Techniques for Laparoscopic and LaparoscopicAssisted Biopsy of Abdominal Organs ❯❯ Philipp Mayhew, BVM&S, MRCVS, DACVS Columbia River Veterinary Specialists Vancouver, Washington
At a Glance Patient Preparation and Positioning Page 171
Abdominal Access and Port Positioning Page 171
Liver Biopsy Page 171
Kidney Biopsy Page 173
Gastrointestinal Biopsy Page 173
Pancreatic Biopsy Page 175
Clinical Pearls Page 176
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Abstract: Multiorgan pathology is a common finding during the diagnostic work-up of complex medical diseases in small animals. Collection of cytologic or biopsy samples from several abdominal organs can give the clinician crucial information in guiding therapy. Although many modalities are available for sample collection, laparoscopic and laparoscopic-assisted techniques offer a minimally invasive approach for collection of high-quality biopsy samples from multiple organs during one anesthetic episode. This article discusses the laparoscopic approaches and techniques for multiorgan biopsy in cats and dogs.
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iagnostic evaluation of many different disadvantages versus surgical biopsy techmedical conditions can be assisted by niques.4 Full-thickness intestinal biopsy obtaining biopsy samples from multiple samples cannot be harvested endoscopiabdominal organs. This sample collection has cally, and access to the lower small intestine is not possible with currently available traditionally been performed several ways. “Open” celiotomy has the advantage of endoscopic technology. Some studies allowing thorough inspection of, and easy have shown the limitations of endoscopiaccess to, all abdominal organs. However, it cally collected biopsy samples for diagnosis the most invasive technique, sometimes ing certain conditions (e.g., lymphoma).5,6 necessitating an incision from the xiphoid Flexible endoscopy does, however, have process to the pubis for access to the cranial the advantage of being an outpatient procedure, allowing direct visualization of and caudal abdominal structures. Ultrasound-guided fine-needle aspiration mucosal lesions, and avoiding the reported or needle-core biopsy techniques can be 12% dehiscence rate of full-thickness surgiused for obtaining samples from the liver, cal biopsies.7 pancreas, kidneys, and mesenteric lymph Laparoscopic procedures (performed nodes.1–3 Ultrasound-guided techniques are entirely within the peritoneal cavity) and minimally invasive, but they require a skilled laparoscopic-assisted procedures (which use ultrasonographer, do not allow access to all laparoscopic manipulation to exteriorize organs areas of the peritoneal cavity, and have been for extraperitoneal surgery) can allow a thorshown to produce inferior samples in many ough evaluation of most abdominal organs. cases when compared with open surgical or It is not known whether laparoscopic exploration of the abdominal cavity can be as laparoscopic biopsy techniques.1–3 Flexible gastroscopy and small intestinal thorough as open exploration. However, endoscopy can be used for harvesting gas- almost all abdominal structures are visible tric and small intestinal biopsy samples.4–6 laparoscopically, and the success of laparoThese techniques have advantages and scopic exploration of the peritoneal cavity
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is limited only by the patience of the surgeon. port position depends on which techniques For example, laparoscopic examination of the are to be performed. In most cases, multiple full length of the bowel is possible but time organs can be accessed through a small numconsuming. Another important variable to con- ber of common instrument ports or one small sider is the reliability of preoperative abdomi- “assist” incision (an incision 2 to 4 cm in length nal imaging. In most cases, when preoperative created by enlargement of a previously placed imaging has identified the location of focal instrument port for exteriorization of abdomilesions or when diffuse disease only is sus- nal organs). Before beginning the procedure, pected, the need for laparoscopic visualization the surgeon should decide