Laparoscopic real-time vessel navigation using indocyanine green fluorescence during the laparoscopic-Warshaw technique: First clinical experience.

BACKGROUND: Laparoscopic-Warshaw technique (lap-WT) may be selected as a function-preserving operation for malignant border lesions in the tail region of the pancreas. However, previous reports showed that there are complications such as infection and abscess formation due to lack of blood flow to the spleen after surgery. To overcome the problems, we have performed real-time vessel navigation by using indocyanine green (ICG) fluorescence during lap-WT.
MATERIALS AND METHODS: We report our experience of three patients with pancreatic tumour who underwent real-time vessel navigation during lap-WT at Hokkaido University from May 2017 to September 2018.
RESULTS: The median operating time was 339 min (174-420). The median intraoperative bleeding was 150 ml (0-480). There were no incidences of complications. There were no cases with post-operative spleen ischaemia or abscess formation and varices formation.
CONCLUSION: We believe that laparoscopic real-time vessel navigation using indocyanine green fluorescence during lap-WT could contribute in reducing the post-operative spleen-related complications.

INTRODUCTION

Laparoscopic-Warshaw technique (lap-WT) is an ideal procedure for selected patients with benign or low-grade malignant tumours in the body/tail of the pancreas. Preservation of spleen in distal pancreatectomy is useful for the maintenance of platelets and the prevention of overwhelming post-splenectomy infection.[1] However, there is the possibility of post-operative spleen-related complications such as infection and abscess formation due to lack of blood flow to the spleen.[2] We preserved the short gastric artery and vein, left gastroepiploic artery (LGEA) and vein and the connecting tissue around the splenic hiatus using laparoscopic real-time vessel navigation using indocyanine green (ICG) fluorescence during lap-WT. We believe that laparoscopic real-time vessel navigation using ICG during lap-WT serves as a useful technique in reducing post-operative spleen-related complications.

MATERIALS AND SURGICAL TECHNIQUE

From May 2017 to September 2018, we enrolled three consecutive patients who underwent lap-WT in the Department of Gastroenterological Surgery II at the Hokkaido University Hospital (Sapporo, Japan). All patients gave their informed consent to be included in the study. In a spleen-preserving distal pancreatectomy (SPDP), we had not indicated among patients with malignancies on pre-operative imaging, severe pancreatitis with or without pseudocyst or a relatively large tumour located at the hilum of the spleen. Where a malignancy was suspected, a splenectomy was always performed. Moreover, although the spleen-preserving distal pancreatectomy (LSPDP) with vessel preservation (lap-Kimura's method) is the first choice for laparoscopic LSPDP, because the cases showed difficulty in preserving the spleen vessels due to the presence of a tumour for spleen vessels attached to the spleen vessels, lap-WT was applied.

The patients were placed in the reverse Trendelenburg position as previously reported.[3] The first trocar was placed in the umbilicus, and an electro laparoscope (Karl Storz, Tuttlingen, Germany) was inserted into the peritoneal cavity. The intra-abdominal pressure was set at 10 mmHg. Under direct vision, a 12-mm trocar was inserted at the left paraxiphoid, followed by two 12-mm trocars in the bilateral subcostal areas and a 5-mm trocar along the left anterior axillary line (XCEL; Ethicon Endo-Surgery, Cincinnati, OH, USA) [Figure 1]. We verified that the splenic artery is ligated and cut to preserve the root of LGEA, and the preservation of the connecting around the splenic hiatus as much as possible. We used an near infrared (NIR) fluorescence laparoscopic system (Karl Storz, Tuttlingen, Germany). The system comprises a high-end full high-definition camera system (Image1 H3-Z 3-Chip Full HD camera, Karl Storz) connected to a 10-mm 30° ICG telescope (Hopkins™ II, Karl Storz). The perfusion pattern was noted and recorded. ICG dye (Diagnogreen; Dai-Ichi Pharm, Tokyo, Japan) was injected as a 5-mg bolus intravenously [Figure 2]. A stapler (Endo-GIA Tri-Staple, black cartridge; Covidien, Norwalk, CT, USA) was inserted through the right subcostal trocar and the pancreatic parenchyma was compressed and cut. Pulling the distal pancreas ventrally allowed for dissection around the splenic vessels at the splenic hilum. The connecting tissue around the splenic hiatus was preserved as much as possible. The specimen was retrieved in an endoscopic bag and extracted through the enlarged umbilical incision.

Figure 1

Positions of the surgical ports. Four 12-mm trocars are placed in the paraumbilical, bilateral abdominal and epigastric regions. One 5-mm trocar is placed in the left hypochondral area. ○; 12-mm trocar site, △; 5-mm trocar, ×; Umbilicus

Figure 2

(a) Intraoperative white light image. Arrows; left gastroepiploic artery, (b) Intraoperative fluorescence imaging visualising the fluorescent part of the left gastroepiploic artery. *Arrowheads; the fluorescent part connecting around the splenic hilum, Arrows; left gastroepiploic artery Panc; Pancreas, St; Stomach, Sp; Spleen

RESULTS

Table 1 shows the clinical characteristics and operative outcomes of the patients. All the three patients underwent lap-WT using real-time ICG fluorescence angiography. The patients' median age was 67 years (29–75), two males and one female, and the median body mass index was 21.9 kg/m2 (20.7–31.9). All patients had a diagnosis of mucinous cystic neoplasm, neuroendocrine tumour (G1) and intraductal papillary mucinous neoplasm. The median operating time was 339 min (174–420). The median intraoperative bleeding was 150 ml (0–480). The median splenic index[4] was 255 (240–300).

