Reconstruction surgery using polypropylene mesh after extensive resection of a costal osteosarcoma in a dog

Abstract

Osteosarcoma is the most common tumour that develops in the chest wall of dogs; an extensive excision is the treatment of choice. Various methods have been reported for reconstruction of chest wall defects following extensive excision.

The objective of this report was to describe the complete resection of an extensive costal osteosarcoma with an extended resection of the ribs and part of the diaphragm in a dog.

An 11-year-old neutered, male, miniature pinscher was presented with dyspnoea: An extensive mass was observed, stretching from the right chest wall to the abdominal wall. On computed tomography, the mass originated from the right 9th rib and exceeded the 6th rib on the cranial side and the 13th rib on the caudal side; it was compressing the lungs, diaphragm, liver, stomach and duodenum. When the patient's condition was medically stabilized, the tumour was removed from the right 9th rib. In consideration of the surgical margin, the 5th–13th ribs were excised, and the tumour was resected with the thoracoabdominal wall and part of the diaphragm. The missing thoracoabdominal wall and section of the diaphragm were reconstructed using two sheets of a polypropylene mesh. Postoperatively, flail chest was observed, although dyspnoea was not observed in the patient. Histopathological examination confirmed the diagnosis of osteosarcoma with a clean margin. Although 60.6 months have passed post-surgery, no metastasis has reoccurred.

In this case, complete resection and reconstruction of the chest wall and diaphragm were achieved using a polypropylene mesh without fatal postoperative complications, despite extensive osteosarcoma resection.

BACKGROUND

Osteosarcoma is the most common tumour that develops in the chest wall of dogs. The second most common chest wall tumour is chondrosarcoma, followed by fibrosarcoma and hemangiosarcoma (Feeney et al., 1982; Martano et al., 2012; Matthiesen et al., 1992; Pirkey-Ehrhart et al., 1995). Osteosarcoma occurs not only in the limb but also in the ribs, sternum, muscles that make up the chest wall and pleura. In addition, osteosarcoma of the ribs can invade the lungs and thoracic cavity. Diagnosis should be confirmed by biopsy with fine needle aspiration or Jamshidi needle biopsy. Surgical resection is the treatment of choice for these tumours. However, if the tumour increases in size or if it severely invades the thoracic cavity, an extended resection is required to secure a surgical margin. A maximum of six-to-seven ribs are reported to be removed in the excision of a costal tumour; if eight or more ribs are removed, a flail chest occurs (Liptak, Dernell et al., 2008). A flail chest results in an anomalous respiration that occurs when multiple ribs supporting the rib cage are lost, causing the defect to cave in, and, thereby, increasing the risk of respiratory failure and mortality (Athanassiadi et al., 2010). Few reports of resection of eight or more ribs for costal tumours have been reported (Martano et al., 2012).

Various methods have been reported for the reconstruction of chest wall defects following extensive excision. Use of a latissimus dorsi musculocutaneous flap (de Battisti et al., 2015) is effective for the reconstruction of the chest wall defects on the cranial side, and diaphragmatic advancement (Martano et al., 2012) is effective for reconstruction on the caudal side. Furthermore, reconstruction of the chest wall using a polypropylene mesh and plastic plates has also been reported (Liptak, Dernell et al., 2008). The combination of these methods could reconstruct a larger chest wall defect.

Objective

This case report describes the long-term survival of a dog with a large osteosarcoma of the chest wall that underwent a complete resection of the tumour and nine ribs, as well as reconstruction of the chest wall defect with a polypropylene mesh.

Case description

The patient was an 11-year-old neutered, male, miniature pinscher with a body weight of 3.8 kg and a body condition score of 2/5, based on a previous study (Baldwin et al., 2010). The patient was referred to a hospital because of a mass in the abdominal cavity revealed by ultrasonography a month earlier. Informed consent was obtained from the owner before all procedures were performed on the patient. At initial examination, tremor, respiratory distress and a poor body condition score were observed. Blood tests showed mildly decreased packed cell volume; elevated alkaline phosphatase, amylase, lipase, specific canine pancreatic lipase (Spec cPL) and C-reactive protein levels; and prolonged prothrombin time and activated partial thromboplastin time (Table 1). Chest radiography showed a radiopaque area similar to soft tissue on the right caudal thorax (Figure 1). Abdominal ultrasonography revealed an extensive mass of 8 cm in diameter in the abdominal cavity. No abnormalities in other organs were noted on ultrasound examination.

