It’s comforting to know there is "Hope".
Ilona and Bill
- Signalment: 11-year-old female spayed beagle (12 kg)
- Presenting complaint: Vomiting, diarrhea, lethargy, inappetence, stranguria/tenesmus, and incontinence
- Pertinent history: Diagnosed 2 months previously with transitional cell carcinoma; Progressive disease following 3 doses of chemotherapy and NSAIDs
- Medications: Piroxicam, Misoprostal
- Physical examination findings: Quiet, alert, and responsive; Heart rate 140 bpm; body condition score 5/9; Multiple soft moveable subcutaneous masses; Moderate bilateral hindlimb muscle atrophy; Very large caudal abdominal structure consistent with distended urinary bladder; lumbar lymph nodes not palpable on rectal examination; Drops of urine dripping from vulva
- Complete blood count: Mild stress leukogram
- Serum chemistry profile: Cr 7.6, BUN >150
- Abdominal radiography: Distended urinary bladder; Hepatomegaly
- Thoracic radiography: Unremarkable
- Abdominal ultrasonography: Soft-tissue mass located within firm urinary bladder body and trigone and extending into/from proximal urethra; Intra-pelvic urethra not visualized; Lumbar lymph nodes within normal limits; Bilateral severe hydroureter and hydronephrosis with left renal pelvis 2.6cm and right renal pelvis 2cm (Figure 1); slightly enlarged hyperechoic liver; Remaining structures unremarkable
- Urinalysis / Urine Culture: Negative
This patient was determined to have a complete or near complete urethral obstruction and bilateral ureteral obstructions secondary to progressive urothelial carcinoma. An urethral catheter was placed in the emergency room and 400 ml of hematuria was removed from the urinary bladder. The elevated heart rate came down following bladder drainage. Discussion with the owner included surgery (ureteral stents or reimplantation, cystostomy tube), radiation therapy (palliative or full course) with periodic urinary catheterization (BID-TID) until urethral patency, percutaneous ureteral stenting and urethral stenting. In addition, tumor extension into the trigone as well as urethral involvement made complete surgical resection an unlikely option unless a radical surgery was performed. Total cystectomy with subcutaneous ureterovesicular bypass (SUB) device placement was discussed. Medical management (chemotherapy) was discussed but acute response permitting urination was unlikely. The owner chose total cystectomy as a rapid, effective, procedure shown to provide immediate relief of stranguria and possibly tenesmus by immediate restoration urine flow with the potential for microscopic disease only remaining.
The patient was placed under general anesthesia and positioned in dorsal. A midline ventral abdominal incision was made. Locking-loop nephrostomy catheters are placed in each kidney using surgical and fluoroscopic guidance (Figure 2). The urinary bladder was removed en bloc including total cystectomy, bilateral partial ureterectomies, and urethrectomy down to the vagina. A specialized urethral catheter is placed into the vagina and the three separate catheters are attached to the 3-way shunting port placed in the subcutaneous space (Figure 3). By removing the entire lower urinary tract en bloc we improve our chances of achieving complete tumor excision. Iodinated contrast agent is injected into the 3-way shunting port under fluoroscopy to ensure patency of all catheters and decompression of the previously distended renal pelvises. The abdomen is flushed and closed routinely.
This patient was discharged from the hospital 2 days later with immediate resolution of the urinary obstruction. Prior to discharge, repeat bloodwork demonstrated improved creatinine (between 2.9 and 4.9) and resolution of the hydronephrosis (Figure 4). As the urinary bladder was removed, the patient continued to be incontinent but the stranguria and tenesmus had resolved. Discharge medications included a 2-week tapering dose of enrofloxacin pending the urine culture results. A recheck examination was scheduled two weeks later for suture removal and discussion with an oncologist to discuss further treatment options. Follow-up evaluations with the interventional radiology service are scheduled approximately every 2 months to monitor for urinary tract infections/pyelonephritis (one of the most common complications in total cystectomy/incontinent dogs) and recurrent obstructions (diagnosed via ultrasound). SUB flushes are performed in the awake patient at each visit to ensure patency and check urine cultures.
