Complications of hepatic surgery in companion animals

Evaluating preoperative coagulation panels in dogs undergoing liver lobectomy for primary liver tumors: A multi-institutional retrospective study

BACKGROUND

The objectives of this study were to: (i) Determine whether operable primary liver tumors were associated with prolongations in prothrombin time (PT) and activated partial thromboplastin time (aPTT) and (ii) determine if these secondary hemostatic abnormalities were more prevalent with specific liver tumors.

STUDY DESIGN

Multi-institutional retrospective study.

ANIMAL POPULATION

Dogs (n = 359) undergoing liver lobectomy for a primary liver tumor with a preoperative coagulation panel.

METHODS

Data was identified via electronic medical record review at eight veterinary teaching hospitals. Baseline dog characteristics, coagulation panel values, platelet count, emergency versus non-emergency procedure, whether the dogs received transfusion(s) of a blood product, liver lobe removed, and histopathological diagnosis were extracted from the medical record. Chi-square analysis was used to compare categorical variables between groups. Continuous variables were assessed for normality using the Shapiro-Wilk test.

RESULTS

A total of 74 of 359 dogs (20.6%) had a prolongation in either PT or aPTT preoperatively. A total of 20 of 359 dogs (5.6%) were found to have prolongation of both PT and aPTT. Hemangiosarcoma was the only histopathological diagnosis associated with concurrent prolongations of both PT and aPTT (p < .001) in 6/16 (37.5%) dogs.

CONCLUSION

Coagulation panels including PT and aPTT are unlikely to detect substantial deficiencies in secondary hemostasis in most dogs with primary liver tumors except in dogs with a histopathological diagnosis of hemangiosarcoma.

CLINICAL SIGNIFICANCE

PT and aPTT testing is low yield as an elective preoperative screening test in dogs with primary liver tumors except in dogs where there is a hemoabdomen or high suspicion for hepatic hemangiosarcoma.

Intra- and interobserver agreement in computed tomography localization of primary nonhematopoietic hepatic masses and comparison with surgical and histopathological outcomes in 21 cats

Computed tomography (CT) is commonly used in the staging of hepatic masses and for liver lobectomy planning. Mass location is an important factor in determining the feasibility of resection, including surgical technique and the likelihood of surgical complications. The objectives of this retrospective descriptive cross-sectional, observer agreement, method comparison study were to assess the reliability of CT in correctly determining the hepatic division and lobar site of origin of feline primary nonhematopoietic hepatic masses, compared with surgically confirmed locations. Furthermore, it provides an overview of the types and locations of liver masses found in a cohort of cats. Pre- and postcontrast CT images of 21 cats were independently and simultaneously reviewed by two observers. Intra- and interobserver agreements and descriptive statistics on demographic and histological diagnoses were calculated. Based on surgical assessment, it was found that masses most frequently originated from the left hepatic division (13/24, 54%). The most frequent lobar origins were the left lateral (8/24, 33%), left medial (5/24, 21%), and right medial lobes (5/24, 21%). No masses were found originating from the right lateral lobe. CT correctly determined hepatic division and lobar origin in 76% of cases, with good-to-excellent intra- and interobserver agreement. The hepatic division had higher agreements overall for both observers. Most of the masses were benign (17/21, 81%), and the most prevalent histological diagnoses were biliary cystadenoma (11/21, 52%) and hepatocellular adenoma (6/21, 29%). Findings suggest that postcontrast CT is a reliable method for correctly determining hepatic mass division and lobar origin in cats.

Hepatic lobectomy in dogs using a stapling device with a vascular cartridge: a retrospective study of 13 cases

CASE HISTORY

Medical records of two veterinary hospitals in Canada were reviewed to identify cases of dogs that underwent liver lobectomy via open laparotomy using the Endo GIA surgical stapling device with a vascular cartridge (height of open and closed staples: 2.5 and 1.0 mm, respectively) between January 2016 and June 2018. Mean age at the time of surgery of the dogs (n = 13) included in the study was 10.4 (SD 1.5; min 7.9, max 12.8) years and mean body weight was 14 (min 3.9, max 37.8) kg.

