Complications and outcomes associated with laparoscopic-assisted splenectomy in dogs

Marissa E. S. McGaffey Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada

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Ameet Singh Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada

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Nicole J. Buote Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY

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Philipp D. Mayhew Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA

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Nicole Rupnik Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA

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Federico Massari DOCVET Clinica Veterinaria Nervianese, Nerviano, Italy

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J. Brad Case Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL

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Boel A. Fransson Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA

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Michelle L. Oblak Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada

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Brigitte A. Brisson Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada

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Jacqueline E. Scott Illinois Veterinary Teaching Hospital, College of Veterinary Medicine, University of Illinois, Urbana, IL

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Victoria A. Donovan Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada

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Ryan Appleby Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada

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Gabrielle Monteith Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada

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Abstract

OBJECTIVE

To report the perioperative characteristics and outcomes of dogs undergoing laparoscopic-assisted splenectomy (LAS).

ANIMALS

136 client-owned dogs.

PROCEDURES

Multicentric retrospective study. Medical records of dogs undergoing LAS for treatment of naturally occurring splenic disease from January 1, 2014, to July 31, 2020, were reviewed. History, signalment, physical examination and preoperative diagnostic test results, procedural information, complications, duration of hospitalization, histopathologic diagnosis, and perioperative outcomes were recorded. Perioperative complications were defined using the Veterinary Cooperative Oncology Group – Common Terminology Criteria for Adverse Events (VCOG-CTCAE v2) guidelines.

RESULTS

LAS was performed for treatment of a splenic mass (124/136 [91%]), immune-mediated disease (7/136 [5%]), splenomegaly (4/136 [3%]), or immune-mediated disease in conjunction with a splenic mass (1/136 [1%]). Median splenic mass size was 1.3 cm3/kg body weight. Conversion to open laparotomy occurred in 5.9% (8/136) of dogs. Complications occurred in 78 dogs, with all being grade 2 or lower. Median surgical time was 47 minutes, and median postoperative hospital stay was 28 hours. All but 1 dog survived to discharge, the exception being postoperative death due to a suspected portal vein thrombus.

CLINICAL RELEVANCE

In the dogs of this report, LAS was associated with low rates of major complications, morbidity, and mortality when performed for a variety of splenic pathologies. Minimally invasive surgeons can consider the LAS technique to perform total splenectomy in dogs without hemoabdomen and with spleens with modest-sized splenic masses up to 55.2 cm3/kg, with minimal rates of complications, morbidity, and mortality.

Abstract

OBJECTIVE

To report the perioperative characteristics and outcomes of dogs undergoing laparoscopic-assisted splenectomy (LAS).

ANIMALS

136 client-owned dogs.

PROCEDURES

Multicentric retrospective study. Medical records of dogs undergoing LAS for treatment of naturally occurring splenic disease from January 1, 2014, to July 31, 2020, were reviewed. History, signalment, physical examination and preoperative diagnostic test results, procedural information, complications, duration of hospitalization, histopathologic diagnosis, and perioperative outcomes were recorded. Perioperative complications were defined using the Veterinary Cooperative Oncology Group – Common Terminology Criteria for Adverse Events (VCOG-CTCAE v2) guidelines.

RESULTS

LAS was performed for treatment of a splenic mass (124/136 [91%]), immune-mediated disease (7/136 [5%]), splenomegaly (4/136 [3%]), or immune-mediated disease in conjunction with a splenic mass (1/136 [1%]). Median splenic mass size was 1.3 cm3/kg body weight. Conversion to open laparotomy occurred in 5.9% (8/136) of dogs. Complications occurred in 78 dogs, with all being grade 2 or lower. Median surgical time was 47 minutes, and median postoperative hospital stay was 28 hours. All but 1 dog survived to discharge, the exception being postoperative death due to a suspected portal vein thrombus.

CLINICAL RELEVANCE

In the dogs of this report, LAS was associated with low rates of major complications, morbidity, and mortality when performed for a variety of splenic pathologies. Minimally invasive surgeons can consider the LAS technique to perform total splenectomy in dogs without hemoabdomen and with spleens with modest-sized splenic masses up to 55.2 cm3/kg, with minimal rates of complications, morbidity, and mortality.

Introduction

Splenectomy is the treatment of choice for several disorders of the spleen in dogs, including, but not limited to, benign and malignant neoplasia, torsion, hematoma, rupture, infiltrative, and immune-mediated disease.15 The surgical approach in dogs most commonly involves a ventral midline laparotomy,6 however, total laparoscopic and laparoscopic-assisted techniques for splenectomy have been described and are performed with increasing frequency.4,79 Reported advantages of laparoscopic and laparoscopic-assisted splenectomy (LAS) over ventral midline laparotomy include decreased signs of postoperative pain, shortened hospitalization times, and decreased blood loss.4,8,10,11

Case selection remains of vital importance for the surgical success of total laparoscopic and laparoscopic-assisted splenectomy. Single and multi-port techniques have been described for total laparoscopic splenectomy in dogs.2,8,11 A recent study has suggested that single-port total laparoscopic splenectomy be limited to dogs < 20 kg with splenic masses < 3 to 4 cm in diameter.9 Another study reported multi-port total laparoscopic splenectomy was successful in dogs with naturally occurring splenic disease, in the absence of hemoabdomen or massive splenectomy.11