While the majority of human TCCs are superficial in origin responding well to local therapies such as intravesicular chemotherapy or laser ablation, the more uncommon “muscle-invasive” TCC cases have little response to medical therapy and are often treated with radical cystectomies. Unfortunately for veterinarians, approximately 95+% of canine TCCs are classified as the “muscle-invasive” type and have limited continued clinical response to chemotherapy and radiation therapy. Even initial biological responses are routinely non-durable and subsequent tumor growth and spread ultimately leads to patient death or euthanasia within approximately a year or so following diagnosis.1-2 Contrary to theoretical advantages, radical surgical resections have not been demonstrated to consistently provide improved chemotherapy responsiveness or prolonged survival times. In addition, reported complications associated with rerouting procedures have dissuaded many from pursuing these aggressive alternatives.3 We have previously reported on the rapid, safe, and successful use of a novel subcutaneous ureteral bypass device in dogs and cats with nonmalignant ureteral obstructions. Radical cystectomies with subcutaneous ureterovesicular bypass (SUB) placement can permit more aggressive, wider tumor resections without the prior concerns of sufficient working lengths of remaining urinary tract structures. In addition, the procedures can be rapid, safe, and effective in re-establishing urinary tract patency compared to the more involved rerouting surgeries historically performed. This procedure is currently under evaluation and has been reported only in abstract form.4 The preliminary results in 5 dogs have demonstrated improved ability to achieve wide surgical margins in female (compared to male) dogs with few surgical complications but chronic infections remain a challenge when patients will be receiving subsequent chemotherapeutics.
1 Norris AM, Laing EJ, Valli VEO, et al. Canine bladder and urethral tumors: a retrospective study of 115 cases (1980–1985). J Vet Intern Med 1992;16:145–153.
2 Knapp DW, Glickman NW, DeNicola DB, et al. Naturally occurring canine transitional cell carcinoma of the urinary bladder. A relevant model of human invasive bladder cancer. Urol Oncol 2000;5:47–59.
3 Stone EA, Withrow SJ, Page RL, et al. Ureterocolonic anastomosis in ten dogs with transitional cell carcinoma. Vet Surg 1988;17:147–153.
4 Weisse C, Berent A. Radical cystectomy and bilateral subcutaneous ureterovesicular bypass placement for advanced urinary bladder cancer in dogs. ACVIM 2014.
Figure 1: Ultrasonography (top) and positive contrast urethrocystogram (bottom) images of patient with large bladder and proximal urethral tumor consistent with transitional cell carcinoma.
Figure 2: Serial images demonstrating placement of the subcutaneous ureterovesicular bypass (SUB) device. A. Placement of locking loop nephrostomy catheter. B. the SUB device. C. Contrast pyelogram showing the nephrostomy catheter loop (black arrow) within the contrast filled renal pelvis (white arrow). D. The SUB device shunting port sutured subcutaneously. This port can be sampled and flushed as necessary.
Figure 3: Post-operative lateral (left) and ventrodorsal (right) radiographs demonstrating placement of the SUB device in both kidneys with a urethral catheter placed in the vagina following removal of the distal ureters, urinary bladder, and urethra.
Figure 4: Serial ultrasonographic images demonstrating bilateral hydronephrosis prior to (left) and following (right) SUB placement. Complete resolution of the renal pelvic dilation is demonstrated and improved renal function confirmed with bloodwork.