CLINICAL FINDINGS

Liver masses requiring hepatic lobectomy were identified in 12 dogs by abdominal ultrasound examination. The remaining dog required a lobectomy of the right medial liver lobe to address leakage from the right medial lobe hepatic duct that occurred as a complication of cholecystectomy to treat a ruptured gallbladder mucocoele.

TREATMENT AND OUTCOME

Complete liver lobectomy of 14 lobes (11 from the left hepatic division) in 12 dogs and partial lobectomy of one lobe in one dog was performed via open laparotomy using the Endo GIA device. The mean surgical time, including concurrent procedures, was 50 (SD 17; median 45, min 28, max 91) minutes. The most common intra-operative complication was oozing from the transected liver parenchyma in 6/13 dogs, which was mild in all cases. Five dogs experienced minor post-operative complications. No major peri- or post-operative complications occurred, and no patients required surgical re-exploration. All patients survived until discharge and were alive at the 2-week follow-up for suture removal.

CLINICAL RELEVANCE

Use of the Endo GIA stapling device with a vascular cartridge is feasible for liver lobectomy of the left hepatic division and in this study had low rates of intra-operative and post-operative complications. The Endo GIA stapling device is a viable option for this type of liver lobectomy in dogs. Though successful, the small number of central (two lobes) and right (one lobe) hepatic division lobectomies in this study precludes us from drawing definitive conclusions about the feasibility of this technique on these divisions.

Comparative Oncology: Management of Hepatic Neoplasia in Humans and Dogs

Primary hepatic neoplasia is uncommonly reported in dogs. Hepatocellular carcinoma (HCC) is the most frequent neoplasia identified in dogs and considerable effort has been committed towards identifying definitive and palliative treatment options. HCC is well recognized in humans as a sequelae of liver disease such as hepatitis or cirrhosis, while in dogs a similar link has failed to be fully elucidated. Management of HCC in people may be curative or palliative dependent on staging and transplant eligibility. Despite differences in etiology, there is substantial similarity between treatment options for liver neoplasia in human and veterinary medicine. The below summary provides a comparative discussion regarding hepatic neoplasia in dogs and people with a specific focus on HCC. Diagnosis as well as descriptions of the myriad treatment options will be reviewed.

Hemoperitoneum Secondary to Liver Lobe Torsion in a Cat

A 5 yr old male British blue shorthair cat was presented collapsed with hypotension, hypothermia, and cranial abdominal pain. Abdominal ultrasound and abdominocentesis revealed hemoperitoneum and a suspected hepatic mass. Cytology of fine-needle aspirates of the mass was inconclusive, so exploratory celiotomy was performed for diagnostic and therapeutic purposes. An enlarged, hemorrhagic papillary process of the caudate lobe was identified, with twisting of the vasculature at the hilus, so a complete lobectomy was performed using a thoracoabdominal stapler. Histopathology was consistent with liver lobe torsion with no evidence of hepatocellular neoplasia identified. This report describes the first case of hemoperitoneum secondary to liver lobe torsion without evidence of hepatocellular neoplasia in a cat and demonstrates a successful outcome following surgical management with liver lobectomy.

Laparoscopic left hemihepatectomy combined with right lateral hepatic lobectomy in pigs: surgical approach and comparative study of the inflammatory response versus open surgery

