No Such Thing As Negative Exploratory

You may have heard this saying: “If you don’t have negative exploratory laparotomies, you’re not doing enough of them.”

The idea is to encourage practitioners to recommend abdominal surgery on patients who don’t have a definitive diagnosis quite yet. For example, a patient could have unexplained vomiting or a suspicion of foreign body ingestion.

“Take this patient to surgery,” goes the advice, “because the risks of procrastinating outweigh the risks of missing a correctable condition.”

In other words, a negative exploratory laparotomy is acceptable.

Well, this columnist humbly disagrees.

Systematic Approach

 We have already discussed the art of performing a thorough exploratory laparotomy [“Secrets of a Successful Exploratory Laparotomy,” February 2008]. Missing a foreign body, enlarged lymph nodes or distended gallbladder is avoided by following a systematic approach. Making an abdominal incision that is long enough is also critical. This will allow careful observation and palpation of the liver cranially, the bladder caudally, and all organs in between.

Still, there should be no such thing as a negative exploratory. If you don’t find anything grossly abnormal or fixable or removable, then you should at least take some biopsies and submit them to the lab. Of course, saying “you should” is a diplomatically correct way to say that you must.

When should we consider an exploratory laparotomy? By definition, when we are not 100 percent convinced of the diagnosis. Arguably, this could be when a patient presents with:

  • Unexplained and unresolved melena.
  • Chronic weight loss of unknown origin.
  • A history of eating foreign bodies (especially with puppies and kittens).
  • A questionable barium study.
  • A penetrating injury to the abdomen, such as a gunshot wound.
  • Unexplained and unresolved gastric dilatation or intestinal distension even with no radiographic or ultrasonographic evidence of obstruction.
  • A focal intestinal lesion seen on ultrasound, such as a mass.
  • An increase in bilirubin without a logical explanation.
  • When partial-thickness GI biopsies taken via endoscopy do not provide answers that may be provided by full-thickness GI biopsies performed surgically.

If You Don’t Follow Up

What are the consequences of closing a patient after a negative exploratory without taking and submitting biopsies?

Here is how Candace Carter, DVM, Ph.D., Dipl. ACVIM, an internist at Valley Central Veterinary Referral Center in Whitehall, Pa., answered the question:

  1. We (still) cannot document whether there is gastrointestinal or some other abdominal disease.
  2. The patient, who may (still) be debilitated, may need to have another anesthetic episode to have endoscopic or surgical biopsies harvested.
  3. You may need to admit to a disgruntled internist or surgeon that you didn’t take biopsies!
  4. You need to have the same tricky discussion with an unhappy client.

Convinced? There are many ways to perform such biopsies, so let’s go through a few basic options.

Liver Biopsies


Photo by Dr. Phil Zeltzman.

Liver biopsies are indicated if there is a clear suspicion of liver disease, a possibility of metastasis or a lesion is visible. In some cases, the liver can look normal to the naked eye but reveal the diagnosis upon a histopathologic exam

Liver biopsies are indicated if there is a clear suspicion of liver disease, a possibility of metastasis or a lesion is visible. In some cases, the liver can look normal to the naked eye but reveal the diagnosis upon a histopathologic exam (see photo).

Recent, real-life examples at our practice include generalized abdominal lymphoma and hepatic microvascular dysplasia.

Liver biopsies can be performed using the guillotine technique. The tip of a representative liver lobe is encircled with an absorbable ligature. As the knot is tightened, it cuts through the parenchyma but ligates the blood vessels and bile ducts. Similar results can be achieved by first placing a hemostat around the tip of a liver lobe, then tightening a ligature distal to it. The biopsy sample is harvested using Metzenbaum scissors or a scalpel blade.

Pancreatic Biopsies

Pancreatic biopsies scare many people, but they can be performed with little morbidity by being gentle and following simple guidelines. The concern is that taking a biopsy may cause inflammation and worsen the symptoms.

One biopsy technique is very similar to the guillotine method described above. As the suture material is tightened, it cuts through the parenchyma but ligates the blood vessels and pancreatic ducts.

Gastric Biopsies


Photo by Dr. Phil Zeltzman.

A full-thickness biopsy is taken in a stomach area not too vascularized.

Relying on visual inspection of the GI tract can be misleading. Please remember that even the greatest surgeons don’t have microscopic vision.

Most of the time, gastrointestinal biopsies are recommended for a vomiting patient.

If the stomach looks and feels within normal limits, then a full-thickness biopsy is taken in an area not too rich in blood vessels, typically midway between the lesser and the greater curvatures. Stay sutures can be placed to facilitate biopsying and suturing as well as to prevent leakage.

A stab incision is made using a scalpel blade, and Metzenbaum scissors are used to harvest a full-thickness biopsy. The defect is sutured with full-thickness absorbable suture material, such as polydioxanone, using either a simple interrupted or a Cushing’s pattern. A taper needle is preferred.

Intestinal Biopsies

The technique is the same whether intestinal biopsies involve the duodenum, the jejunum or the ileum. In fact, all three levels should be ideally biopsied. At the very least, the jejunum should be sampled.

Keep in mind that when we do this, we submit a fragment of tissue that measures a few millimeters to represent an organ that measures several feet!

There are several ways to take intestinal biopsies. Which one is best? Probably the one you are comfortable with. Again, full-thickness biopsies are critical.

One technique involves harvesting a small (2- to 3-mm-long) longitudinal, elliptical incision along the anti-mesenteric border of the intestine.

Depending on the size of the patient, suturing the defect longitudinally may reduce the intestinal lumen significantly. Therefore, the incision can be sutured transversally, thereby increasing the diameter of the biopsy site.

An appositional, full-thickness, simple interrupted suture pattern is used, for example with 3-0 or 4-0 absorbable suture material.

Mesenteric Lymph Nodes

If mesenteric lymph nodes appear enlarged, a wedge biopsy can be taken using a 15 or 11 scalpel blade. Closing the defect with simple interrupted sutures or a cruciate pattern is sufficient to provide hemostasis.

Once a sample has been harvested, it should be placed in a biopsy jar quickly with a formalin volume 10 times larger than the biopsy. Those tiny biopsy samples should be handled carefully to avoid crushing artifacts.

You may want to practice these biopsy techniques on a few cadavers to become comfortable with the concept. Once you have practiced a few times, you will enjoy much happier laparotomies.

So please do the right thing. Next time you face a negative exploratory, at least give your patient and your client the benefit of biopsies. Don’t come out empty-handed.


Phil Zeltzman is a board-certified mobile surgeon in Allentown, Pa. His website is

This article first appeared in the March 2010 issue of Veterinary Practice News


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