History: A 7-year-old female spayed Golden Retriever presented to her rDVM for evaluation of a left thoracic limb (LTL) lameness of two months duration. Lameness was accompanied by anorexia and lethargy as well as forequarter muscle tremors. Physical exam confirmed LTL lameness. Radiographs of the shoulder and elbow did not reveal any definitive lesions. The problem was managed conservatively with controlled activity and carprofen, 75mg PO BID. The lameness progressed and the patient was referred to a neurologist for further evaluation. On presentation to the referral clinic it was determined that the patient had developed coughing and gagging of 1 week duration when eating. There was no history of tick or toxin exposure or of any trauma or travel history. The patient was toe touching lame on the LTL and exhibited pain on flexion and extension of the shoulder. The heart sounds were muffled. A neurologic exam revealed normal conscious proprioception but this was difficult to assess on the LTL. There was a decreased withdrawal on the LTL but the remainder of the exam was unremarkable. Initial staging tests were done:
Bloodwork consisting of a CBC and chemistry were within normal limits apart from a thrombocytosis (663,000) associated with a prior splenectomy. An abdominal ultrasound was unremarkable, but thoracic radiographs revealed a cranial mediastinal mass effect with secondary pleural effusion and a globoid appearing cardiac silhouette (suspect pericardial effusion) (Images 1 and 2). An ultrasound of the cranial mediastinum revealed an extensive infiltrative cystic mediastinal mass and confirmed the presence of pericardial effusion. A fine needle aspirate of the mass was obtained and submitted for analysis. A highly cellular sample was reported consisting of round to irregular shaped cells of marked to moderate anisocytosis and anisokaryosis. There was abundant finely granular blue-grey cytoplasm with clear vacuoles. The nuclei were round to oval, some with flattened or indented sides. Nucleoli were prominent and had an immature chromatin pattern (image 3). The findings were reported as a highly probable histiocytic sarcoma (HS). Immunocytochemistry was done with a panel of markers and the cells were CD1c+, CD79- and CD3- (image 4), confirming the diagnosis of HS. An echocardiogram revealed severe pericardial effusion with right atrial compression (cardiac tamponade). The left atrium and right and left ventricles were small and volume under-loaded secondary to the pericardial effusion. No mass was observed around the aorta or in the right atrium/auricle. Pericardiocentesis recovered 400mls of a chylous fluid with moderate secondary suppurative inflammation on fluid analysis. No infectious agents or evidence of neoplasia was observed and the effusion was deemed most likely to be secondary to lymphatic obstruction by the mediastinal mass.
Two days after presenting for neurology workup, the patient was referred to the oncology service to discuss prognosis and treatment options. The patient presented laterally recumbent with marked regurgitation and recurrent cardiac tamponade. Treatment options discussed included chemotherapy with CCNU, surgery and radiation therapy but a guarded to poor prognosis was given. The owners elected to proceed with a combination of definitive radiation therapy and CCNU. A CT scan was obtained which showed a non-uniform contrast enhancing mass on the caudal medial aspect of the proximal humerus as well as enlarged axillary and accessory axillary lymph nodes measuring 2.5×2.3 and 1.1 cm in diameter respectively. The cranial mediastinal mass measured 8.1×5.6cm at the largest cross section and extended from C5 cranially to the level of the aortic arch caudally (image 5). The plan was to administer 16×3 Gy fractions to a total of 48Gy via parallel, opposed treatment portals. Prednisone was started at 20mg PO SID. By the end of the first week of treatment the patient was ambulatory again and by treatment 11 a vast clinical improvement was observed with resolution of the regurgitation as well. Further improvement occurred throughout the course of therapy and by 1week post radiation only a very subtle LTL lameness was noted. Follow up imaging showed marked resolution of the previously noted mediastinal and proximal humeral mass lesions (Image 6). The patient received 8 doses of CCNU (70mg/m2) at 3week intervals over the next 6 months.
At that time the pleural effusion recurred. Restaging with thoracic radiographs and an abdominal ultrasound showed no evidence of progressive disease (Images 7 and 8). A therapeutic thoracocentesis was done and prednisone was restarted with marked improvement clinically. Two months after this the patient presented in respiratory distress with recurrent effusion and was also found to be in renal failure. Euthanasia was elected at that time, 10 months following presentation to the referral clinic. Necropsy examination showed diffuse, moderate, chronic membranoproliferative glomerulnephritis with moderate periglomerular and interstitial fibrosis; multifocal, moderate acute, neutrophilic hepatitis and vacuolar hepatopathy; and multifocal, severe chronic degeneration and necrosis within the myocardium. No evidence of histiocytic sarcoma was found in either the mediastinum or the previously affected limb.