the minimum comof all organs is debatable. bination of instrument ports that will provide Compared with open celiotomy, a laparo- access to all organs to be biopsied. Usually, scopic approach has been shown to result in less two or three instrument ports are adequate. postoperative pain8 and a faster return to normal activity9 and may result in fewer and less severe Liver Biopsy wound-healing complications. This article pre Due to its fixed location and friable nature, sents some of the technical aspects of harvesting the liver is biopsied using totally laparoscopic biopsy samples using laparoscopic or laparo- techniques. When multiple organ biopsy samscopic-assisted techniques. These techniques ples are needed, the liver sample should be allow clinicians to offer their clients a high like- taken first so that if laparoscopic-assisted prolihood that, similar to open surgery, they will cedures are subsequently performed through obtain high-quality diagnostic samples from larger port incisions, it will not be necessary all the necessary organs during one procedure, to reestablish the pneumoperitoneum for liver when such an approach is clinically indicated. biopsy at the end of the procedure. However, In choosing which diagnostic techniques reinsufflation may be recommended if the surto use, clinicians must balance the desire to geon wishes to confirm adequate hemostasis obtain high-quality biopsy samples from all before completing the surgery. It is wise to the organs in which pathology is suspected in consider performing a full coagulation profile the least invasive way possible against own- before laparoscopic liver biopsy. I place a preers’ financial constraints and tolerance for the tied loop ligature (described below) in animals with coagulopathy or when harvesting large risk of potential complications. samples, although the need or benefit of this Patient Preparation and Positioning practice has not been evaluated scientifically. For all of the techniques described below, the In most cases, when a liver biopsy is perpatient is placed in dorsal recumbency and formed in isolation for diffuse hepatopathy, a sinthe abdomen is liberally clipped from 2 inches gle instrument port suffices. The port is placed cranial to the xiphoid process to the pubis. under direct visualization in a paramedian Laterally, the patient is clipped to approximately the midabdomen level as for a tradiTO LEARN MORE tional open celiotomy. It is important that wide clipping and aseptic preparation be performed in the unlikely event that conversion to an Patient preparation and the Hasson and Veress open procedure becomes necessary. Lateral needle techniques are described in more detail recumbency can be used for access to certain in the August 2008 Surgical Views article, individual organs, but when examination or “Canine Laparoscopic and Laparoscopic-Assisted biopsy of multiple organs is desired, I prefer Ovariohysterectomy and dorsal recumbency and the use of a subumbiliOvariectomy,” available cal telescope port. at CompendiumVet.com.
Abdominal Access and Port Positioning A subumbilical telescope port can be placed using either the Hasson or the Veress needle technique.10 For the following procedures, instrument
QuickNotes Before beginning the procedure, the surgeon should decide the minimum combination of instrument ports that will provide access to all organs to be biopsied.
A video demonstrating the Hasson technique is also available at CompendiumVet.com.
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A needle-core biopsy needle has been placed percutaneously and is inserted into the renal cortex before being discharged. The advantage of the laparoscopic approach is the ability to monitor hemorrhage after withdrawal of the instrument.
QuickNotes In all cases, liver biopsy sites should be visualized until the surgeon is convinced that all hemorrhage has ceased before removing the telescope.
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FIGURE 2
Courtesy of Dr. Mayhew
Courtesy of Philipp Mayhew, BVM&S, MRCVS, DACVS
FIGURE 1
Placement of the wound retraction device produces a small, protected, circular access incision into the peritoneal cavity.