A LAS technique was described previously by Wright et al4 and was designed to expand the population of dogs that could undergo minimally invasive splenectomy. In this technique, initial laparoscopic evaluation is performed using a single or multi-port technique, followed by creation of a mini-laparotomy access incision approximately the size of the splenic mass or lesion. A wound retraction device (WRD) is inserted into the access incision and the spleen is then digitally grasped and progressively exteriorized through the WRD to allow for extracorporeal vessel sealing of the splenic hilum and any associated omental adhesions. This LAS technique was found to have short surgical times, a minimal complication rate, and was applied to a wide range of dog breeds with larger-sized splenic masses that may not be amenable to total laparoscopic splenectomy, effectively expanding the number of dogs that can undergo minimally invasive splenectomy.4

The objective of this report is to retrospectively describe perioperative outcomes in a large cohort of dogs undergoing LAS. We hypothesized that LAS is a suitable technique for splenectomy in a wide range of dog weights and splenic mass sizes and will be associated with a low high-grade complication rate.

Materials and Methods

Case selection and medical records review

A medical record search of dogs undergoing LAS between January 1, 2014, and July 31, 2020, at 6 academic veterinary hospitals and 2 private practice referral hospitals was performed. Preoperative data collected included history, age, breed, physical examination, and diagnostic test results; intraoperative data collected included operative details and surgical time, results of abdominal exploration, concurrent surgical procedures, and complications; postoperative data collected included duration of hospitalization, histopathologic diagnosis, perioperative complications, and outcomes. Perioperative complications were defined using the VCOG-CTCAE v2 guidelines.12 The perioperative period was defined as the time from hospital admission for LAS until discharge or death within the same visit. Only dogs with complete medical records that underwent LAS during this time period were included in the study.

In dogs with splenic masses, splenic mass volume was calculated when available via mass radius or via length, width, and height, as measured on imaging. Splenic mass volume was expressed in a ratio of mass volume in centimeters3 to body weight in kilograms, as was previously reported to account for variation in dog size.1

Surgical technique

Laparoscopic abdominal exploration and staging—In selected cases, and according to surgeon preference, either a single-port or multi-port technique was used to perform laparoscopic abdominal exploration and staging. Single-port laparoscopic evaluation was performed using the technique described by Case and Ellison in 2013,13 while multi-port laparoscopic evaluation was performed as described by Wright et al.4 In brief, dogs were anesthetized, placed in dorsal recumbency, and their ventral abdomen aseptically prepared for surgery. For single-port laparoscopic evaluation either a single incision, multichannel port (SILS Port; Medtronic) was inserted into the abdomen as described by Case and Ellison13 or a laparoscopic access device (GelPort Laparoscopic System; Applied Medical) was inserted into the abdomen as previously described.4 For multi-port laparoscopy, a 6-mm smooth or threaded trocar and cannula assembly (Karl Storz Endoscopy) was inserted in a subumbilical location.4 The peritoneal cavity was insufflated with carbon dioxide to 8 to 10 mm Hg, and laparoscopic intracorporeal evaluation commenced in the single-port group, while 1 to 2 instrument portals were introduced in the multi-port group prior to laparoscopic abdominal exploration.

Laparoscopic-assisted splenectomy—All apparatus were removed, and the abdomen was evacuated of CO2. A mini-laparotomy access incision was created by extending the subumbilical incision to the approximate size of the anticipated splenic lesion, and a WRD introduced.4 In dogs where a laparoscopic access device was used, incision extension and wound retractor placement was not required as it was a component of the initial laparoscopic access.

Splenectomy was performed by digitally grasping the tail of the spleen through the WRD and progressively exteriorizing it as a vessel-sealing device was used to progressively seal and transect the splenic hilus and any omental adhesions. All spleens were submitted for histopathologic evaluation.

In selected cases, extracorporeal gastrointestinal exploration was performed following LAS, with the jejunum digitally grasped, exteriorized through the WRD and isolated with moistened laparotomy sponges, and then examined in the orad and aborad directions to the caudal duodenal flexure and ileocecocolic junction, respectively. Following completion of laparoscopic abdominal exploration, staging procedures, LAS, and any concurrent intra- or extracorporeal abdominal procedures, the mini-laparotomy access incision and any instrument portals were closed in a routine fashion.

Concurrent procedures—Abdominal intracorporeal concurrent procedures were performed following abdominal exploration and laparoscopic staging. Adjunctive thoracic procedures (intracorporeal, extracorporeal, or both) were performed prior to or following laparoscopic abdominal exploration and LAS according to attending surgeon discretion.

Adverse event and complication classification

The definitions used to describe adverse events and surgical complications were obtained from Follette et al,14 where adverse events were defined as “any unfavorable and unintended incident, sign, or disease temporally associated with the use of a medical treatment that may or may not be attributed to the treatment”, and surgical complications were defined as “an adverse event temporally associated with and attributed to surgical intervention.” Both adverse events and surgical complications were classified whenever possible using the updated VCOG-CTCAE v2 guidelines, being assigned both a category and severity.12

Postoperative care

All dogs were monitored and received supportive care in hospital postoperatively until time of discharge. Timing of discharge, postoperative treatments including methods of analgesia, and follow-up recommendations were according to the discretion of the attending clinician.