Histiocytic neoplasia is an increasingly common and complex group of malignancies affecting the canine species. Canine histiocytic neoplasia can present as benign, spontaneously regressing tumors (cutaneous histiocytoma) (1) or may occur as either localized or disseminated malignancies (2) and even as a primary leukemia. (3) Localized histiocytic sarcoma (LHS) develops at a single site, usually arising in the subcutis and involving muscle or joint although other primary locations, including internal organs such as lung, spleen and tongue have been observed. (2,4) Disseminated histiocytic sarcoma (DHS) is an aggressive disease characterized by multiple neoplastic lesions within multiple organ systems. Primary sites generally include spleen, lung and bone marrow with secondary lesions in liver, lymph node and other organs. (2) To date, a great deal of effort has gone into classification of histiocytic neoplasia and in differentiating histiocytic malignancies from reactive disorders. This effort has largely centered on the use of monoclonal antibody panels to determine the cells’ phenotypic expression in tandem with a morphologic histopathology assessment. A recent study characterized LHS and DHS as having identical morphologic and phenotypic features consistent with cells of a myeloid dendritic antigen presenting cell origin. (2) Additional studies have used immunohistochemistry to illustrate that histiocytic malignancies also arise from macrophage (hemophagocytic HS) (5) and langerhans cell lineages [(solitary and multiple histiocytoma) (6) and (langerhans cell histiocytosis) (7)] respectively.
However, very little information is available on the treatment and outcome of patients with HS. One study evaluating the use of CCNU alone to treat HS showed an overall response rate of 46% and reported an overall median survival time of 106 days. (8) A second study reported on the use of various combinations of surgery, chemotherapy and radiation therapy to treat histiocytic-like sarcomas not confirmed by immunohistochemical markers. (9) The median survival time for all dogs in that study was 123 days, but chemotherapy and radiation therapy were significantly associated with improved survival. The overall metastatic rate was reported as 70%, but may have been higher since post-mortem evaluation was not performed on all dogs. Given the high metastatic potential of HS, there is rationale for adjuvant systemic chemotherapy in conjunction with either surgery and/or radiation therapy. In one report describing wide surgical excision or amputation, a cure was achieved in 5/13 dogs with large HS masses on extremities, while the remaining eight dogs were lost to follow-up. (2) However, another study of 18 dogs with synovial HS, reported an overall median survival time of 3.6 months and a median survival time for dogs undergoing amputation (with or without chemotherapy) of 6 months with a 91% metastatic rate. (4) This discrepancy in survival may be a reflection of early versus late detection and initiation of treatment prior to the onset of metastasis. It remains unclear whether DHS arises as a primary multicentric malignancy or as the terminal stage of LHS with rapid metastasis. However, early recognition of tumors in easily accessible areas such as the subcutis can facilitate timely surgical excision or radiotherapy and may decrease the chance of systemic spread. This is supported by the findings of a more recent study which reported that peri-articular HS (PAHS) had a more favorable outcome than non-PAHS with median survival times of 391 and 128 days respectively.(10) This same study also reported that dogs with PAHS without metastatic disease at diagnosis had significantly longer survivals than those with metastatic lesions (980 vs 253 days) respectively. In addition, it has been reported that long-term survival (median survival of 568 days) is possible in dogs with LHS treated with aggressive local therapy (surgery and/or radiation therapy) with adjuvant chemotherapy. (11)
Further therapeutic discussion for HS in the veterinary literature is limited. An interesting avenue of enquiry is in the use of bisphosphonates to treat HS. Clodronate, a bisphosphonate has been shown to have macrophage-depleting properties in both the auto-immune (12) and tumor settings. (13) When clodronate is incorporated into liposomes, the drug is preferentially phagocytosed by macrophages and some dentritic cells, leading to rapid apoptosis of cells that phagocytose the liposomes. (14 15) The drug has been used safely in dogs and has been found to induce rapid killing of canine splenic macrophages and dendritic cells in vitro. (18) The use of bisphosphonates together with chemotherapy has been shown to enhance cell killing of malignant histiocytosis cells in vitro. (16) The combination of clodronate with vincristine and zoledronate combined with doxorubicin significantly increased cell killing. Based on these findings, we can conclude that certain bisphosphonate drugs may increase the overall effectiveness of chemotherapy for HS in dogs.