TABLE 1 Results of blood tests and blood chemistry tests in dog with rib tumour.

Parameter	Unit	Case	Normal range
RBC	106/µL	4.3	5.5–8.5
PCV	%	28	37–55
Hb	g/dL	9	12.0–18.0
WBC	/µL	17,500	6,000–17,000
Plt	103/µL	405	200–500
AST	U/L	47	0–50
ALT	U/L	23	10–100
ALP	U/L	685	23–212
GGT	U/L	7	0–7
TP	g/dL	6.8	5.2–8.2
Alb	g/dL	1.8	2.7–3.8
Glu	mg/dL	86	77–125
Tbil	mg/dL	0.3	0–0.9
BUN	mg/dL	20	7–27
Cr	mg/dL	0.6	0.5–1.8
Na	mEq/L	148	134–153
K	mEq/L	4.6	3.4–4.6
Cl	mEq/L	114	105–118
Amylase	U/L	2567	200–1400
Lipase	U/L	5152	137–721
Spec-CPL	µg/L	>1000	<200
CRP	mg/dL	12	0–1.0
PT	s	9.2	6.0–8.0
APTT	s	24.9	10.0–16.0
Fib	mg/dL	494.8	86–375
At	%	87	102–156

Abbreviations: Alb, albumin; ALP, alkaline phosphatase; ALT, alanine aminotransferase; APTT, active partial thromboplastin time; AST, aspartate aminotransferase; BUN, blood urea nitrogen; Cr, creatinine; CRP, C-reactive protein; Fib, fiblinogen; GGT, gamma-glutamyltransferase; Hb, haemoglobin; PCV, packed cell volume; Plt, platelet count; PT, prothrombin time; RBC, red blood cell count; Tbil, T-bililubin; TP, total protein; WBC, white blood cell count.

FIGURE 1. Right-lateral (a) and ventro-dorsal (b) thoracic radiograph (focus distance: 100 cm, 2.5 mA, 62 kV) demonstrating a radio-opaque mass occupying the right thoracic cavity. White arrows indicate tumour area.

Computed tomography (CT) was performed as follows: 0.04 mg/kg atropine (Mitsubishi Tanabe Pharma Co.) was injected subcutaneously (SC) as premedication; propofol (Mylan; Mylan Seiyaku Ltd.) was injected intravenously (IV) for anaesthetic induction for tracheal intubation, which was maintained with isoflurane (IsoFlo; Zoetis) and oxygen. Imaging was performed using a 16 multidetector CT scanner (Aquilion 16, Canon Medical Systems Co). The CT scan revealed a mass lesion measuring 11.1 cm × 9.1 cm × 7.9 cm (length × width × height), originating from the right ninth rib. The mass was swollen in the caudal direction, and the diaphragm, lung, liver and stomach were compressed by the large mass, along with the caudal vena cava (Figure 2). There were no metastatic findings in the lungs or other organs, and no mass lesions were observed in the other organs.

FIGURE 2. Contrast-enhanced computed tomography (CT) images of coronal image (a) and axial image (b) of the patient. The diaphragm, lung, liver and stomach are compressed by the large mass. White arrows indicate tumour.

Blood chemistry tests indicated a diagnosis of acute pancreatitis, and medical therapy was initiated, including oxygen therapy, IV infusion with 0.1 mg/kg/h nafamostat mesylate (Futhan; Mochida Pharmaceutical Co., Ltd.) and 2 mg/kg BID ranitidine (Ranitidine; Takeda Pharma CO., Ltd), and SC administration of 1 mg/kg maropitant (Cerenia; Zoetis). Additionally, glucose-added ringer's solution was administered at 3 mL/kg/h. On the third day, amylase (2,567–1,604; reference range: 200–1400 U/L) and lipase (5,152–939; reference range: 137–721 U/L) values decreased, and the patient's condition improved. The rib tumour was resected on day 5 after the initial visit.