This study describes a left hemihepatectomy combined with a right lateral hepatic lobectomy. It compares the inflammatory response associated with laparoscopic hepatectomy (LH group, n = 7) with conventional open hepatectomy (OH group, n = 7). Blood was collected before surgery as well as 1, 2, 3, 5, and 7 days after surgery to determine the white blood cell count and levels of serum cortisol (COR), interleukin-6 (IL-6), and C-reactive protein (CRP). The left hemi-hepatectomy combined with a right lateral hepatic lobectomy was completed in miniature pigs. The average operative time was 139.00 ± 9.07 min, which was longer than that in the OH group (121.67 ± 3.02 min). The length of surgical incision associated with the OH group was 17.93 ± 1.09 cm, significantly longer than that related to the LH group (5.10 ± 0.17 cm). The estimated mean blood loss in the LH group was 136.43 ± 63.24 mL, which was significantly lower than that in the OH group. No severe complications (e.g., massive bleeding, bile leakage, and air embolism) were reported. The CRP levels, COR, and IL-6, increased significantly in the OH group and then slowly returned to their preoperative levels. A postoperative laparoscopic exploration revealed that the incised portion of the liver adhered to the omentum, but no additional abnormalities were observed. These findings indicate that a 4-trocar method for laparoscopic left hemihepatectomy combined with a right lateral hepatic lobectomy is safe and feasible. The inflammatory response for those receiving LH are lower than that for those receiving OH. This porcine model can be used as a research analog for liver disease and regeneration.

Feasibility of laparoscopic liver lobectomy in dogs

OBJECTIVE

To determine the feasibility of laparoscopic liver lobectomy (LLL) in dogs by using canine cadavers and to describe the clinical application in dogs with liver disease.

STUDY DESIGN

Ex vivo experiment and descriptive case series.

SAMPLE POPULATION

Twelve canine cadavers and six client-owned dogs.

METHODS

Cadavers underwent LLL with an endoscopic stapler. The percentage of liver lobe resected was determined by volume. The distance from the staple line to hilus was measured. Medical records of dogs undergoing LLL were reviewed.

RESULTS

In cadavers ≤15 kg, left lateral lobectomy completeness was 87.3% (84.6%-96.6%), and remaining median (interquartile range) hilar length was 1 cm (0.25-1.75). Left medial lobectomy completeness was 72.5% (66.7%-80%), and remaining hilar length was 1.6 cm (0.47-1.75). Central division resection completeness was 68.3% (60%-92.9%), and remaining hilar length was 2.7 cm (0.8-5). Laparoscopic liver lobectomy was not feasible for right division lobes and in cadavers >15 kg. Five dogs with peripheral quadrate or left lateral lobe masses underwent stapled, partial laparoscopic lobectomy (30%-90%). One dog underwent stapled, left lateral lobectomy (90%) after open procedure conversion. Histopathological diagnoses included hepatocellular carcinoma (3), nodular hyperplasia (1), biliary cyst adenoma (1), and fibrosis (1).

CONCLUSION

Laparoscopic liver lobectomy of the left and central divisions is feasible in cadavers ≤15 kg with an endoscopic stapler. Partial LLL of the left and central divisions is feasible in select dogs with liver disease.

CLINICAL SIGNIFICANCE

Laparoscopic liver lobectomy may be a viable alternative to laparotomy in small-to-medium size dogs with peripheral liver masses of the left and central divisions.

Use of a cavitron ultrasonic surgical aspirator for parenchyma-sparing and complex liver resections in dogs

OBJECTIVE

To report the clinical use of a cavitron ultrasonic surgical aspirator (CUSA) for the resection of hepatic lesions in dogs.

STUDY DESIGN

Clinical prospective study.

ANIMALS

Eleven client-owned dogs.

METHODS

Dogs requiring a hepatic nodulectomy, segmentectomy, and/or a lobectomy (including complex lobectomies) were enrolled. The number and location of procedures, blood loss, duration of surgery, and short-term complications were recorded.

RESULTS

Dogs underwent a mean of 2.3 ± 1.1 procedures. All masses were amenable to surgical excision regardless of their location and their relationship with major hepatic vessels. Dogs lost a median of 77 mL of blood (9.9-161), which corresponded to 4.3% of blood volume (0.8%-23.2%). The dog with the highest blood loss survived without requiring transfusion. The median duration of all CUSA procedures was 33.5 minutes (15-82). Short-term outcomes were assessed for the first 15 days, during which two complications were diagnosed. Cholangiohepatitis was diagnosed in one dog and resolved after medical management, and another dog developed necrotic pancreatitis and died.

CONCLUSION

Liver parenchyma-sparing nodulectomies and segmentectomies and liver lobectomies including complex lobectomies were achieved with a CUSA in all dogs.