Currently, the veterinary literature reports on 18 patients treated with radiation therapy as a component of therapy for histiocytic-like sarcomas. (9) Sixteen dogs received a coarse fractionation protocol (either 3 x 8 Gy or 5 x 6 Gy) and two dogs received more definitive irradiation of 12 x 4 Gy and 14 x 3.5 Gy respectively. In those dogs evaluated for response to radiation, response was rapid, with complete (68%) and partial (26%) responses reported by the 3rd week post therapy. The median time to failure in dogs receiving radiation was 120 days, but failure was defined as either local or distant relapse and the direct effect of these radiation therapy protocols on local lesion control could not be determined. However, no differences were detected in survival between dogs receiving definitive versus coarse fractionation. To date, there is no published radiation protocol recommended to treat histiocytic sarcoma. Results from the authors anecdotal experience, suggest that HS cells are highly radiosensitive to standard fractions of 3 Gy delivered to a total dose of 48 Gy. The outcome in this case report suggests that a complete response of the primary tumor is possible even with regional metastatic lymph node disease and that greater consideration should be given to aggressive treatment of these patients.
- Yang TJ. Spontaneously regressive canine cutaneous histiocytoma: a counterpart of human regressing atypical histiocytosis? Anticancer Res 1987;7:811-812.
- Affolter VK, Moore PF. Localized and disseminated histiocytic sarcoma of dendritic cell origin in dogs. Vet Pathol 2002;39:74-83.
- Allison RW, Brunker JD, Breshears MA, et al. Dentric cell leukemia in a Golden Retriever. Veterinary Clinical Pathology 2008;37:190-197.
- Craig LE, Julian ME, Ferracone JD. The diagnosis and prognosis of synovial tumors in dogs: 35 cases. Vet Pathol 2002;39:66-73.
- Moore PF, Affolter VK, Vernau W. Canine hemophagocytic histiocytic sarcoma: A proliferative disorder of CD11d+ macrophages. Veterinary Pathology 2006;43:632-645.
- Moore PF, Schrenzel MD, Affolter VK, et al. Canine cutaneous histiocytoma is an epidermotropic Langerhans cell histiocytosis that expresses CD1 and specific beta 2-integrin molecules. Am J Pathol 1996;148:1699-1708.
- Nagata M, Hirata M, Ishida T, et al. Progressive Langerhans’ cell histiocytosis in a puppy. Veterinary Dermatology 2000;11:241-246.
- Skorupski KA, Clifford CA, Paoloni MC, et al. CCNU for the treatment of dogs with histiocytic sarcoma. Journal of Veterinary Internal Medicine 2007;21:121-126.
- Fidel J, Schiller I, Hauser B, et al. Histiocytic sarcomas in flat-coated retrievers: a summary of 37 cases (November 1998-March 2005). Veterinary and Comparative Oncology 2006;4:63-74.
- Klahn SL, Kitchell BE, Dervisis NG. Evaluation and comparison of outcomes in dogs with periarticular and nonperiarticular histiocytic sarcoma. Journal of the veterinary medical association 2011; 239:90-96.
- Skorupski KA, Rodriguez CO, Krick EL ,et al. Long-term survival in dogs with localized histiocytic sarcoma treated with CCNU as an adjuvant to local therapy. Veterinary and comarative oncology 2009; 7:139-144.