Statistical analysis

Descriptive statistics including a measure of central tendency (median) and dispersion (range) were calculated for dog age, weight, splenic mass radius and splenic mass volume, and splenic mass volume per kilogram body weight. Splenic mass volume was then expressed as volume per kilogram bodyweight for comparison purposes and further descriptive statistics calculated (median, and range). Numbers and percentages were used to report all categorical variables (sex, reason for splenectomy, etc). Exact univariate conditional logistic regression was used to determine risk factors for conversion. The continuous parameters analyzed included age, body weight, mass radius, mass volume, total solids, PCV, surgery and anesthesia time. Ordinal factors analyzed included CBC and serum biochemical profile. The data distribution was checked for normality using the Shapiro Wilk test. Median and range were reported for summary statistics. P values of <0.05 were considered statistically significant. Statistical analyses were performed using standard software (SAS version 9.4; SAS Institute Inc).

Results

Study population

One hundred thirty-six dogs met the inclusion criteria. The median age was 123.5 months (range, 36 to 224 months), and the median weight was 23.35 kg (range, 4 to 55 kg). Castrated male dogs (57/136) were most common, followed by spayed females (51/136), sexually intact males (6/136), sexually intact females (1/136), and dogs with unknown sex or neuter status (21/136).

Preoperative diagnostic tests

Reported preoperative diagnostic workup included 1 or more of the following: a CBC (124/136), serum biochemical profile (126/136), thoracic radiography (124/136), abdominal ultrasonography (126/136), CT (29/136), or MRI (2/136). Regions evaluated with CT included the abdomen (15/136), thorax (1/136), both thorax and abdomen (8/136), shoulder (1/136), head (3/136), and both thorax and shoulder (1/136). The 2 cases in which MRI was employed were limited to imaging of the brain. All dogs received diagnostic imaging of at least 1 modality, and all but 2 dogs received abdominal imaging via ultrasonography or CT. The method of splenic mass diagnosis performed prior to referral was not reported in 2 dogs.

Reason for splenectomy

The most common reason for splenectomy was identification of 1 or more splenic masses or nodules on preoperative diagnostic testing (124/136). Alternate reasons included treatment of immune-mediated disease in the absence of a splenic mass (7/136), diffuse splenomegaly (4/136), and for treatment of immune-mediated disease with a concurrent splenic mass (1/136).

Splenic mass size

Splenic masses identified on abdominal ultrasonography or CT were measured in 86 of the 136 dogs. The median radius was 1.85 cm (range, 0.3 to 7.5 cm) with a corresponding median volume of 26.5 cm3 (range, 0.1 to 1767.1 cm3). Expressed as volume per kilogram body weight, the median volume/kg was 1.6 cm3/kg (range, 0.01 to 55.2 cm3/kg).

Surgical approach and concurrent procedures

A single-port technique for initial laparoscopic evaluation was performed in 80% of dogs (109/136), a multi-port technique was used in 17.6% of dogs (24/136) and was unspecified in 3 dogs. In dogs undergoing a single-port technique, the SILS Port was used in 73.5% (100/136) and a Gelport in 1.5% (2/136). The type of port used was not reported in the remaining 5% (7/136) dogs undergoing a single-port technique.

One hundred eighteen dogs undergoing LAS received concurrent procedures. Seventy-five dogs had 1 additional procedure performed, 31 dogs had 2 additional procedures, 9 dogs had 3 additional procedures, and 3 dogs had 4 additional procedures performed. The most commonly performed additional procedure was laparoscopic liver biopsy, which was performed in 110 of the 136 (80.9%) dogs. Concurrent open abdominal procedures included gastrointestinal biopsies (5/136), omental mass biopsy (2/136), partial pancreatectomy (1/136), a liver lobectomy (1/136), right adrenalectomy (1/136), an unspecified intraabdominal mass removal (1/136), and an ovariectomy (1/136). Additional total laparoscopic procedures included peritoneal biopsy (3/136), left adrenalectomy (2/136), cholecystectomy (1/136), gastropexy (1/136), medial iliac lymph node biopsy (1/136), and kidney biopsy (1/136). Two thoracoscopic concurrent procedures were performed; a subtotal pericardiectomy (2/136) and a caudal tracheobronchial lymphadenectomy (1/136). Total lung lobectomies were performed in 4 of the 136 dogs: 3 using a thoracoscopic-assisted technique and 1 via open thoracotomy. Cutaneous masses were removed in a total of 17 of the 136 dogs. Lymphadenectomies were performed in 9 of the 136 dogs, including mesenteric (2/136), left and right medial retropharyngeal (1/136), the left retropharyngeal (1/136), cervical (1/136), sublumbar (1/136), tracheobronchial (1/136), bilateral inguinal (1/136), and an unspecified lymph node (1/136). Other procedures included a left thyroidectomy (n = 3), partial rostral mandibulectomy (1/136), vaginal mass biopsy (1/136), left anal sacculectomy (1/136), neuter (1/136), right thoracic limb amputation (1/136), and microwave ablation of hepatic nodules (1/136).