CLINICAL SIGNIFICANCE

Use of a CUSA can be considered as an alternative for the removal of hepatic lesions in dogs.

Ability of positive and negative contrast computed tomographic peritoneography to delineate canine liver lobe fissures

OBJECTIVE

To determine the efficacy of contrast peritoneography in delineating liver lobe fissures by using computed tomography (CT).

STUDY DESIGN

Prospective cross-sectional study.

ANIMALS

Canine cadavers (n = 10).

METHODS

An abdominal CT image of each cadaver was obtained under three conditions: without peritoneal contrast (precontrast), after insufflation of the peritoneal cavity with CO₂ (negative contrast), and after intraperitoneal administration of iohexol (positive contrast). Images were reconstructed in three planes. Three reviewers independently scored each plane/contrast combination. Observers measured the length of each fissure in each plane. The measurable length of fissures was compared between techniques but was not compared with the actual length on cadavers.

RESULTS

When assessment of all fissures was combined, measurements were obtained in 96 to 108 of 120 (80%-90%) positive contrast studies, 56 to 96 of 120 (47%-80%) negative contrast studies, and 12 to 32 of 120 (10%-27%) precontrast CT images. All observers measured fissures in all planes that were approximately two times longer on positive compared with negative contrast studies and two times longer on negative contrast studies compared with CT images without contrast. Measurable fissure lengths were greater on positive contrast CT images (P < .0001) than on other CT images.

CONCLUSION

Positive contrast CT peritoneography improved the delineation of hepatic interlobar fissures in normal canine cadavers.

CLINICAL SIGNIFICANCE

These results justify further studies to determine the ability to locate large hepatic masses in dogs with positive CT. Positive contrast CT peritoneography may assist treatment planning in dogs with large hepatic tumors.

Ultrasonographic and CT accuracy in localising surgical- or necropsy- confirmed solitary hepatic masses in dogs

OBJECTIVES

To estimate the sensitivity and specificity of ultrasound and CT for localising solitary hepatic masses to particular liver divisions.

MATERIALS AND METHODS

Dogs diagnosed with a solitary liver mass by ultrasound and/or CT, with surgical or necropsy confirmation within 1 month of imaging. Ultrasound reports were reviewed for mass location. CT scans were reviewed by two radiologists and mass location was determined by consensus agreement. Sensitivity and specificity were calculated for ultrasound and CT for each liver division.

RESULTS

Fourteen of 71 dogs had CT only, 27 of 71 had ultrasound only and 30 of 71 had both. Location was correctly predicted in 42 of 57 dogs (74%) by ultrasound and in 37 of 44 dogs (84%) by CT. Both CT and ultrasound had high specificity for localising masses in all divisions. Sensitivity varied among divisions and was highest for left division masses.

CLINICAL SIGNIFICANCE

The results suggest that either imaging modality is appropriate for presurgical planning. Prospective studies are recommended to help identify additional factors that may aid in determination of hepatic mass location.

Incidence of blood transfusion requirement and factors associated with transfusion following liver lobectomy in dogs and cats: 72 cases (2007-2015)

OBJECTIVE To determine the incidence of blood transfusion, mortality rate, and factors associated with transfusion in dogs and cats undergoing liver lobectomy. DESIGN Retrospective case series. ANIMALS 63 client-owned dogs and 9-client owned cats that underwent liver lobectomy at a specialty veterinary practice from August 2007 through June 2015. PROCEDURES Medical records were reviewed and data extracted regarding dog and cat signalment, hematologic test results before and after surgery, surgical method, number and identity of lobes removed, concurrent surgical procedures, hemoabdomen detected during surgery, incidence of blood transfusion, and survival to hospital discharge (for calculation of mortality rate). Variables were compared between patients that did and did not require transfusion. RESULTS 11 of 63 (17%) dogs and 4 of 9 cats required a blood transfusion. Mortality rate was 8% for dogs and 22% for cats. Pre- and postoperative PCV and plasma total solids concentration were significantly lower and mortality rate significantly higher in dogs requiring transfusion than in dogs not requiring transfusion. Postoperative PCV was significantly lower in cats requiring transfusion than in cats not requiring transfusion. No significant differences in any other variable were identified between dogs and cats requiring versus not requiring transfusion. CONCLUSIONS AND CLINICAL RELEVANCE Dogs and cats undergoing liver lobectomy had a high requirement for blood transfusion, and a higher requirement for transfusion should be anticipated in dogs with perioperative anemia and cats with postoperative anemia. Veterinarians performing liver lobectomies in dogs and cats should have blood products readily available.