position in either the right or left cranial quad- site with a vessel-sealing device has been rant of the abdomen. Care should be taken not shown in some studies to reduce hemorrhage to place the cannula cranial to the last rib, which associated with the procedure.11,12 risks entering the thoracic cavity and could pre- Several samples can be taken from multiple cipitate pneumothorax. A 6-mm trocar窶田annula lobes. By passing the telescope caudally or craassembly can be placed to accommodate 5-mm nially around the falciform fat, access to both cup biopsy forceps. A second port can be placed right and left sides of the liver is possible. If the on the contralateral side if the surgeon plans to surgeon judges that excessive hemorrhage is use a hemostatic device (vessel-sealing device occurring after liver biopsy, a piece of gelatin or ligature) to harvest the sample. If a focal liver sponge or oxidized regenerated cellulose can lesion has been diagnosed from preoperative be passed through a port and manipulated into imaging, the instrument port should be placed position at the biopsy site to promote clot foron the side of the focal lesion. If other laparo- mation and hemostasis. In all cases, the biopsy scopic procedures are to be performed in addi- sites should be visualized until the surgeon tion to the liver biopsy, the instrument ports is convinced that all hemorrhage has ceased used for those procedures can usually be used before removing the telescope. to access the liver, thus minimizing the number If hemorrhage is of concern (e.g., in animals with advanced hepatic failure, focal or of necessary ports. The simplest way to perform a liver biopsy is highly vascular lesions, or known coagulopaby using 5-mm laparoscopic cup biopsy forceps thies), it may be preferable to apply a pretied to harvest pieces of liver from the edge of a lobe. loop ligature or extracorporeally assembled The tissue is grasped and gently twisted until it loop ligature to ligate the tip of the lobe separates from the rest of the lobe. Care should before taking biopsy samples. This ligation decreases the chance of severe be taken during this process hemorrhage; however, a secto avoid tearing liver parenSURGICAL ond port must be placed for chyma by rough handling, VIDEO application of the ligature. A which can lead to excessive modified Roeder laparoscopic hemorrhage. Performed corTo see videos of a laparoscopic slipﾂｭknot is used. The loop rectly, this technique has liver biopsy using a 5-mm is passed through the instrubeen shown to cause minimal laparoscopic cup forceps, a ment cannula either with the bleeding in healthy dogs and gelatin sponge, and a pretied plastic application device (for to yield good-quality tissue loop ligature, visit commercial pretied loop ligasamples.11,12 Coagulation of CompendiumVet.com. the periphery of the biopsy tures [e.g., Endoloop, Ethicon
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Endosurgery, Cincinnati, OH] ) or with a knot pusher (for self-assembled loop ligatures). It must then be manipulated into position around the tip of a liver lobe. A blunt probe can aid in elevating the liver lobe during loop positioning. When the loop is in position, it is tied by advancing the plastic application device or knot pusher (for self-assembled loops) against the modified Roeder knot until it securely ligates the blood vessels and bile ducts within the parenchyma. The liver tissue distal to the ligature can then be cut with endoscissors and withdrawn through a cannula, or multiple bites can be taken with laparoscopic cup biopsy forceps. If a large focal liver mass is to be biopsied, extreme care should be taken because these lesions are often very vascular. Consideration should be given to taking a needle-core biopsy sample under laparoscopic guidance before collecting larger samples to gauge the level of hemorrhage that will result. Otherwise, a loop ligature should be used to harvest the sample to reduce the risk of profuse hemorrhage. It may be advisable to use a specimen retrieval bag to remove larger samples. Extension of the port site may be needed to recover these samples.
Kidney Biopsy
from the kidney and ensure that hemostasis has been achieved before closure. I prefer to use an automatic spring-activated needle-core biopsy needle to decrease the possibility of inadvertent premature needle withdrawal from the parenchyma that can occur from excessive movement with manually activated Tru-Cut needles. Under direct visualization, the biopsy needle is guided into the parenchyma and directed to pass across the renal cortex to maximize the number of glomeruli recovered13 (Figure 1). The sample is taken by activating the biopsy needle, which is subsequently withdrawn from the peritoneal cavity to recover the sample. Usually, one to two samples are taken from one or both kidneys, depending on the nature of the pathology suspected. If the needle is placed too deeply into the medulla, fewer glomeruli may be recovered and there is a greater risk of hemorrhage from arcuate vessels.13 The laparoscopic technique using a 14-gauge needle has been shown to give superior-quality biopsy samples compared with ultrasonographic guidance of the same-size needle.2
Gastrointestinal Biopsy
Biopsies of the small intestine are usually If a single kidney is to be biopsied, a needle- performed using a laparoscopic-assisted techcore biopsy technique is usually selected. nique. In humans, in which the small intestiTheoretically, no instrument port is required nal lumen is significantly larger, endoscopic for this technique because the biopsy needle stapling devices can be used to resect small can be passed percutaneously into the perito- antimesenteric sections of small intestine. This neal cavity in a location directly ventral and would likely result in excessive compromise of somewhat caudal to the kidney. However, it the luminal diameter in small animals and so is is helpful to have one instrument port avail- not practical in these patients. Exteriorization able for passage of a blunt probe that can of bowel segments through a small assist incihelp manipulate the kidney into position for sion, followed by standard small intestinal the biopsy and place pressure on the biopsy biopsy sample collection from the antimessite after needle withdrawal to minimize hem- enteric border, is usu足ally the best technique in orrhage from the site. This instrument port dogs and cats. can be placed on the ventral A technique for laparomidline 5 to 10 cm cranial scopic-assisted small intesSURGICAL or caudal to the telescope tinal biopsy that involves VIDEO port. If an instrument port is placement of a paramedian available, a piece of oxidized port lateral to the right rectus To see a video of a kidney regenerated cellulose can be abdominis muscle has been biopsy using a 14-gauge placed over the biopsy site reported.14 A 10-mm Babcock spring-loaded needle-core forceps is used to grasp a if hemorrhage is profuse. A biopsy needle and oxidized section of duodenum, jejusignificant benefit of laparosregenerated cellulose, visit num, or ileum and bring it copy is the ability to visualize CompendiumVet.com. to the port-site incision. The the amount of hemorrhage
QuickNotes A significant benefit of laparoscopy is the ability to visualize the amount of hemorrhage from the kidney and ensure that hemostasis has been achieved before closure.