- Mathes M, Jordan M, Dow S. Evaluation of liposomal clodronate in experimental spontaneous autoimmune hemolytic anemia in dogs. Experimental Hematology 2006;34:1393-1402.
- Zeisberger SM, Odermatt B, Marty C, et al. Clodronate-liposome-mediated depletion of tumor-associated macrophages: a new and highly effective antiangiogenic therapy approach. British Journal of Cancer 2006;95:272-281.
- Van Rooijen N. The liposome-mediated macrophage “suicide” technique. Journal of Immunological Methods 1989;124:1-6.
- Naito M, Nagai H, Kawano S, et al. Liposome-encapsulated dichloromethylene diphosphonate induces macrophage apoptosis in vivo and in vitro. Journal of Leukocyte Biology 1996;60:337-344.
- Hafeman SD, Varland D, and Dow SW. Bisphosphonates Significantly Increase the Activity of Doxorubicin or Vincristine Against Canine Malignant Histiocytosis Cells. Veterinary and comarative oncology 2012; 10:44-56.
Image 2. Pre-radiation (ventro-dorsal projection). Note the thickened cranial mediastinum, globoid cardiac silhouette and pleural effusion.
Image 5. Pre-radiation. Note the very large space occupying mass in the cranial mediastinum.
Image 6. Post-radiation. The previously noted mass is no longer visible in this corresponding view of the cranial mediastinum.
Image 7. Post-radiation
Image 8. Post-radiation
The diagnosis and treatment of cancers in animals and people has recently been revolutionized with some remarkable technology and advancements. These include PET scans for the diagnosis and monitoring of response to treatment of tumors; targeted chemotherapy for the individualized treatment of cancer patients; and stereotactic and intensity-modulated radiation therapy for more targeted and safer irradiation of certain cancers. But what about surgery? Surgical oncologists have a better understanding of the cancers we treated through collaborative research efforts coordinated by the Veterinary Society of Surgical Oncology and other institutions, but our field has not grown and advanced at the same rate as diagnostics and radiation … until now.
Three-dimensional (3D) printing was initially developed in the 1980s, but it has not been until recently that this technology has been adopted in the medical field, especially in surgical oncology. 3D printing is a manufacturing process in which materials are fused together in layers to produce a three-dimensional object. The medical applications of 3D printing are wide ranging. Initially, 3D printing of bones or organs allowed improved surgical planning. More recently, we have been using 3D printing technology to print titanium implants that are custom designed and manufactured for individual patients. This technology has not only benefitted individual patients, but also may provide proof of concept that will revolutionize treatment of certain cancers and also provide translational research and practical opportunities as part of the “One Medicine, One Health” initiative.
Bailey, an 8-year-old, female spayed Labrador Retriever, was diagnosed with a tarsal osteosarcoma (OSA) (Figure 1).
Figure 1. Dorsoplantar radiograph of Bailey’s tarsal osteosarcoma showing marked lytic destruction of the tarsal and metatarsal bones.
The owners declined amputation and were interested in limb-sparing options. The tumor was too advanced for stereotactic radiotherapy and the tarsus is not a site typically amenable to limb-sparing surgery. In collaboration with Dr. Marcellin-Little at North Carolina State University, we developed a customized, 3D-printed titanium extraosseous transcutaneous partial amputation prosthesis (ETAP). A CT scan was performed of Bailey’s tibia, tarsus, and foot, and the STL files were sent to Dr. Marcellin-Little. Using computer-aided design principles in conjunction with the CT images, a customized ETAP was designed specifically for Bailey. This design was then 3D-printed using titanium as the layering material. The ETAP was then sent back for Bailey’s surgery. We performed a partial amputation of Bailey’s pelvic limb at the level of the distal tibia and then secured the ETAP to Bailey’s tibia (Figure 2).