Hepatobiliary Neoplasia

Older companion animals may be uncommonly affected with hepatobiliary neoplasia. If clinical signs are shown they are often nonspecific. Animals may have increased liver enzyme activities detected on serum biochemistry. Ultrasound imaging can help to characterize liver lesions and guide sampling with fine needle aspiration. Treatment for massive liver tumor morphology involves liver lobectomy. Prognosis depends on the tumor morphology, type, and stage, but can be good for cats and dogs with massive hepatocellular tumors, with animals experiencing prolonged survival and low recurrence rates.

Serum C-reactive protein and S100A12 concentrations in dogs with hepatic disease

OBJECTIVES

To describe serum C-reactive protein and S100A12 concentrations in dogs with hepatic disease and to determine whether there is a relationship between the concentration of either and the severity of hepatic necroinflammation.

METHODS

Serum C-reactive protein and S100A12 concentrations were measured in 46 dogs undergoing hepatic biopsy. Dogs were divided into three groups: congenital portosystemic shunts, chronic hepatitis and hepatic neoplasia. The histological severity of hepatic necroinflammation was scored.

RESULTS

C-reactive protein and S100A12 concentrations were greater than the upper limit of the reference intervals in 39 and 26% of dogs, respectively. There was no association of disease group with C-reactive protein (P=0·1733) or S100A12 (P=0·1513) concentrations. There was a positive correlation between serum C-reactive protein concentration and hepatic necroinflammatory activity (rs =0·428, P=0·006).

CLINICAL SIGNIFICANCE

Increased serum C-reactive protein and S100A12 concentrations were observed in a subpopulation of dogs with various types of hepatic diseases, suggesting acute-phase inflammation and activation of phagocytic cells, respectively. Dogs with higher hepatic necroinflammatory activity scores tended to have higher serum C-reactive protein concentrations. Further studies are needed to confirm this finding in a larger group of dogs.

Current concepts in hepatobiliary surgery

The most common hepatic procedures performed in companion animals are liver biopsies and partial hepatectomies. Surgery of the biliary tract most often involves the gallbladder, although surgical intervention of the bile duct may also be performed. Hepatobiliary surgery is often challenging, being performed in patients with significant systemic illness and associated with potentially life-threatening complications. An in-depth understanding of the regional anatomy, use of a team concept for patient management, particularly for patients undergoing partial hepatectomy surgery, and provision of intensive perioperative monitoring and support helps minimize complications and maximize outcome.

Laparoscopic left hepatectomy in swine: a safe and feasible technique

A purely laparoscopic four-port approach was created for left hepatectomy in pigs. A polyethylene loop was placed on the left two hepatic lobes for traction and lift. Next, penetrating ligation of the lobes using of a double row of silk sutures was performed to control bleeding. A direct hepatic transection was completed using a monopolar hook electrode without meticulous dissection of the left hepatic vein. The raw surface of the liver was coagulated and sealed with fibrin glue. Lobes were retrieved through an enlarged portal. Laparoscopic hepatic lobectomy was completed in all pigs without the use of specialized instruments and with a mean operative time of 179 ± 9 min. No significant perioperative complications were observed. The average weight of each resected lobe was 180 ± 51 g. Complete blood count as well as serum organics and enzyme levels normalized after about 2 weeks. During necropsy, adhesion of the hepatic raw surface to the gastric wall and omentum were observed. No other abnormalities were identified. This minimally invasive left hepatectomy technique in swine could serve as a useful model for investigating liver diseases and regeneration, and offer preclinical information to improve hepatobiliary surgical procedures.