Anaesthesia pre-administration in surgery was performed in the same manner as in CT examinations. In addition, 0.1 mg/kg fentanyl–droperidol (Thalamonal; Daiichi Sankyo Propharma Co., Ltd.) was administered IV as an analgesic. Following that, propofol was administered, and a tracheal tube was inserted. Thereafter, oxygen was mixed with approximately 1.5%–2% isoflurane (IsoFlo; Zoetis), and positive pressure ventilation was performed with a respirator. For intraoperative and postoperative analgesia management, continuous drip infusion of remifentanil (5–40 µg/kg/h) (Ultiva; Janssen Pharmaceutical K.K.) and pre- and postoperative SC injections of morphine (0.3 mg/kg for each dose) (Takeda Pharmaceuticals Co. Ltd.) were used.

The procedure was performed in the left lateral recumbent position, and the surgical site was approached through a right paracostal incision (Figure 3). After dissection of the subcutaneous tissue, the external oblique, internal oblique and transversus abdominis muscles were incised, dorsal to ventral to the abdominal cavity, while considering the caudal margin from the mass. The dorsal side of the 13th rib up to the 5th rib was resected using a sagittal saw (Nakanishi total surgical system Primado 2; Tokushima Iryoki Co. Ltd.). The mass was adherent from the right middle to caudal lobes of the right lung; therefore, the pulmonary veins, arteries and bronchi in the middle, and caudal lobes of the right lung were ligated with a 0 coated nylon braided suture (Surgilon; Medtronic Inc.). Thereafter, because part of the diaphragm had also adhered, the right diaphragm was incised, and the costal cartilage connection was excised to remove the mass from the thoracoabdominal wall, lung lobe, diaphragm and collective excision mass.

FIGURE 3. Surgery to remove a mass from the right ninth rib in a dog treated for an extensive costal osteosarcoma with resection and chest wall reconstruction using polypropylene mesh. In all the figures, the right is the cranial side, and the left is the caudal side. (a) Approach through a paracostal incision caudal to the 13th rib. (b) Incision through the external oblique abdominal muscle, internal oblique abdominal muscle and rectus abdominis muscle. (c) Resection of the 5th rib from the 13th rib. (d) Double ligation of the pulmonary vein and pulmonary artery in the middle lobe of the right lung. (e) Removal of a portion of the diaphragm that is adherent to the tumour. (f) After tumour removal by resection of the costochondral union on the ventral side of the tumour. (g) The diaphragm defect was filled with a polypropylene mesh. The black arrow indicates the diaphragm reconstruction area. (h) Entire thoracoabdominal wall covered with a polypropylene mesh. The black arrow indicates the part where the polypropylene mesh reconstructing the defect of diaphragm is sutured so as to separate the chest wall and the abdominal wall. (i) The drain tube was inserted, and the skin was routinely closed.

Because the defect in the chest wall extended from the thoracic to abdominal cavity and a part of the diaphragm was also missing, reconstruction was performed using a polypropylene mesh (PROLENE Mesh; Johnson & Johnson). First, a polypropylene mesh was formed into a fan shape to match the missing piece of the diaphragm. The apex of the fan shape and apex of the defect were joined using a simple ligation suture, performed using 3-0 polypropylene sutures (PROLENE; Johnson & Johnson). Thereafter, the two sides of the fan shape were sutured to align with the missing piece of the diaphragm. Next, a polypropylene mesh was fitted between the chest wall and abdominal wall defect sites, and a simple ligation suture was performed from the cranial direction with 3-0 polypropylene sutures. The mesh replacing the diaphragmatic defect and the mesh replacing the missing thoracoabdominal wall were sutured and covered, so as to separate the chest and abdominal walls. The mesh was then sutured to the defects in the abdominal and chest walls. Chest tubes and J-VAC drain (Johnson & Johnson) were placed in the thoracic cavity and SC, respectively. The polypropylene mesh was covered with the remaining latissimus dorsi and pectoralis major muscles, and the skin was routinely closed.