Figure 2a. Postoperative lateral radiograph of Bailey’s customized 3D printed extraosseous transcutaneous partial amputation titanium prosthesis.
Figure 2b. Postoperative dorsoplantar radiograph of Bailey’s customized 3D printed extraosseous transcutaneous partial amputation titanium prosthesis.
Bailey recovered well from surgery and continues to enjoy excellent limb use, despite some challenges with the design of her prosthetic foot (Figure 3).
Figure 3. Bailey using the first iteration of her prosthetic foot. A new, more appropriate foot is currently being designed.
She has completed her chemotherapy course and has no evidence of metastatic disease. Bailey showed us that limb-sparing surgery can be individualized for each patient. By custom designing and conforming an implant for an individual patient, the risk of complications, especially implant-related problems, may be reduced because of reduced strain at the interfaces between the implant and host bone. Furthermore, limb-sparing options are no longer confined to the distal radius because implants can be customized to any anatomical location. As joint replacement technology improves, the ability to design and 3D print limb-sparing prostheses for the proximal humerus, proximal femur, distal femur, and proximal tibia are conceivable in the not too distant future.
Jagger, a 12-year-old, male neutered domestic short-haired cat, was diagnosed with a mandibular osteosarcoma. The mass had been conservatively excised on two previous occasions and recurred within 12 months on each occasion. The possibility of a mandibular prosthesis was discussed with the owner because of the well reported postoperative complications in cats following mandibulectomy where 72% of cats have eating difficulties for a median of 4 weeks following surgery and 12% of cats never eat again. This time we collaborated with Dr. Jonathan Bray at Massey University in New Zealand for the design and manufacture of a mandibular prosthesis. Dr. Bray has performed this procedure in three dogs with good results, but not cats. Using the same process as Bailey, a CT scan was performed and the STL files were sent to Dr. Bray. Based on these images, a customized mandibular prosthesis was designed and then 3D-printed using titanium as the layering material. Dr. Bray also designed and 3D-printed a plastic jig as an intraoperative guide for positioning the rostral and caudal osteotomies to perfectly fit the mandibular prosthesis. Intraoral and ventral approaches were made to Jagger’s mandible. The jig was secured and the rostral and caudal osteotomies were performed with guidance from the jig. Following removal of the mandibular segment, the intraoral incision was closed and the wound was copiously lavaged to minimize the risk of postoperative infection. The customized mandibular prosthesis was then inserted and fixed in position (Figures 4 and 5).
Figure 4. Intraoperative image of the customized 3D printed titanium mandibular prosthesis used to reconstruct Jagger’s mandible following mandibulectomy for excision of a mandibular osteosarcoma.
Figure 5. Postoperative ventrodorsal radiograph of Jagger’s customized 3D printed titanium mandibular prosthesis.
Jagger’s surgery was only performed 9 days ago; he started to eat one day after surgery and has continued to eat without difficulty since surgery. If reconstruction of the mandible following mandibulectomy continues to reduce the high complication rate following this procedure in cats, then customized, 3D-printed titanium mandibular prostheses will revolutionize the treatment of cats with mandibular tumors.
Bailey and Jagger are two examples of the advantages, both real and potential, of customized 3D printed titanium prostheses. Other than the obvious benefits to individual patients, there are a number of other benefits of 3D printing for medical applications. 3D-printed implants are a cost-effective alternative to traditional manufacturing processes, especially when the implants being printed are either customized to an individual patient or small-scale productions. The 3D printing process is much quicker than traditional manufacturing processes, which require milling, forging and long delivery times. As an example of the quick processing time with 3D-printed medical implants, Jagger’s titanium mandibular prosthesis was designed and printed within one week of receiving the CT images. The other very exciting development in 3D printing is the potential to incorporate nanoparticles into the printed implant to individualize treatment of patients. These nanoparticles could contain bone morphogenetic proteins to enhance osseous integration of the prosthesis, chemotherapy agents to achieve high local concentrations of chemotherapeutics to reduce the risk of local recurrence and metastasis, or antibiotics for slow release to minimize the risk of postoperative infection. While unlikely to be relevant in veterinary surgical oncology, 3D printing is also being investigated in combination with tissue engineering and regenerative medicine to produce vascularized cell-laden biomaterials for organ transplantation. In the meantime, the use of 3D printing technology will be important in the current trend of personalized medicine and provides many advantages for cats and dogs with cancer where implants can be customized to each patient, manufactured relatively cheaply and quickly, and potentially be associated with a reduced risk of complications.