Conversion to laparotomy and complications

The LAS approach was converted to an open laparotomy in 5.9% (8/136) of dogs. A hemoabdomen was present in 3 dogs upon entry to the abdomen and conversion was performed. Other causes for conversion included iatrogenic splenic mass rupture and subsequent hemorrhage during intracorporeal manipulation (2/136), iatrogenic hemorrhage during hilar vessel sealing (1/136), difficulty exteriorizing spleen with concern for potential mass rupture (1/136), and identification of a hepatic mass for which lobectomy was performed (1/136).

Complications occurred in 57.3% (78/136) of dogs between anesthetic induction and discharge (Figure 1). A total of 134 complications were documented in the 136 dogs, the majority being secondary to anesthesia (46/134 [34%]), and 17% (23/134) intraoperative. All complications were non–life-threatening and resolved spontaneously or with appropriate intervention.

Figure 1
Figure 1

Frequency distribution of the types of complications occurring between anesthetic induction and hospital discharge or death for 136 client-owned dogs undergoing laparoscopic-assisted splenectomy between January 1, 2014, and July 31, 2020, at any of 8 participating facilities grouped by grade (grade 1, 2, or not reported).

Citation: Journal of the American Veterinary Medical Association 260, 11; 10.2460/javma.21.12.0536

Surgical time for abdominal exploration, laparoscopic staging, LAS, and any concurrent procedures was reported for 118 dogs, the median being 47 minutes (range, 12 to 210 minutes). Anesthesia time was reported in 135 dogs, with a median total anesthesia time being 115 minutes (range, 60 to 360 minutes). In the 18 dogs solely undergoing LAS the median surgical and anesthesia times were 35 and 90 minutes respectively (range, 12 to 80 minutes and 60 to 178 minutes, respectively). In 70 dogs that underwent LAS and laparoscopic liver biopsies the median surgical and anesthesia times were 45.5 (range, 15 to 150 minutes) and 100 (range, 63 to 257 minutes), respectively. Ninety-nine percent of dogs survived to hospital discharge (135/136). One dog died suddenly in the hospital, 19 hours postoperatively, of a presumed portal vein thrombus. This presumptive diagnosis was reached on the basis of clinical signs at time of decompensation 18 hours postoperatively (hematochezia, abdominal distension, hypotension) and a previously identified thrombus during presurgical abdominal ultrasonography. Total hospital stay was reported in all dogs with the median being 2 days (range, 0.94 to 11 days). Total postoperative stay was reported in 99% of dogs (135/136) with the median stay being 28 hours (range, 1 to 138 hours). Splenic histopathology was performed in 99% of dogs (135/136) and revealed benign etiologies in 71.1% of spleens (96/136) and malignant etiologies in 28.9% (39/136; Table 1).

Table 1

Summary of splenic histopathologic diagnoses reported as the number and percentage of client-owned dogs with histopathology performed (n = 135) and total histopathologic diagnoses made (n = 214) after laparoscopic-assisted splenectomy between January 1, 2014, and July 31, 2020, at any of 8 participating facilities.

Diagnosis No. of dogs with diagnosis Percentage of dogs with diagnosis Percentage of total diagnoses made
Benign tumors 8 5.92 3.74
Myelolipoma 4 2.96 1.87
Hemangioma 3 2.22 1.4
Hamartoma 1 0.74 0.47
Malignant tumors 41 30.37 19.16
Hemangiosarcoma 19 14.07 8.88
Lymphoma 13 9.63 6.07
Sarcoma 7 5.19 3.27
Malignant neoplasm (subtype unknown) 1 0.74 0.47
Mesothelioma 1 0.74 0.47
Nontumorous findings 165a 122.21 77.1
Hyperplasia (nodular, lymphoid, other) 66 48.53 30.84
Hematoma 26 19.12 12.15
Extramedullary hematopoiesis 20 14.71 9.35
Congestion 10 7.35 4.67
Hemorrhage 7 5.15 3.27
Hemosiderosis 7 5.15 3.27
Infarct 4 2.9 1.87
Fibrosis 4 2.9 1.87
Fibrin 3 2.2 1.4
Splenitis (histiocytic, granulomatous) 2 1.47 0.93
Siderotic plaque(s) 2 1.47 0.93
Necrosis 2 1.47 0.93
Hematoidin (accumulation, within macrophages) 2 1.47 0.93
Thrombosis 2 1.47 0.93
Cystic mass, siderofibrosis, degeneration (hyaline vascular), myelopoiesis, proliferating fibroblasts, scattered adipose tissue, subendothelial proliferation, normal 1b 0.74a 0.47a

aSome dogs were diagnosed with multiple concurrent nontumorous findings.

nOne count per each diagnosis listed.

Statistical analysis

With the exception of age, the data distribution was not normal. Packed cell volume was a predictor of conversion with the potential as a diagnostic test with an OR of 1.1 and P = 0.0045 (Table 2). For each unit increase in PCV, there was 104% increased odds of not converting to open laparotomy to perform splenectomy. Receiver operating characteristic (ROC) curves were generated and cut points chosen based on the highest specificity and sensitivity values. A PCV cut point of 36 had a corresponding sensitivity and specificity of 85.7% and 74.4% with area under the curve of 0.85 and SE of 0.06. Six of the 8 conversions were captured with a cut point of 36. There were no other identified predictors.

