Minimally invasive surgery, a widely adopted tool for most domains of gastrointestinal surgery, has been relatively slow to evolve in the field of pancreatic surgery. The reasons include proximity to the great vessels, retroperitoneal location, need for advanced intracorporeal suturing skills and increased risk of complications associated with these procedures. With enormous development in surgical technology coupled with improved anatomical knowledge and refined skills, minimally invasive pancreatic surgery has grown out of its infancy and is an established specialty in hepato-pancreato-biliary surgery today. As a result, the initial scepticism and reluctance associated with minimally invasive pancreatic resections has decreased and many surgeons are attempting to enter this difficult terrain. Recent publications highlight potential advantages of minimally invasive pancreatic resection (MIPR) over open pancreatic resection (OPR). These include reduced pain, decreased blood loss and need for transfusion, an earlier return of bowel function, decreased wound infection rates and shorter intensive care unit and overall hospital stays. Though the number of minimally invasive pancreatic resections performed for benign and malignant diseases of the pancreas has increased in recent years, cost considerations and financial implications of these new approaches need to be well defined. Clear guidelines and standardization of surgical technique are paramount for the safe and steady expansion of this novel surgical approach.
Minimally Invasive Pancreaticoduodenectomy
Gagner and Pomp reported the first LPD in 1994. They felt that laparoscopy was not useful for such a major resection and reconstruction. However, their initial patients included those with chronic pancreatitis, where LPD is considered difficult to do even at present. With this background, we began doing LPD after sufficient experience had been gained in other major laparoscopic procedures such as colectomy, gastrectomy and choledochal cyst excision. During the initial phase, LPD was attempted in only periampullary tumours or small pancreatic head masses. With increasing experience, the indications for LPD were expanded to include carcinoma head of the pancreas and larger tumours.
Over the years, numerous technical modifications in terms of surgeon comfort, use of energy source, radicality of surgery, type of reconstruction and specimen extraction were made. These refinements resulted in better outcomes as was evident in the next publication in 2009 which included 75 patients. Oncologically, the resection status and lymph nodal yield were comparable with the open approach and would translate to equal survival outcomes. Recently, Asbun et al. compared their open PDs and LPDs and found that LPD had better perioperative outcomes in terms of blood loss and ICU and hospital stays.
In 2015, Palanivelu reported that the pathological radicality of LPD was comparable to that of the open approach when performed by experienced minimal access surgeons. And analysed yours long-term outcomes following LPD in 130 patients with pancreatic and periampullary cancers. This study, one of the largest published series so far, showed excellent short-term results and acceptable long-term survival. The pancreatic fistula rate was 8.5%, mean (SD) operating time was 310 (34) min, and mean blood loss was 110 (22) ml with a mean hospital stay of 8 (2.6) days. The resected margins were positive in 9.2% with an overall 5-year actuarial survival of 29.4% and a median survival of 33 months.
Published outcomes of LPD have shown that it is feasible and safe when done in high-volume institutions by expert surgeons. In a recent systematic review of LPD, Boggi et al. identified 25 articles with 746 patients who had LPD for both malignant and benign indications. The mean operative time and estimated blood loss were 464 min and 321 ml, respectively. Conversion to open surgery was required in 9% of patients. The average hospital stay was 14 days. The overall morbidity, mortality and pancreatic fistula rates were 41.2, 1.9 and 22.3%, respectively. The majority of surgeons did a pancreaticojejunostomy (84%), whereas a small number did pancre- aticogastrostomy (9.8%) or duct occlusion (6.8%). A slight majority did pylorus preservation (55%) instead of hemigastrectomy (45%). No major differences in outcomes were seen for laparoscopic, robotic, laparoscopic-assisted or hand-assisted methods.
Similarly, no significant differences were seen between high-volume (>30 cases) and low-volume centres other than longer operative times and higher estimated blood loss in the low-volume ones. The average number of lymph nodes recovered was 14.4 and the negative margin rate was 95.6%. Although the data were heterogeneous with a high likelihood for selection bias, the results for LPD appear to be at least comparable to those in patients undergoing open PD.
In general, LPD was associated with reduced blood loss and hospital stay; however, operative times tend to be longer. The longer operative times associated with LPD tend to reduce with increasing experience. In a series by Kim et al., the median operative time for LPD was 7.9 h and decreased with accumulating experience of the surgeon doing this procedure from 9.8 h for the first 33 cases to 6.6 h for the last 34 cases.