Principles of GI tract surgery 1, 2 & 3

Recall Halsted's principles of surgery and how you can apply them in GI tract surgery

• Gentle tissue handling

• Meticulous haemostasis

• Preservation of blood supply

• Strict asepsis

• Minimal tension

• Accurate tissue apposition

• Obliteration of dead space

How can we apply gentle tissue handling in the GI tract?

• Sufficient incision size

• Use hands but avoid excessive handling

• Keep tissues moist

• Stay sutures

• Use scalpel for initial incision (extend with scalpel/ metzenbaum)

• Liver and pancreas esp fragile

What manouvre is being shown here?

• Duodenal dam manouvres

  • Exposes right abdomen (right kidney, adrenal gland, ovarian pedicle)

• Can do the same on the other side with colon

What is this instrument?

Balfour retractors

• Gossettt the same without central blade

What is this?

• Poole suction tip (one of the best for GI surgery)

What forceps are these?

Debakey forceps

• Good for gentle tissue handling in GI tract

How can you occlude a gut lumen if you have no assistant?

Doyen bowel forceps or Allis tissue forceps padded with swabs

Where should you incise in the intestine to ensure meticulous haemostasis?

Least vascular part

What part of the stomach should you incise for meticulous heamostasis?

• Halfway between greater and lesser curvatures of stomach

  • If removing part of stomach, ligate major vessels supplying that area

What is the least vascular part of the small intestine?

• Antimesenteric border

  • Except ileum so go 2/3 of the way from mesenteric to antimesenteric border of ileum

If you are going to incise intestine what should you ensure you do?

• Ligate vessels

What is the pringle manoeuvre?

• Temporary occlusion of hepatic blood flow (up to 15 mins)

  • Put pressure through epiploic forman on hepatic artery and portal vein

What is the guillotine method? What method should you use if you're working further down the liver lobe?

Method used to remove a part of liver lobe (for biopsy; can use for pancreas as well)

Finger fracture technique

Why do you need to take care with electrocautery in the pancreas?

• Excessive use can cause pancreatitis

Which of these would be the correct place to incise to remove gut?

Incising at approx 30° to the transverse ensures adequate blood supply to the antimesenteric border and increases the luminal diameter at the anastomosis

• A= bad, as the antimesenteric edge of the incision is further away from the remaining vascular supply than the mesenteric border

• B= better as they are equidistant but

• C= best (with the incision at approximately 30° to the transverse)

How do you assess intestinal viability?

• Colour

• Presence of of arterial pulses

• Ongoing peristalsis

Viable:

Non viable:

What are the features of oesopahgeal blood supply? How do you preserve this?

Segmental blood supply

Rich submucosal plexus

• Preserve by:

  • Avoid excessive cautery

  • Gentle tissue handling

  • Careful suture placement

Label the blood supply? What is the sigfnifance of this?

Careful placement is needed as to not to ligate a vessel that branches into several others so you don't compromise blood flow

Which organs make strict asepsis particualrly important in the intestine?

• Contaminated gut lumen

  • Milk contents away from incision site, then occlude

• Population of clostridia in liver

What can you do to ensure strict asepsis in the GI tract?

• Stay sutures

• Discard contaminated instruments and change gloves before closure

• Lavage abdo before closure (1-3L warm saline) (NO antibac or disinfectant)

What are the features needed for prophlactic AB for them to work?

• Present in tissue when contamination occurs

  • IV before site

• Active against contaminants found in surgical site (Staphs and E. coli most common)

• Continue for up to 24 hours post op

What are some good choices for prophylactic AB for GI surgery? What should you give if working on liver or biliary tract?

• Clavulanate-amoxicillin for general prophylaxis

• Metronidazole for anaerobes

• Amoxicillin and cefazolin actively excreted in bile so would be good choices for that

What are the two major exceptions for tension not being a problem in intestinal surgery?

• Oesophagus (anastomoses difficult bc relatively immobile)

• Colon during subtotal colectomy (prox colon sometimes not mobile enough to allow colocolic anatomoses so would convert to subtotal colectomy with ileocolic anastomoses)

What are the two main methods of making intestinal incision to allow accurate apposition?

• Longitudinal incision, longitudinal closure

• Longitudinal incision, transverse closure (in line with long axis)

NB: avoid transverse incisions

What is the procedure of choice for accurate tissue apposition in an oesophagectomy and enteroctemy?

• End to end appositional anastomosis

Why does the oesophagus heal more poorly?

• Incomplete serosal covering

• Poor vascularity

• Tension and motion

What are the features of the suture material you would use in the GI tract?

• 1.5 to 2 metric

  • Up to 3 metric in stomach

• Monofilament absorbable

  • PDS

  • Polyglyconate (Maxon)

• Avoid multifilament

  • Wicking

  • Act as nidus for bacterial growth

NB: NEVER use cat gut

What layer is very important to be incorporated in the suture?

• Submucosa

  • Strongest layer

  • Accurate alignment needed for adequate healing

What suture pattern do you use in the GI tract?

• Simple interrupted or continous

  • Preserve blood supply

  • Maintain luminal diameter

  • Minimal adhesions

Why may a continuous pattern be better than interrupted?

• Less mucosal eversion

• Less adhesions

• Better submucosal apposition

List some practical steps can you take to minimise the risk of postoperative infection if you’re removing a foreign body from the jejunum

• Exteriorise and pack incision site

• Incise distal to foreign body as gut wall will be empty so less likely to contaminate

• Secure closure with monofilament

• Check for leakage after closure

• Lavage abdo before closure

• Give prophylactic AB

• Change instrument before abdo closure

What suture pattern do you use for the oesophagus?