Table 2

Results of univariate conditional logistic regression to determine risk factors for conversion from laparoscopic-assisted splenectomy to open laparotomy in 136 client-owned dogs undergoing laparoscopic-assisted splenectomy between January 1, 2014, and July 31, 2020, at any of 8 participating facilities.

Variable Median (range) no conversion Median (range) conversion OR 95% CI of the OR P value
Age (mo) 120 (1–135) 143 (124–192) 1.022 0.99–1.045 0.056
Body weight (kg) 23.65 (4–55) 17.7 (8.9–35) 0.975 0.915–1.034 0.414
Mass radius (cm) 1.75 (0.3–7.5) 3.1 (.55–3.5) 1.31 0.755–2.22 0.299
Volume (cm3) 22.07 (.113–1767) 124.78 (0.696–179.59) 1 0.997–1.003 0.853
PCV (%) 43 (13–62) 33 (19–41) 0.896 0.824–0.97) 0.0045*
Total solids (g/dL) 6.9 (0.2–9.5) 6.5 (5.6–9.2) 0.967 0.617–2.14 0.883
Surgery time (min) 47 (12–210) 47.5 (35–96) 0.994 0.967–1.014 0.612
Anesthesia time (min) 115 (60–360) 95 (70–270) 0.995 0.98–1.007 0.521
CBC performed† 114/124 1.074 0–5.9 0.632
Serum biochemical profile performed† 116/126 0.088 ∞–1.79 0.528

*Denotes statistically significant value (P < 0.05).

— = Not applicable.

†Data reported as proportion of animals.

Discussion

The results of the present study supported previous findings that LAS is an acceptable minimally invasive surgical technique for the treatment of splenic masses and diffuse splenic disease in the absence of free abdominal fluid in dogs. Hand-assisted laparoscopic surgery (HALS) approaches were developed to allow insertion of the surgeons’ hand into the abdomen to regain tactile feedback and improve intraperitoneal organ manipulation while maintaining a minimally invasive approach.15,16 This is especially beneficial in cases of splenomegaly, where total laparoscopic manipulation is challenging and frequently resulted in conversion to open laparotomy.17 HALS approaches for human splenectomy have since been shown to have reduced conversion rates relative to conventional laparoscopic splenectomy18,19 and is the preferred approach in cases of splenomegaly.19 Similar findings were supported in this study in dogs, where LAS was successfully performed to remove spleens with splenic masses up to 15 cm in diameter, or 55.2 cm3/kg by volume in dogs ranging from 4 to 55 kg. These data provide initial guidelines for case selection in dogs when surgeons are considering an LAS technique. Further prospective studies are recommended to provide surgeons with additional guidelines on splenic mass size for case selection for LAS; however, the present study showed positive outcomes with splenic masses with median radii of 1.85 cm (3.7 cm diameter) and volume per kilogram of 1.6 cm3/kg.

The median surgical time for LAS in the studied population, including additional procedures, was 47 minutes, (range, 12 to 210 minutes) which was shorter than previously reported in the preliminary LAS study (60 minutes).4 Due to the retrospective nature of this study, the surgical time reported included a wide range of concurrent procedures, which ranged from laparoscopic liver biopsy to intercostal thoracotomy. Even with the addition of a wide variety of concurrent procedures to the LAS technique, the median surgical time reported in this study is lower than most reported median surgical times for clinical cases of single-port total laparoscopic splenectomy of 75 minutes in one study9 and 115.4 minutes in another,3 as well as reports of open splenectomy of 51.5 minutes.3 The exception being a study by Khalaj et al8 which described a median surgical time for single-port and multi-port total laparoscopic splenectomy of 29.1 minutes and 42 minutes respectively. However, this study was limited to total splenectomy alone in the absence of concurrent procedures and was in research dogs with normal splenic architecture free of disease.8 When compared to the subpopulation of dogs in this study solely undergoing LAS, the median surgical time was 35 minutes, closer to which was reported by Khalaj et al in 2012.8 This reduced surgical time while maintaining a minimally invasive approach is a major advantage of the LAS technique.

The overall complication rate of 57.3% (78/136) reported in this study was higher than has been reported previously in both total laparoscopic and laparoscopic-assisted splenectomy studies.3,4 This rate included all perioperative complications, including those not directly related to surgery. Surgery associated complications represented only 17% (23/134) of the total number of complications documented in the study and all were non–life-threatening. In comparison, anesthesia-related complications represented 34% (46/134) of the total complications documented. There is a lack of agreement between researchers in the scientific literature on what constitutes a complication, which complications are reported, and reporting of overall complication rate versus rates of individual complications. In a retrospective study by Follette et al14 in 2018, it was reported that there was insufficient reporting and use of standardized criteria with regards to complications. In this report, complications were defined according to the VCOG-CTCAE v2 guidelines to identify any complication during the hospitalization period.14 In addition, this study did not limit complications with regard to severity, type or timeframe within hospitalization (for example, during surgery alone), which can explain why the complication rate appears to be high relative to other studies. Despite the high rate, all complications (134/134 [100%]) were graded as a 2 or lower, with zero grade 3 and 4 complications. Though the definition for a grade 2 complication varies between complication type in the VCOG-CTCAE v2 guidelines, grade 2 complications are typically those that are of minimal to moderately severity, and not a threat to life. In previous total laparoscopic splenectomy studies, complications, when reported, were frequently associated with mass rupture during intracorporal manipulation. This operative maneuver is not performed with the LAS technique as the splenectomy is essentially performed extracorporeally, resulting in a minimal major complication rate.

