Fig. 35.1
(a–d) (a) Port placement for laparoscopic right hepatectomy. (b) Port placement for laparoscopic left hepatectomy. (c) Port placement for laparoscopic distal pancreatectomy and splenectomy. (d) Port placement for robotic pancreaticoduodenectomy
Laparoscopic and Robotic Distal Pancreatectomy and Splenectomy
The term “distal pancreatectomy” applies to resection of the body and tail of the pancreas (left of the portal vein). Distal pancreatectomy is performed for various indications ranging from inflammatory processes such as chronic pancreatitis, trauma, as well as for benign and malignant neoplasms. Left-sided pancreatectomy was first performed in the late nineteenth century in Europe, notably in 1882 and 1884 by Trendelenburg and Billroth, respectively [16]. Von Mickulicz-Radecki attributed the slow development of pancreatic surgery to factors that remain relevant today: difficulty with exposure and access to the gland as well as difficulty with early diagnosis of pancreatic lesions. With advances in axial imaging and endoscopic and surgical techniques, pancreatic lesions can be diagnosed at an earlier stage and this has provided the ability to perform pancreatic resections in a minimally invasive fashion. Laparoscopic-assisted distal pancreatectomy was first described in the early 1990s by Sussman et al. for treatment of an insulinoma located in the tail of the pancreas [16]. Gagner and Pomp also reported their experience in minimally invasive pancreatic surgery in 1992; their described series included distal pancreatectomies as well as enucleation procedures performed laparoscopically for islet cell tumors of the left pancreas [16, 17].
Pancreatic lesions arising in the head and uncinate process have a greater chance for producing symptoms via mass effect at smaller sizes than do lesions of the body and tail of the pancreas [18]. Right-sided lesions and periampullary lesions commonly obstruct the common bile duct and lead to jaundice. The duodenum and distal pancreatic duct can also become obstructed. For this reason, new-onset pancreatitis in an older patient without gallstones or ethanol abuse necessitates pancreatic imaging to rule out a mass. Lacking these classic obstructive symptoms seen in comparatively smaller right-sided tumors, left-sided pancreatic masses have been historically diagnosed only at a larger size than those on the right [18, 19]. Retrospective reviews of pancreatic resections performed at high-volume pancreatic surgical centers continue to show statistically larger left-sided lesions compared to those on the right [18]. Vague symptoms including a dull abdominal pain may be present; less common manifestations such as new-onset diabetes mellitus, pancreatitis in the absence of gallstones or ethanol use, and fat malabsorption are also described. Given the typically larger size of left-sided lesions at the time of diagnosis, there is a higher chance of locally advanced tumors with invasion or compression of surrounding vascular, neural, and visceral structures.
Distal pancreatectomy has classically been performed with concomitant splenectomy for multiple reasons. The splenic vasculature travels along the length of the pancreatic body and tail with the splenic vein closely adherent to the posterior parenchyma of the gland; veins from the body and tail of the pancreas drain directly into the splenic vein. The splenic artery lies posterior to the pancreas but follows a more variable and ectatic course than the vein. The tail of the pancreas terminates in the hilum of the spleen in many patients and tail lesions may involve the vessels within the hilum or the spleen itself from direct extension. Resection of the tail for these reasons may risk splenic devascularization or incomplete pancreatic parenchymal resection from the hilum. The lymphatic drainage of the pancreas is perhaps the most crucial factor considered in splenectomy for malignant lesions of the body and tail of the pancreas [20, 21].
Distal pancreatectomy with splenectomy is currently being performed more commonly via a laparoscopic technique since this procedure was introduced in the early 1990s. A spleen-preserving technique can be considered for benign lesions and for traumatic injuries to the pancreas if the splenic vascular structures can be preserved. With increasing experience in performing this procedure laparoscopically, morbidity rates and other postoperative factors seem to mirror the benefits seen in other laparoscopic surgeries [22].
Another procedure developed for traumatic parenchymal injury with ductal disruption or low-grade neoplastic processes such as islet cell tumors is the central pancreatectomy. Central pancreatectomy removes a central segment of the body and results in two exposed portions of the pancreatic duct. This is a parenchyma-sparing procedure compared with a distal pancreatectomy performed for a discrete lesion in the pancreatic body. The right-sided duct can be oversewn as described in the description of a distal pancreatectomy with a Roux limb of bowel anastomosed to the distal duct to facilitate drainage; the wall of the Roux limb can be used as a seromuscular patch to the proximal stump.