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Large segments of small intestine can be removed through the laparoscopic-assisted incision. Using a wound retraction device minimizes pressure on the mesenteric root, preventing vascular engorgement of exteriorized bowel and facilitating its return to the peritoneal cavity after completion of the biopsy.
QuickNotes There are limitations to the use of small assist incisions for abdominal organ biopsy.
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Courtesy of Dr. Mayhew
FIGURE 4
Courtesy of Dr. Mayhew
FIGURE 3
The duodenum has been partially exteriorized through the assist incision. A biopsy sample can easily be harvested from the duodenum in addition to a pancreatic sample, if clinically indicated.
trocar窶田annula assembly is removed while the device has several advantages. It prevents comBabcock forceps is still grasping the small intes- pression of the mesenteric root and subsequent tinal loop. To exteriorize the loop of intestine, vascular compromise compared with exteriorthe port incision can be enlarged to 2 to 4 cm, ization of the intestine through an unretracted as needed. A sample can then be harvested incision, thereby allowing large sections of in standard fashion. Using this technique, an intestine to be exteriorized for examination at enterostomy feeding tube can also be placed at any one time (Figure 3). It also allows other the time of biopsy, if clinically indicated.14 If a structures such as the pancreas and mesfeeding tube is to be placed, the section of the enteric lymph nodes to be elevated enough small intestine that is grasped must be chosen to easily collect biopsy samples (Figure 4). carefully because duodenostomy and jejunos- If the assist incision is directed cranially from tomy feeding tubes are usually placed in the the original subumbilical port location, it is midduodenal or proximal jejunal areas to opti- usually possible to obtain a sample from the stomach, although this may be challenging in mize nutritional absorption during feeding. I often use a modification of this technique large or deep-chested dogs. The wound retracto allow easier access to the small intestine and tion device also prevents contamination of the other organs. Once any laparoscopic procedures wound margin and has been shown in some (e.g., liver biopsy) are completed, the telescope human studies to decrease wound infection is removed from its subumbilical location and rates.15 Alternatives to the wound retractor the port incision enlarged to 3 to 4 cm to allow device include the placement of Gelpi retractors or a small Balfour retractor placement of a 2- to 4-cm in the wound to open the incilaparoscopic wound retracSURGICAL sion and decrease comprestor (Alexis Wound Retractor, VIDEO sion of the mesenteric root. Applied Medical Corp, Rancho There are limitations to the Santa Margarita, CA). Once the To see videos demonstrating use of small assist incisions retractor is in place, the circumthe placement of a wound for abdominal organ biopsy. ferential force exercised at the retractor and use of this It is difficult to exteriorize the wound margin holds open a device in exteriorizing a large proximal descending duodesmall circular orifice into the section of intestine, visit num and the ileocecocolic peritoneal cavity (Figure 2). CompendiumVet.com. This relatively inexpensive junction. The colon can be
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Once exteriorized, the small intestine can biopsied in standard fashion. The use of a small-gauge stay suture placed at the antimesenteric border, followed by an incision with a number 11 blade, helps in the atraumatic harvesting of small intestinal biopsy samples.