All but 1 dog survived to hospital discharge following LAS. The deceased dog was presumed to have died of a portal vein thrombus that was found preoperatively with abdominal ultrasonography. The underlying cause was not identified, and a postmortem examination was not obtained. In a retrospective study detailing risk factors associated with death in dogs undergoing splenectomy, portal vein thrombosis was diagnosed or suspected in 22% of the patients that failed to survive to discharge and was second only to uncontrolled hemorrhage (24.4%).1

Median hospitalization time and postoperative hospital stay were short and attributed to the minimally invasive LAS approach. One dog remained hospitalized for 11 days postoperatively; the dog was initially presented following a dog fight and was thrombocytopenic, with continued oral and gastrointestinal hemorrhage. Splenectomy was performed to control the thrombocytopenia; however, hospital stay was prolonged secondary to treatment of its thrombocytopenia and not due to surgical complications.

Previous contraindications to LAS include the presence of hemorrhage, large splenic masses, and splenic torsion.4 With appropriate case selection, the LAS technique was sufficient for total splenectomy in a wide population of dogs, representing a large variation in weights, ages, and breeds. For 3 of the 8 dogs that required conversion to open laparotomy, the conversion was needed because of the presence of hemoabdomen on entry to the abdomen which was not reported at the time of diagnostic imaging. This could suggest that to optimize case selection and resource allocation that diagnostic imaging, preferably abdominal ultrasonography, or an abdominal focused assessment with sonography for trauma (FAST), be performed close or immediately prior to the time of surgery. Additionally, statistical analysis revealed that PCV was significantly and inversely correlated with increased risk of conversion. Using a PCV cut point of 36 had a sensitivity of 85.7% and specificity of 74.4% with regards to conversion to open laparotomy, and in this study captured 6 of the 8 conversions. Evaluation of PCV prior to LAS may improve case selection for LAS.

Similar to other studies involving total laparoscopic and laparoscopic-assisted splenectomy in dogs, the majority of histopathologic diagnoses in this study population were benign.9,11 Hemangiosarcoma accounted for only 14% of histopathologic diagnoses, which is much lower than what has been previously reported in retrospective studies reporting reasons for splenectomy in dogs.1,20 This could be related to the propensity of patients with hemangiosarcoma to present with a hemoabdomen, which, at this time, is considered a contraindication for total laparoscopic and laparoscopic-assisted splenectomy.

Limitations of this study include its multi-institutional and retrospective nature. The LAS procedure was performed by numerous surgeons with varying experience with minimally invasive surgery. The retrospective nature of this study prevented standardization in diagnostic imaging, operative technique, and anesthesia protocol.

In conclusion, LAS is an acceptable and effective minimally invasive surgical technique associated a minimal conversion rate and excellent short-term outcomes in dogs, and PCV was a predictor of conversion. The LAS technique reported in this study should be considered by the minimally invasive veterinary surgeon for total splenectomy in dogs with moderate sized splenic masses, without evidence of hemorrhage, and a PCV cut point of 36.

Acknowledgments

No third-party funding or support was received in connection with this study or the writing or publication of the manuscript. The authors declare no conflict of interest related to this report.

Author contributions: Marissa E. S. McGaffey was responsible for acquisition, analysis, and interpretation of data, drafting and revision of the manuscript, and approval of final manuscript; Ameet Singh was responsible for study conception and design, senior case clinician, data acquisition and interpretation, and revision and approval of final manuscript; Nicole J. Buote was senior case clinician, and was responsible for data acquisition, and revision and approval of final manuscript; Philipp D. Mayhew was senior case clinician, and was responsible for data acquisition, and revision and approval of final manuscript; Nicole Rupnik was responsible for data acquisition and approval of final manuscript; Federico Massari was senior case clinician, and was responsible for data acquisition, and revision and approval of final manuscript; J. Brad Case was senior case clinician, and was responsible for data acquisition, and revision and approval of final manuscript; Boel A. Fransson was senior case clinician, and was responsible for data acquisition, and revision and approval of final manuscript; Michelle L. Oblak was senior case clinician, and was responsible for data acquisition, and revision and approval of final manuscript; Brigitte A. Brisson was senior case clinician, and was responsible for data acquisition, and revision and approval of final manuscript; Jacqueline E. Scott was senior case clinician, and was responsible for data acquisition, and revision and approval of final manuscript; Victoria A. Donovan was responsible for data acquisition, and revision and approval of final manuscript; Ryan Appleby was responsible for study conception, and revision and approval of final manuscript.

References

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    Wendelburg KM, O’Toole TE, McCobb E, Price LL, Lyons JA, Berg J. Risk factors for perioperative death in dogs undergoing splenectomy for splenic masses: 539 cases (2001–2012). J Am Vet Med Assoc. 2014;245(12):13821390. doi:10.2460/javma.245.12.1382

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    Stedile R, Beck CAC, Schiochet F, et al. Laparoscopic versus open splenectomy in dogs. Pesqui Vet Bras. 2009;29:653660. doi:10.1590/S0100-736X2009000800009

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  • 4.