For malignant lesions of the distal pancreas, Strasberg et al. in 2003 described the radical antegrade modular pancreatosplenectomy (RAMPS), a procedure designed to resect tumors arising from the left pancreas using existing fascial planes to achieve a negative margin and to include all draining lymph nodes [20]. Dissecting within retroperitoneal fascial planes and including all draining lymph nodes was proposed to emulate the surgical techniques that had been developed for pancreaticoduodenectomy for treatment of right-sided pancreatic malignancy. Unlike the traditional distal pancreatectomy, the dissection for a RAMPS procedure begins by dissecting around the neck of the pancreas and proceeds in a right-to-left direction. Two versions of the procedure are described, anterior and posterior, and differ based on tumor penetration of the posterior capsule of the pancreas; when penetration is not seen on preoperative imaging, the dissection is performed anterior to the left adrenal and proceeds along the anterior aspect of Gerota’s fascia. In cases of tumor extension beyond the posterior capsule of the pancreas, the dissection is taken through Gerota’s fascia, sacrifices the left adrenal gland, and is carried down to the capsule of the left kidney itself. The dissection includes the peri-pancreatic nodes as well as the para-aortic and celiac nodes that serve as primary and secondary drainage for the body and tail of the pancreas. This procedure was originally described as an open procedure and is now being performed laparoscopically.
For malignant tumors of the body of the pancreas that have invaded the celiac axis, distal pancreatectomy with resection of the celiac axis (DP-CAR), commonly referred to as the modified Appleby procedure, is described. The original Appleby procedure was performed in 1953 for locally advanced gastric adenocarcinoma with extension into the celiac axis. This procedure purposefully occludes and ligates the celiac artery, an action that acutely halts the usual pattern of arterial blood flow to the stomach and liver. The celiac and common hepatic arteries are ligated in this step, and blood flow to the liver is maintained via collateral circulation from the SMA and the pancreatoduodenal arcade that restores blood flow to the proper hepatic artery through the gastroduodenal artery. Some centers perform preoperative embolization of the common hepatic artery to induce maturation of the pancreatoduodenal collaterals. Bypass grafts from the aorta and iliac artery to the common hepatic have also been performed primarily or when poor pulsation or lack of back-bleeding has been observed intraoperatively. Though many series have evaluated the immediate postoperative period of patients undergoing the modified Appleby procedure, little data is present on long-term survival and evidence of disease recurrence [18, 20].
Surgical Technique
The laparoscopic technique follows the same principles as the open procedure and we prefer to do our dissection from the medial to lateral aspect. After gaining access into the patient’s abdomen and obtaining adequate pneumoinsufflation (Fig. 35.1c), the abdominal cavity is carefully inspected for evidence of metastatic spread. Once the disease is confirmed to be involving only the pancreas, the lesser sac is entered by dividing the attachments between the greater curvature of the stomach and the transverse colon to expose the anterior surface of the pancreas. A laparoscopic vessel-sealing device is used for this purpose. The peritoneal attachments to the inferior and superior borders of the pancreas are divided with care taken to identify the inferior mesenteric vein in the inferior peritoneal attachments. An intraoperative ultrasound is routinely performed to confirm the location of the tumor. Alternatively, a hand port can be placed and the gland is palpated for the tumor. The splenic artery is identified by intraoperative ultrasound to the left of the celiac; the hepatic arteries and other branches from the celiac axis are also identified and traced via ultrasound prior to arterial ligation. Meticulous dissection is performed to adequately mobilize the pancreas from its retroperitoneal attachments. The inferior mesenteric vein on the inferior border of the pancreas is exposed and ligated. The splenic vein is also visualized at this point in time and it is carefully dissected off the inferior aspect of the pancreas prior to dividing it with a vascular stapler at its junction with the portal vein. As the dissection continues from a medial to lateral aspect, the left adrenal gland is commonly encountered. Dissection anterior to the adrenal or posterior to the adrenal with inclusion of the gland in the resected specimen depends on the gross involvement of the gland by tumor seen at the time of surgery or based on preoperative imaging showing preservation or loss of the plane between the pancreas and adrenal. In cases of a posterior tumor, the adrenal may be resected en bloc with the pancreas. The spleen is mobilized by dividing the gastrosplenic ligament which includes the short gastric vessels as well as the splenocolic attachments. For a known malignancy, ligation of the ligament is performed close to the wall of the stomach to include all nodes within the ligament. The pancreas is generally transected with a stapling device at the level of the portal vein. Sometimes, the gland is divided using laparoscopic bipolar electrosurgery device and the pancreatic duct is oversewn with nonabsorbable suture. The specimen is retrieved via the hand port site or one of the laparoscopic ports is enlarged to do the same. Hemostasis is obtained and a closed suction drain is left adjacent to the cut end of the pancreas.