The operation lasted for 127 min and no intraoperative complications were observed. The postoperative course was good with continued evaluation of blood tests, chest radiography and respiratory disorder. Remifentanil was used as postoperative analgesia for about 3 days. Cefazolin (Kyoritsu) was used as an antibiotic, and intravenous infusion was administered. Although a flail chest was observed postoperatively due to the defects, there were no findings suggestive of dyspnoea. The chest tube was removed on postoperative day 12 along with the J-VAC drain because the amount of fluid and air being removed was also reduced. The patient was discharged from the hospital on postoperative day 12 in good general condition. The histopathological examination revealed the resected mass was diagnosed as osteosarcoma without any invasion into the surrounding tissues, including the lung and diaphragm, and a complete resection was achieved. The owner did not opt for the adjunctive chemotherapy, although we recommended the administration of doxorubicin and/or carboplatin. At the 60.6 postoperative months, the patient's condition was generally good, with no signs of dyspnoea or recurrence.

DISCUSSION

Osteosarcoma is the most common tumour of the ribs (Baines et al., 2002). Furthermore, the malignancy rate is higher than that of chondrosarcoma that also occurs in the ribs (Liptak, Kamstock et al., 2008). Therefore, the recurrence rate in incomplete resections is reported to be 6.7 times higher than in completely resected tumours (Liptak, Kamstock et al., 2008). Because tumour recurrence is a factor that worsens prognosis, a complete surgical resection is important for all rib tumours, including osteosarcoma. Surgical margins for rib tumours should include a minimum of one rib on the cranial and caudal sides of the tumour, and at least 3 cm on the ventral and dorsal sides (Baines et al., 2002; Liptak, Dernell et al., 2008). Because rib tumours often adhere to or infiltrate the lungs and pericardium, the removal of the surgical margins is recommended together with the rib tumours (Liptak, Dernell et al., 2008; Matthiesen et al., 1992). In this case, dyspnoea was caused by a massive osteosarcoma that developed on the right ninth rib of a dog. In the present case, after the rib tumour resection of an extensively enlarged osteosarcoma, the chest wall was reconstructed using a polypropylene mesh without any postoperative complications. Furthermore, considering the surgical margin and tumour infiltration, the resection of nine ribs and an en bloc resection of the middle and caudal lobes of the right lung were performed. A clean surgical margin was obtained as observed during histopathological examination.

Chest wall reconstruction after rib tumour excision involving a latissimus dorsi flap and diaphragm advancement has been reported. In the present case, the diaphragm and part of the latissimus dorsi muscle were resected to secure the surgical margin of the tumour; thus, this case excluded the possibility of future chest wall reconstruction. Polypropylene mesh was used to reconstruct the thoracoabdominal wall and diaphragmatic defect. Two sheets were used separately for the diaphragm and thoracoabdominal wall reconstruction. Although there are reports on the use of autologous fascia for diaphragm reconstruction (Suzuki et al., 2002), there are no reports on the use of mesh. In the present case, no occurrence of diaphragmatic hernia on radiograph was observed postoperation. Moreover, because elevated body temperature and granuloma were not observed on ultrasound examination, we inferred that mesh rejection had not occurred. Furthermore, because the extent of diaphragm defect due to excision of a tumour differs on a case-by-case basis, it is possible to mould the mesh to fit various defect sites. Moreover, there are many advantages of using a high-strength mesh. Reconstruction of the thoracoabdominal wall was likely to cause flail chest because nine ribs were removed; therefore, the length of the mesh and suture site were determined, so the mesh would be tensioned from the dorsal to ventral side to provide as much support tissue for the thorax as possible. When removing many ribs, reconstruction of the ribs using a rib or a plastic plate may be considered; however, because no suitably sized plate was found for this patient, polypropylene mesh and residual muscle were used for the reconstruction. After the surgery, flail chest occurred, although there were no symptoms such as dyspnoea, or any other major problems observed in daily life. Flail chest occurrence may have been reduced if the appropriate amount of tension was applied to the propylene mesh during the reconstruction of the thoracoabdominal wall.