    Wright T, Singh A, Mayhew PD, et al. Laparoscopic-assisted splenectomy in dogs: 18 cases (2012–2014). J Am Vet Med Assoc. 2016;248(8):916922. doi:10.2460/javma.248.8.916

    • PubMed
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  • 5.

    Tobias KM. Abdominal procedures. In: Tobias KM, ed. Manual of Small Animal Soft Tissue Surgery. 1st ed. John Wiley & Sons; 2009:103108.

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    • Export Citation
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    Fossum TW. Surgery of the hemolymphatic system. In: Fossum TW, ed. Small Animal Surgery. 4th ed. Mosby; 2018:692705.

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    Bleedorn JA, Dykeman JL, Hardie RJ. Minimally invasive surgery in veterinary practice: a 2010 survey of diplomates and residents of the American College of Veterinary Surgeons. Vet Surg. 2013;42(6):635642. doi:0.1111/j.1532-950X.2013.12025.x

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    Khalaj A, Bakhtiari J, Niasari-Naslaji A. Comparison between single and three portal laparoscopic splenectomy in dogs. BMC Vet Res. 2012;8):161. doi:10.1186/1746-6148-8-161

    • PubMed
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    Mayhew PD, Sutton JS, Singh A, et al. Complications and short-term outcomes associated with single-port laparoscopic splenectomy in dogs. Vet Surg. 2018;47(S1):O67O74. doi:10.1111/vsu.12752

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    Maurin MP, Mullins RA, Singh A, Mayhew PD. A systematic review of complications related to laparoscopic and laparoscopic-assisted procedures in dogs. Vet Surg. 2020;49(suppl 1):O5O14. doi:10.1111/vsu.13419

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    Shaver SL, Mayhew PD, Steffey MA, Hunt GB, Mayhew KN, Culp WTN. Short-term outcome of multiple port laparoscopic splenectomy in 10 dogs. Vet Surg. 2015;44(suppl 1):7175. doi:10.1111/j.1532-950X.2014.12312.x

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  • 12.

    LeBlanc AK, Atherton M, Bentley RT, et al. Veterinary Cooperative Oncology Group—Common Terminology Criteria for Adverse Events (VCOG-CTCAE v2) following investigational therapy in dogs and cats. Vet Comp Oncol. 2021;19(2):311352. doi:10.1111/vco.12677

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    Case JB, Ellison G. Single incision laparoscopic-assisted intestinal surgery (SILAIS) in 7 dogs and 1 cat. Vet Surg. 2013;42(5):629634. doi:10.1111/j.1532-950X.2013.12017.x

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  • 14.

    Follette CM, Giuffrida MA, Balsa IM, et al. A systematic review of criteria used to report complications in soft tissue and oncologic surgical clinical research studies in dogs and cats. Vet Surg. 2020;49(1):6169. doi:10.1111/vsu.13279

    • PubMed
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    • Export Citation
  • 15.

    Targarona EM, Balague C, Cerdán G, et al. Hand-assisted laparoscopic splenectomy (HALS) in cases of splenomegaly: a comparison analysis with conventional laparoscopic splenectomy. Surg Endosc. 2002;16(3):426430. doi:10.1007/s00464-001-8104-z

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Kaban GK, Czerniach DR, Cohen R, et al. Hand-assisted laparoscopic splenectomy in the setting of splenomegaly. Surg Endosc. 2004;18(9):13401343. doi:10.1007/s00464-003-9175-9

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17.

    Bemelman WA, de Wit LT, Busch OR, Gouma DJ. Hand-assisted laparoscopic splenectomy. Surg Endosc. 2000;14(11):997998. doi:10.1007/s004640080121

  • 18.

    Qian D, He Z, Hua J, Gong J, Lin S, Song Z. Hand-assisted versus conventional laparoscopic splenectomy: a systematic review and meta-analysis. ANZ J Surg. 2014;84(12):915920. doi:10.1111/ans.12597

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19.

    Sun X, Liu Z, Huang Y. Hand-assisted laparoscopic splenectomy advantages over complete laparoscopic splenectomy for splenomegaly. Surg Laparosc Endosc Percutan Tech. 2019;29(2):109112. doi:10.1097/SLE.0000000000000640

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20.

    Leyva FJ, Loughin CA, Dewey CW, Marino DJ, Akerman M, Lesser ML. Histopathologic characteristics of biopsies from dogs undergoing surgery with concurrent gross splenic and hepatic masses: 125 cases (2012–2016). BMC Res Notes. 2018;11(1):122. doi:10.1186/s13104-018-3220-1

    • PubMed
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    • Export Citation
  • Figure 1

    Frequency distribution of the types of complications occurring between anesthetic induction and hospital discharge or death for 136 client-owned dogs undergoing laparoscopic-assisted splenectomy between January 1, 2014, and July 31, 2020, at any of 8 participating facilities grouped by grade (grade 1, 2, or not reported).

  • 1.

    Wendelburg KM, O’Toole TE, McCobb E, Price LL, Lyons JA, Berg J. Risk factors for perioperative death in dogs undergoing splenectomy for splenic masses: 539 cases (2001–2012). J Am Vet Med Assoc. 2014;245(12):13821390. doi:10.2460/javma.245.12.1382

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2.