• Single or 2 layers closure

  • Deep layer: mucosa and submucosa with knots in the lumen

  • Superficial layer in the muscularis with knots on the serosal surface

What suture pattern do you use for the stomach?

• 2 layer closure

  • Simple continuous

  • Continuous inverting Cushing or Lembert

• Alternatively, 2 layers of Cushing or Lembert

What is this showing?

• Suture half circumference intestine at the time in order to avoid creating an accidental purse string suture

NB bites should be 3-4mm from the cut edge of the intestine and 3mm apart

What suture pattern in reccommended in colon?

Simple interrupted

How do you cope with luminal disparity in intestinal closure?

Minor disparity: spacing sutures further apart on the larger side.

Moderate disparity: transect the smaller segment of bowel at a greater angle

Major disparity: incise small incision along the antimesenteric border to increase the diameter of the lumen

If the luminal diamaters are grossly unequal and cannot use above techiques what should you do?

End to side anastomosis

• Oversew end of distal segment

• Suture end of proximal segment to antimesenteric border of distal segment

NB- rare to have to do this

How do you ensure obliteration of dead space in the abdomen?

(Not big problem in abdo)

• Suction lavage fluid

• Always suture mesentery if have made hole in it

How can you utilise the omentum for healing?

Wrap omentum around piece of intestine you have incised

• Rich vascular and lymphatic supply

What technique is being shown here?

Serosal patch

• If have to leave a section inside but worried about viability can use patch of viable serosa

What should you ensure with fluid therapy for a GI tract surgery case

Ensure fluid deficits and electrolyte balances corrected before surgery

Appropriate fluids given intra op

What are the different classifications of peritonitis?

• Local or generalised

• Primary (rare) or Secondary

  • Secondary can be chemical (due to irritants) or septic

What are the consequences of peritonitis?

• Hypovolaemia

• Metabolic acidosis due to reduced tissue perfusion

• Electrolyte imbalances

• Endotoxic shock

• Death

What are the clinical signs of peritonitis?

• Depression

• Anorexia

• Vomiting

• Abd pain and distension (praying position)

• Ileus

• Pyrexia

• Shock

How can you diagnose peritonitis?

• Radiography - contrast reduced

• Haematology - neutrophilia and left shift

• Serum biochem- azotaemia, hypoglycaemia

• Abdo paracentesis- degenerate neutrophils, free and/or intracellular bacteria

  • Compare lactate and glucose to serum

How is peritonitis treated?

• Fluid therapy

• Broad-spectrum antibacterials

• Correct primary cause

  • Exploratory coeliotomy

• Copious peritoneal lavage

• Drainage (rare and referral)

What is an adhesion? What types of adhesions can you get? How do you prevent them?

• Deposition of fibrin (Rare in SA)

• Restrictive or non restrictive

• Prevent by good technique

When may short bowel syndrome occur?

RARE

• After removal of >80% of small intestine (not enough intestine left to

  • Medical management

  • Prognosis poor

What is ileus?

• Inadequate peristalsis of whole GIT leading to functional obstruction

• Due to vagosympathetic reflex

• Whole gut becomes distended and gas or fluid filled

How is ileus treated?

• Correct underlying disease

• Supportive therapy

  • Fluid, metoclopramide

List 2-3 specific things you can do during your daily clinical examination to monitor your patients for postoperative peritonitis

• Check for abdo pain by palpation (remember cats often don't show this)

• Ballotte the abdo for fluid thrill on opposite side

• Weigh them, measure abdo circumference

How do you approach the oesophagus surgically?

For oesophagus to level of 2nd rib: ventral cervical midline

For further down: right intercostal thoracotomy at level of lesion

What location do you perform a coeliotomy for an abdominal approach?

• 5-10cm cranial to the xiphoid to 5-10cm caudal to the pubis

• 10-15cm on each side of the ventral midline

Depends on where the problem is

• For male dog parapreputial incision

How should you perform an incision for coeliotomy?

• Skin and subcut then stab incision through linea alba (horizontal position and blade away from patient)

• Mayo scissors to cut further along

What sometimes restricts exposure of the cranial abdomen in a coelitomy?

Falciform ligament

If necessary, remove it by avulsing it from the abdominal wall, cutting it away with scissors or using electrocautery to cut it away from the wall then ligate

How is a ventral midline coeliotomy closed?

• Close linea alba

  • Single layer of simple continuous in external sheath of rectus abdominis (must incorporate this)

• 5-10mm from edge and 3-12mm apart

What should you ensure when making an incision for a laparotomy (flank incision)?

• Incise muscle layers parallel to fibres

What approaches can you use for the terminal colon, rectum, anus?

• Ventral approach

  • Pelvic osteotomy/ pubic symphysiotomy)

• Anal approach (evert with stay sutures)

• Rectal pull through

• Dorsal 'inverted U' approach

• Lateral approach

If you had a patient with a benign distal colonic / proximal rectal mass just inside the cranial end of the pelvis, what surgical approach would you use to access the affected intestine? Why?

• Ventral midline coeliotomy

  • Benign mass so only requires local excision (not large margins)

  • Allows full-thickness resection

  • Can usually retract that section of the intestine cranially and access via the abdomen

  • Avoids need to cut pelvis