Courtesy of Dr. Mayhew
FIGURE 6
Courtesy of Dr. Mayhew
FIGURE 5
The laparoscopic-assisted technique allows local lavage to be performed in a location away from the opening into the peritoneal cavity, thus minimizing peritoneal contamination.
exteriorized, although full-thickness colonic abdominal incision site, thus preventing any biopsy is strongly discouraged because of the contamination of the peritoneal cavity with high morbidity associated with dehiscence in lavage solution (Figure 6). After completion of this area and the excellent diagnostic quality all procedures, all abdominal wall incision sites can be closed routinely. of colonoscopic biopsy samples.4 With either the modified or unmodified technique, once the intestine is exteriorized, Pancreatic Biopsy samples can be taken using a technique simi- A laparoscopic or laparoscopic-assisted lar to that used during open celiotomy. Using a (Figure 4) technique can be used for pancrestay suture of 4-0 suture material, a small, full- atic biopsy. A single instrument port can be thickness bite is placed on the antimesenteric used for the laparoscopic technique if a punch side of the intestine. A number 11 blade is used technique is used, although a second port is to incise the intestine around the stay suture, necessary if use of a vessel-sealing device or ensuring that an adequate sample of mucosa as ligature is desired. A second instrument port well as submucosa and muscularis is harvested may also be necessary if significant manipula(Figure 5). A skin biopsy punch can also be tion of the surrounding organs is needed to used for small intestinal biopsy sample col- obtain an unobstructed view of the pancreas. lection.16 The incision(s) can be closed using A pancreatic biopsy is usually performed in 3-0 or 4-0 monofilament absorbable suture addition to biopsy of other organs; therefore, material (e.g., polydioxanone) in a simple, access is usually from instrument ports posiinterrupted or simple, continuous suture pat- tioned for these other biopsy procedures. tern. If significant narrow The tip of the right (duoing of the luminal diameter denal) limb of the pancreas SURGICAL is anticipated after suturing, is usually the simplest to VIDEO the incisions can be closed sample. Clinical judgment in transverse fashion to prewill help the surgeon deterserve the luminal diameter mine whether this area will To see a video of pancreatic as much as possible. After provide a representative sambiopsy using a 5-mm cup closure of the biopsy site is ple. A 5-mm cup biopsy forbiopsy forceps, visit complete, local lavage can ceps can be used to carefully CompendiumVet.com. be performed away from the remove a small piece of pan-
QuickNotes The tip of the right (duodenal) limb of the pancreas is usually the simplest to sample.
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Courtesy of Dr. Stephen J. Mehler, DVM, DACVS
FIGURE 7
Clinical Pearls Using a combination of laparoscopic and laparoscopic-assisted techniques, a “one-procedure” approach to collection of high-quality organ samples can be achieved in a minimally invasive fashion. Laparoscopic-assisted techniques can allow several organs to be biopsied through one small port incision.
A laparoscopic biopsy sample is being taken from the periphery of the right pancreatic limb using a 5-mm cup biopsy instrument.
creas from the periphery of the lobe (Figure 7). Care should be taken to avoid performing a biopsy on the body of the pancreas (to avoid damaging pancreatic ducts) or the area where the caudal pancreaticoduodenal vessels enter the tip of the right pancreatic limb. This technique has been shown to be safe in healthy dogs, with no significant clinical abnormalities detected postoperatively, although histologically some inflammation is seen around biopsy sites.17 To reduce hemorrhage, several other techniques can be used. A pretied loop ligature can be placed around a piece of pancreas to be biopsied, or hemostatic clips can be placed in a V-shape around the tissue segment to be excised. A vessel-sealing device can also be used to harvest the sample. A recent study compared use of the Harmonic Scalpel device (Ethicon Endosurgery Inc, Cincinnati, OH) with the placement of hemostatic clips to harvest pancreatic biopsy samples laparoscopically.11 The Harmonic Scalpel led to a reduction in hemorrhage but resulted in significantly greater inflammation.
