** suture. The cranial body wall is reflected cranially so that interrupted sutures can be placed near the ventral aspect of the incision approx 5 cm cranially. Suture is placed from caudal to cranial through the peritoneum, transverse abdominus muscle, & part of IAO. The seromuscular layer of the pyloric antrum can then be pinched to separate it from mucosa; next bite of suture from cranial to caudal in its seromuscular layer. * 3 such sutures are pre-placed before any are tied. These sutures will place the pyloric antrum immediately adjacent to the body wall. * The omentum is then included in the closure of the peritoneum & transversus from dorsal to ventral in a continuous pattern to the level of the pyloropexy sutures. * 1 review found significant ↓ in recurrence of DA after pyloro-omentopexy vs omentopexy. * Care re luminal penetration (obv not a risk w omentopexy alone)

Answer 44

* Std 20-25cm left PLF lap; care re abomasal penetration when entering the abdomen * Abomasum usually first thing seen at incision, rumen behind it. * 8-12cm simple continuous or interlocking suture line of heavy polycaprolactam, nylon, or polypropylene, is placed in the greater curvature of the abomasum 5–7 cm from the attachment of the greater omentum (serosa may be rubbed with a dry sponge to enhance adhesion formation). Don't penetrate lumen * 1 meter of suture should extend from each end of the suture line, w haemostats on each end for easy identification. Abomasum then deflated w 12g needle & rubber tubing * Cranial end of suture is attached to a large, straight, cutting needle or to an S-curved cutting needle; this needle is carried along the body wall to a position **right of midline, but medial to subcutaneous abdominal vein & 15 cm caudal to xiphoid process.** * The needle is inserted quickly through the ventral body wall w assistant applying upward pressure on abdominal wall in area of penetration. Assistant grasps the needle, & the caudal suture is placed through the body wall 8–12 cm caudal to the cranial suture. * Assistant grasps the 2 suture ends & applies gentle traction; w surgeon pushing abomasum into normal position, where assistant ties suture ends together * Suture tension - should fit 1 fifinger snuggly between abomasum & body wall when tied. * Too loose may allow intestine to become entrapped in the suture loop while too tight may lead to tearing of the suture out of the abomasum. * Suture left in for 4 weeks; ends are then cut as close to skin as possible.

Answer 45

Right of midline but medial to the right SQ abdominal (milk) vein. Approx 15cm caudal to xyphoid

Answer 46

* Not as common as other techniques. An RDA is probably adequately & more easily tx w pyloro-omentopexy. Poss for RVA as disturbance of venous return may → heavy / odeamatous not adequately secured w omentopexy / pyloro-omentopexy * 20-25cm PLF incision. In a simple RDA, greater omentum comes into view through lap in right flank as in a normal animal. Greater omentum may be looser as distance between abomasum & descending duodenum is less than normal. The fundus will typically have moved caudolaterad and will appear uncovered by omentum. * In RVA - usually counterclockwise from rear & counterclockwise when viewed from the right flank. Omentum usually wrapped in torsion site, & abomasum ∴ appears at incision without omentum covering it. * Decompress w 12g needle & rubber tubing; easier to remove gas / fluid before detorsion when abomasum is closer to incision. * Interlocking suture is placed in the middle of the greater curvature near the attachment of the greater omentum same as for left-flank abomasopexy * Sutures exit body wall as for left flank abomasomxy & tied similarly by assistant

Answer 47

* 20cm incision made between midline & right SQ abdominal vein, starting approx 8cm caudal to xiphoid process ending immediately cranial to umbilicus * Incision continued through external rectus sheath (aponeuroses of EAO/IAO) & rectus abdominis, to reveal internal rectus sheath (transversus aponeurosis); incised w peritoneum * In most LDAs, abomasum will return to relatively normal position during casting. * Once in correct position, lateral aspect of greater curvature (where it is **free of omentum**) is incorporated with peritoneum & internal rectus sheath in a simple continuous suture pattern with no. 1 or no. 2 synthetic absorbable suture material - DON'T penetrate mucosa. * External rectus sheath closed w a simple continuous of no. 1 / 2 synthetic absorbable &the skin w Ford interlocking polymerized caprolactam

Answer 48

1. Recurrence - more common w omentopexy vs pyloro-omentopexy 2. Abomasal fistulas - esp in nonabsorbable suture is used or mucosa is penetrated. 3. Inadvertent damage to other viscera - esp w left flank abomasopexy w blind penetration of right cranioventral body wall

Answer 49

1. Right flank omentopexy - 87-100% for LDA. 74% RDA. 3% complications (peritonitis) 2. RVA worse than RDA (obv) 3. Right paramedian abomasopexy - LDA - 81-87%. Less for RDA

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Bovine GI Surgery & Dx Flashcards

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