    Collard F, Nadeau ME, Carmel EN. Laparoscopic splenectomy for treatment of splenic hemangiosarcoma in a dog. Vet Surg. 2010;39(7):870872. doi:10.1111/j.1532-950X.2010.00721.x

    • Search Google Scholar
    • Export Citation
  • 3.

    Stedile R, Beck CAC, Schiochet F, et al. Laparoscopic versus open splenectomy in dogs. Pesqui Vet Bras. 2009;29:653660. doi:10.1590/S0100-736X2009000800009

    • Search Google Scholar
    • Export Citation
  • 4.

    Wright T, Singh A, Mayhew PD, et al. Laparoscopic-assisted splenectomy in dogs: 18 cases (2012–2014). J Am Vet Med Assoc. 2016;248(8):916922. doi:10.2460/javma.248.8.916

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Tobias KM. Abdominal procedures. In: Tobias KM, ed. Manual of Small Animal Soft Tissue Surgery. 1st ed. John Wiley & Sons; 2009:103108.

    • Search Google Scholar
    • Export Citation
  • 6.

    Fossum TW. Surgery of the hemolymphatic system. In: Fossum TW, ed. Small Animal Surgery. 4th ed. Mosby; 2018:692705.

  • 7.

    Bleedorn JA, Dykeman JL, Hardie RJ. Minimally invasive surgery in veterinary practice: a 2010 survey of diplomates and residents of the American College of Veterinary Surgeons. Vet Surg. 2013;42(6):635642. doi:0.1111/j.1532-950X.2013.12025.x

    • Search Google Scholar
    • Export Citation
  • 8.

    Khalaj A, Bakhtiari J, Niasari-Naslaji A. Comparison between single and three portal laparoscopic splenectomy in dogs. BMC Vet Res. 2012;8):161. doi:10.1186/1746-6148-8-161

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9.

    Mayhew PD, Sutton JS, Singh A, et al. Complications and short-term outcomes associated with single-port laparoscopic splenectomy in dogs. Vet Surg. 2018;47(S1):O67O74. doi:10.1111/vsu.12752

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10.

    Maurin MP, Mullins RA, Singh A, Mayhew PD. A systematic review of complications related to laparoscopic and laparoscopic-assisted procedures in dogs. Vet Surg. 2020;49(suppl 1):O5O14. doi:10.1111/vsu.13419

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11.

    Shaver SL, Mayhew PD, Steffey MA, Hunt GB, Mayhew KN, Culp WTN. Short-term outcome of multiple port laparoscopic splenectomy in 10 dogs. Vet Surg. 2015;44(suppl 1):7175. doi:10.1111/j.1532-950X.2014.12312.x

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 12.

    LeBlanc AK, Atherton M, Bentley RT, et al. Veterinary Cooperative Oncology Group—Common Terminology Criteria for Adverse Events (VCOG-CTCAE v2) following investigational therapy in dogs and cats. Vet Comp Oncol. 2021;19(2):311352. doi:10.1111/vco.12677

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 13.

    Case JB, Ellison G. Single incision laparoscopic-assisted intestinal surgery (SILAIS) in 7 dogs and 1 cat. Vet Surg. 2013;42(5):629634. doi:10.1111/j.1532-950X.2013.12017.x

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 14.

    Follette CM, Giuffrida MA, Balsa IM, et al. A systematic review of criteria used to report complications in soft tissue and oncologic surgical clinical research studies in dogs and cats. Vet Surg. 2020;49(1):6169. doi:10.1111/vsu.13279

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 15.

    Targarona EM, Balague C, Cerdán G, et al. Hand-assisted laparoscopic splenectomy (HALS) in cases of splenomegaly: a comparison analysis with conventional laparoscopic splenectomy. Surg Endosc. 2002;16(3):426430. doi:10.1007/s00464-001-8104-z

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Kaban GK, Czerniach DR, Cohen R, et al. Hand-assisted laparoscopic splenectomy in the setting of splenomegaly. Surg Endosc. 2004;18(9):13401343. doi:10.1007/s00464-003-9175-9

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17.

    Bemelman WA, de Wit LT, Busch OR, Gouma DJ. Hand-assisted laparoscopic splenectomy. Surg Endosc. 2000;14(11):997998. doi:10.1007/s004640080121

  • 18.

    Qian D, He Z, Hua J, Gong J, Lin S, Song Z. Hand-assisted versus conventional laparoscopic splenectomy: a systematic review and meta-analysis. ANZ J Surg. 2014;84(12):915920. doi:10.1111/ans.12597

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19.

    Sun X, Liu Z, Huang Y. Hand-assisted laparoscopic splenectomy advantages over complete laparoscopic splenectomy for splenomegaly. Surg Laparosc Endosc Percutan Tech. 2019;29(2):109112. doi:10.1097/SLE.0000000000000640

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20.

    Leyva FJ, Loughin CA, Dewey CW, Marino DJ, Akerman M, Lesser ML. Histopathologic characteristics of biopsies from dogs undergoing surgery with concurrent gross splenic and hepatic masses: 125 cases (2012–2016). BMC Res Notes. 2018;11(1):122. doi:10.1186/s13104-018-3220-1

    • PubMed
    • Search Google Scholar
    • Export Citation

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