References
1. Cole TL, Center SA, Flood SN, et al. Diagnostic comparison of needle and wedge biopsy specimens of the liver in dogs and cats. JAVMA 2002;220:1483-1490. 2. Rawlings CA, Diamond H, Howerth EW, et al. Diagnostic quality of percutaneous kidney biopsy specimens obtained with laparoscopy versus ultrasound guidance in dogs. JAVMA 2003;223:317-321. 3. Wang KY, Panciera DL, Al-Rukibat RK, et al. Accuracy of ultrasound-guided fine-needle aspiration of the liver and cytologic findings in dogs and cats: 97 cases (1990-2000). JAVMA 2004;224:75-78. 4. Mansell J, Willard MD. Biopsy of the gastrointestinal tract. Vet Clin North Am Small Anim Pract 2003;33:1099-1116.
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When multiple organ biopsies are required, thought should be given to the optimal position of instrument ports to allow access to all organs in question while minimizing the total number of ports required. When taking a liver biopsy sample, it is my preference to use a loop ligature around the tip of the liver lobe in all animals that are known to have coagulopathy.
Conclusion Laparoscopic and laparoscopic-assisted techniques can be used in combination to gather samples from multiple abdominal organs when diagnostic work-up of complex multiorgan pathology is performed. Even though conversion to an open approach should always be discussed with the owners, in most cases laparoscopic techniques can offer a one-procedure approach for collection of high-quality biopsy samples from multiple organs that is less invasive than open celiotomy.
5. Willard MD, Lovering SL, Cohen ND, et al. Quality of tissue specimens obtained endoscopically from the duodenum of dogs and cats. JAVMA 2001;219:474-479. 6. Evans SE, Bonczynski JJ, Broussard JD, et al. Comparison of endoscopic and full-thickness biopsy specimens for diagnosis of inflammatory bowel disease and alimentary tract lymphoma in cats. JAVMA 2006; 229:1447-1450. 7. Shales CJ, Warren J, Anderson DM, et al. Complications following full-thickness small intestinal biopsy in 66 dogs: a retrospective study. J Small Anim Pract 2005;46:317-321. 8. Devitt CM, Cox RE, Hailey JJ. Duration, complications, stress and pain of open ovariohysterectomy versus a simple method
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of laparoscopic-assisted ovariohysterectomy in dogs. JAVMA 2005;227:921-927. 9. Culp WTN, Mayhew PD, Bown DC. The effect of laparoscopic versus open ovariectomy on post-surgical activity in small dogs. Proc Am Coll Vet Surg Annu Symp 2008. 10. Gower S, Mayhew PD. Canine laparoscopic and laparoscopicassisted ovariohysterectomy and ovariectomy. Compend Contin Educ Pract Vet 2008;30:430-440. 11. Barnes RF, Greenfield CL, Schaeffer DJ, et al. Comparison of biopsy samples obtained using standard endoscopic instruments and the harmonic scalpel during laparoscopic and laparoscopicassisted surgery in normal dogs. Vet Surg 2006;35:243-251. 12. Vasanjee SC, Bubenik LJ, Hosgood G, et al. Evaluation of hemorrhage, sample size, and collateral damage for five hepatic biopsy methods in dogs. Vet Surg 2006;35:86-91. 13. Rawlings CA, Howerth EW. Obtaining quality biopsies of the liver and kidney. JAAHA 2004;40:352-358. 14. Rawlings CA, Howerth EW, Bement S, et al. Laparoscopic-assisted enterosotomy tube placement and full-thickness biopsy of the jejunum with serosal patching in dogs. Am J Vet Res 2002;63:1313-1319. 15. Horiuchi T, Tanishima H, Tamagawa K, et al. Randomized controlled investigation of the anti-infective properties of the Alexis retractor/protector of incision sites. J Trauma 2007;62:212-215. 16. Keats MM, Weeren R, Greenlee P, et al. Investigation of Keyes skin biopsy instrument for intestinal biopsy versus a standard biopsy technique. JAAHA 2004;40:405-410. 17. Harmoinen J, Saari S, Rinkinen M, et al. Evaluation of pancreatic forceps biopsy by laparoscopy in healthy beagles. Vet Ther 2002;3:31-36.
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