Table 1

Clinicopathological patient characteristics and operative outcomes (n=3)

	n
Clinicopathological patient characteristics
Age (years), median (range)	67 (29- 75)
Gender, male/female	2/1
BMI (kg/m2), median (range)	21.9 (20.7- 31.9)
Diagnosis (size)
MCN (50 mm)	1
IPMN (14 mm)	1
NET (9 mm)	1
Splenic index	255 (240- 300)
Operative outcomes
Operation time (min) median (range)	339 (174- 420)
Intraoperative blood loss (ml) median (range)	150 (0- 480)
Post-operative complications (CD ≥ III)	0
Pancreatic fistula (Grade ≥ B)	0
Splenic ischaemic change (CT)	0
Hospital stay after surgery (day), median (range)	11 (8- 12)

MCN: Mucinous cystic neoplasm, NET: Neuroendocrine tumour, IPMN: Intraductal papillary mucinous neoplasm, CD: Clavien-Dindo classification, BMI: Body mass index, CT: Computed tomography

There were no incidences of complications (≥Clavien–Dindo classification II). There were no cases of pancreatic fistula. The median length of hospital stay after surgery was 11 days (8–12). We confirmed of the LGEA and the connecting tissue including vessels around the splenic hiatus in all cases, and no findings such as post-operative spleen ischaemia or abscess formation in post-operative computed tomography (CT) findings. The post-operative follow-up CT findings showed no varices formation [Figure 3].

Figure 3

(a) Post-operative follow-up contrast-enhanced computed tomography (46 months after surgery). No varices formation was observed on the post-operative follow-up computed tomography. *Arrow; Stump of pancreas, b; Arrowheads; left gastric artery

DISCUSSION

Distal pancreatectomy with conservation of the spleen is becoming a widely used reductive surgery technique for benign/malignant borderline neoplastic lesions, metastatic pancreatic tumours and inflammatory diseases of the pancreatic tail. Moreover, along with the recent improvement of laparoscopic surgical techniques and development of devices, it has become possible to perform LSPDP, and there are several reports on LSPDP in which the splenic artery and vein are conserved.[5] The purposes of spleen preservation include avoidance of sepsis after splenectomy, prevention of severe post-operative infection, prevention of haematologic abnormalities such as thrombocytosis and associated thromboembolism and immunological protection from cancer.[6] Distal pancreatectomy conserving the spleen is broadly classified as a technique involving resection of the splenic artery and vein as reported by Warshaw (Warshaw technique)[7] and a technique of preserving the splenic artery and vein as reported by Kimura et al.[8] The Warshaw technique is not complicated and has the advantage of shortened operative duration. For spleen-preserving procedures, Nakata et al.[9] reported that lap-Kimura's method has better post-operative outcomes in terms of splenic complications compared to lap-WT. The spleen should be preserved in patients amenable to a spleen-preserving approach, and lap-Kimura's method is preferred to lap-WT even in minimally invasive surgery, if technically acceptable.

By contrast, it has been reported that the technique of conserving the splenic artery and vein can ensure conservation of the spleen, but the procedure is difficult, resulting in a large volume of haemorrhage and long operative duration. We generally perform lap-Kimura's method to ensure avoidance of splenic ischaemia and effective venous drainage from the spleen; however, we use lap-WT to preserve the splenic vessels in selected patients due to the presence of either a large tumour or a tumour attached to the splenic vessels. In addition, an approach that precedes the pancreatic dissection is used. This approach minimises dissection around the splenic hilum and is useful to conserve the vascular network.[2] Egorov et al.[10] reported that the LGEA is the least described artery in the medical literature and unusual variations of this artery might lead to vascular injuries, causing intraoperative bleeding after surgery. In the present study, it was possible to avoid post-operative complications related to splenic ischaemia by confirmation of LGEA and conservation of the connecting tissue including vessels around the splenic hilum, validating the utility of the NIR fluorescence laparoscopic system. Moreover, no varices formation was observed on the post-operative follow-up CT, suggesting that preserving the left gastroepiploic vein and the connecting tissue including vessels around the splenic hilum as well as LGEA may prevent post-operative varicose vein formation. We believe that the status of varicose vein formation needs to be followed up in the future. In the cases with splenomegaly or large tumours close to the splenic hilum, identification of LGEA may be difficult even with this novel technique. We plan to test the usefulness of this novel technique in a series of cases. This is the first reported study on using laparoscopic real-time vessel navigation with ICG fluorescence during lap-WT.

CONCLUSION

Laparoscopic real-time vessel navigation using ICG during lap-WT will contribute in reducing post-operative spleen-related complications.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.