The overall median survival time (MST) for osteosarcoma of the ribs is reported to be 290 days, with and without postoperative chemotherapy (Pirkey-Ehrhart et al., 1995). For surgery alone, the reported MST is 35–120 days, with a 6-month survival rate of less than 25% (Baines et al., 2002; Feeney et al., 1982; Matthiesen et al., 1992; Pirkey-Ehrhart et al., 1995). The MST will be prolonged by performing chemotherapy after surgery, although currently, no significant difference has been reported due to the small number of cases. Furthermore, recurrence worsens the prognosis, and there is a 25% risk of recurrence in incompletely resected cases (Bowman et al., 1998). Appendicular osteosarcoma has been reported to affect patient prognosis according to the histopathologic subtype, but primary rib osteosarcoma has been reported to be unaffected (Kirpensteijn et al., 2002; Loukopoulos and Robinson, 2007). In this case, 60.6 months have passed since the surgery, and no recurrence or distant metastasis has been observed; furthermore, long-term survival has been confirmed. Because there are various prognostic reports and cases such as this where long-term survival can be expected, complete resection is ideal for costal osteosarcoma (Liptak, Kamstock et al., 2008).

As a general limitation, the use of mesh in reconstruction is influenced by the breed and size of the dog, and further study is needed to apply the same method. Although this case showed a long-term prognosis, because no chemotherapy was used, more cases need to be evaluated regarding prognosis based on chemotherapy and margin evaluation.

Reports indicate that there was no specific bias in the location of rib tumours and no left-right difference (Liptak, Dernell et al., 2008). In cases where the rib tumour is more cranial in origin, an extended resection, such as in the current case, would not be indicated. However, the rate of infection caused using mesh has been reported to be 0%–5.7% (Benlloch-Gonzalez and Poncet, 2015; Liptak, Dernell et al., 2008), which is considered low, and, thus, may be an effective technique for large defects, such as the one in the present case.

CONCLUSION

In this case, complete resection and reconstruction of the chest wall and diaphragm were achieved using a polypropylene mesh without fatal postoperative complications, despite an extensive osteosarcoma resection with consideration of the surgical margin.

AUTHOR CONTRIBUTIONS

Conceptualization (supporting); data curation (supporting); visualization (supporting); writing – original draft preparation (equal); writing – review and editing (equal): Kei Tamura. Conceptualization (supporting); data curation (supporting); investigation (supporting); methodology (supporting); supervision (supporting); visualization (supporting); writing – original draft preparation (equal); writing – review and editing (equal): Kumiko Ishigaki. Data curation (supporting); investigation (supporting); writing – original draft preparation (equal): Naoki Sakurai and Tatsuya Heishima. Data curation (supporting); investigation (supporting); methodology (supporting); writing – original draft preparation (equal): Orie Yoshida. Conceptualization (lead); data curation (lead); investigation (lead); methodology (lead); supervision (lead); visualization (lead); writing – original draft preparation (equal); writing – review and editing (equal): Kazushi Asano.

ACKNOWLEDGEMENTS

We thank Dr. Minami Tsuyuki for supporting the surgery and the perioperative management.

CONFLICT OF INTEREST STATEMENT

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

FUNDING INFORMATION

No third-party funding or support was received in connection with this study or the writing or publication of the manuscript.

DATA AVAILABILITY STATEMENT

All data supporting the conclusions of this article are included within the article.

PEER REVIEW

The peer review history for this article is available at https://publons.com/publon/10.1002/vms3.1389.

ETHICS STATEMENT

The authors confirm that the ethical policies of the journal, as noted on the journal's author guidelines page, have been adhered to and the appropriate ethical review committee approval has been received.

PATIENT CONSENT STATEMENT

Informed consent was obtained from the owner before all the procedures performed on the patient.