Dr. Julius M. Liptak
BVSc, MVetClinStud, FACVSc, DACVS, DECVS
ACVS Founding Fellow in Surgical Oncology
Alta Vista Animal Hospital, Ottawa, Ontario, Canada
RECOVER – The Latest Advancements in Veterinary CPR
Keynote Speaker: Dr. Dan Fletcher, PhD, DVM, DACVECC
Associate Professor, Section of Emergency and Critical Care
Associate Chair of the Committee on Teaching and Clinical Service
Daniel Fletcher has been practicing veterinary medicine since 2003 with a focus on emergency and critical care. He received his DVM from the University of California at Davis. He went on to complete an internship in small animal medicine and surgery and a residency in emergency and critical care medicine from the University of Pennsylvania. He also holds a doctorate degree in biomedical engineering from the University of California at San Francisco and Berkeley. He is certified by the American College of Veterinary Emergency and Critical Care.
Sunday November 8th, 2015 8:30-3:30pm
8:30-9:00am: Registration and Breakfast
9:00-10:00am CPR: Everyone should be an Expert Part I- Dr. Dan Fletcher, DVM, DACVECC
The RECOVER initiative published the first evidence-based small animal CPR guidelines in 2012. What do we know about CPR in dogs and cats and what can you do to maximize the chance of a successful outcome if a patient arrests in your clinic? In dogs and cats with acute reversible disease leading to an arrest, as many as 50% can survive to discharge if high quality CPR is delivered quickly. This lecture will cover Basic and Advanced Life Support, and teach you what you need to know to maximize outcomes for your patients and your clients.
10:10-11:10am CPR: Everyone should be an Expert Part II-Dr. Dan Fletcher,
11:20-12:20pm: Post Resuscitation Care- Drs. Kim Slensky, DVM, DACVECC & Suzanne Donahue, VMD, DACVECC
You got the patient’s heart beating again, but this is just the beginning. Data in veterinary medicine suggests that as many as 85% of dogs and cats that received CPR are euthanized or die despite initial return of spontaneous circulation. Management of the post-arrest patient requires vigilant monitoring and the technical expertise of dedicated personnel. This lecture reviews the evidence found in the RECOVER guidelines regarding post-arrest care.
1:30-3:30pm Interactive CPR Wet Lab- Drs. Dan Fletcher, Kim Slensky and Suzanne Woodfin *Limited to the first 25 attendees*
In this interactive lab, teams of participants will run CPR scenarios using a high fidelity canine simulator with pulses, heart and lung sounds, and a patient monitor that displays real time ECG, end tidal carbon dioxide and pulse oximetry values. Participants will practice basic and advanced life support skills, and after each code will debrief with everyone in the lab to discuss what went well and what alternate approaches might have been preferred. Everyone in the lab will have an opportunity to participate in a scenario.
Sponsored by Hope Veterinary Specialists, Zoetis, and the Pennsylvania Veterinary Medical Association. This event is approved for five (5) CE credits through the PVMA. The seminar is being held at Hope Veterinary Specialists at 40 Three Tun Road, Malvern, PA 19355.
Please click on the Registration Button to attend this event.
*Please note this seminar will be limited to the first 60 attendees for the morning lecture portion and the first 25 VETERINARIAN attendees for the afternoon wet lab portion. Registration closes Wednesday November 4th. We regret that due to space limitations, we cannot accommodate onsite registration*
If you have any further questions, please contact Amy Shields at 610-557-1101