Minimally Invasive Pancreaticoduodenectomy
The first laparoscopic pancreaticoduodenectomy was performed in 1994 by Ganger and Pomp for a patient with chronic pancreatitis [23]. The operation took about 10 h to complete. The next case series to come out with outcomes in ten patients was in 1997 by Ganger and Pomp again [24]. There was a 40 % conversion rate which made the surgeons question the benefit of laparoscopy for pancreaticoduodenectomy. With the advancement in technology (laparoscopy and robotics) and refinement of surgical instruments including enhanced optics, there was a renewed interest amongst surgeons. The first case series on robotic pancreatic resections by Giulianotti et al. was published in 2003 in Europe [25]. Melvin and Needleman reported their experience with robotic resection of a pancreatic neuroendocrine tumor in the United States at the same time [26]. Kendrick et al. published their series from the Mayo Clinic in Rochester on the safety and efficacy of total laparoscopic pancreaticoduodenectomy. Their case series involved a total of 65 patients with a mean age of 66 years. The average operative time was 368 min and median blood loss was 240 ml. The perioperative morbidity mainly consisted of delayed gastric emptying (n = 9), pancreatic fistula (n = 11), and bleeding (n = 5). The median length of stay was 7 days. Based on the results, they concluded that laparoscopic pancreaticoduodenectomy was feasible, safe, and effective [27]. The recent systemic review and meta-analysis of studies comparing minimally invasive pancreaticoduodenectomy to open pancreaticoduodenectomy by Camilo Correa-Gallego et al. concluded that the minimally invasive approach was feasible in select patients at select centers. The outcomes were comparable to that of the open procedure based on the 6 studies that included 542 patients (169 minimally invasive and 373 open) [28].
Based on the current literature published, it is safe to say that minimally invasive pancreaticoduodenectomy is technically feasible and has similar outcomes as the open procedure. Further studies are warranted to determine patient recovery and quality of life especially in the group of patients that require adjuvant therapy after surgery.
Surgical Technique
At our institution the robot is used to perform minimally invasive pancreaticoduodenectomies. Our technique usually involves the patient being positioned in a supine fashion. After intubation and prepping and draping the field, pneumoinsufflation is obtained with a Veress needle at the umbilicus and subsequently upsized to a 12 mm port three additional 8 mm cannulas as well as an additional 12 mm camera port (in the right midclavicular line) are placed under direct vision (Fig. 35.1d). The umbilical trocar site serves as the assistant port during most of the resection portion of the procedure. Upon initial entry the abdominal cavity is always inspected for evidence of metastatic disease. The robotic shears are then used to mobilize the round and falciform ligaments off of the anterior abdominal wall. These are used at the end of the case as a vascularized pedicle flap with which we wrap the pancreaticojejunostomy for reinforcement [29]. The inferior border of the distal gastric antrum and proximal duodenum is mobilized with care to avoid injury to the distal gastric antrum or the pylorus.
We then identify the origin of the right gastroepiploic blood vessels. These are dissected out and then sealed and divided using the robotic vessel-sealing device. Similarly, the superior border of the distal gastric antrum is identified and the right gastric artery pedicle is sealed with a vessel-sealing device and divided at its origin from the proper hepatic artery. We then mobilize the remainder of the proximal duodenum which is subsequently stapled and divided using a laparoscopic 60 mm linear stapler. The stomach is placed in the left upper quadrant for reconstruction at the end of the case. The hepatic flexure and transverse colon and omentum are mobilized away from the anterior face of the pancreas and the duodenum. An extended Kocher maneuver is performed by mobilizing the duodenum away from its retroperitoneal attachments until the duodenum and pancreas are freed from the inferior vena cava and the aorta. The ligament of Treitz is mobilized using the robotic vessel-sealing device to facilitate the small bowel to flip up underneath the mesenteric vessels to the right upper quadrant. The common hepatic artery is dissected out and the portal and celiac lymph nodes are mobilized off the blood vessels. An extensive lymphadenectomy is performed along the posterior and medial aspect of the porta hepatis and sent separately for permanent pathological examination. Similarly, the common hepatic artery lymph node and the proximal celiac lymph nodes are dissected off the blood vessels and sent separately for pathological examination. An intraoperative ultrasound is performed to confirm the vascular anatomy of the porta hepatis. The gastroduodenal artery is identified and then clipped and divided using locking plastic clips. This allows one to mobilize hepatic artery proper away from the common hepatic duct. The inferior border of the pancreas and the neck are dissected out and mobilized. A tunnel is created underneath the neck of the pancreas, anterior to the superior mesenteric and portal vein to the superior aspect of the pancreas. An umbilical tape is passed beneath the pancreas. At this point, the neck of the pancreas is transected using the robotic monopolar scissors coupled with saline irrigation to minimize charring of the tissue.
The small bowel is transected approximately 20 cm distal to the ligament of Treitz, and the small bowel mesentery is taken with a robotic vessel-sealing device towards the base of the uncinate process. Finally, the uncinate process is mobilized away from the superior mesenteric vein and the superior mesenteric artery. The common hepatic duct is then transected just above the cystic duct takeoff. The cystic artery is identified as a discrete branch coming off the right hepatic artery. This is sealed and divided using the vessel-sealing device. The gallbladder is then taken off the undersurface of the liver using the monopolar robotic shears. The entire specimen is then placed into an Endo Catch™ bag (Covidien, Minneapolis, MN) and retrieved from the abdominal cavity from the slightly enlarged umbilical trocar site. The trocar site is closed using interrupted figure-of-eight 0 PDS sutures.
For the reconstruction phase of the procedure, the stapled end of the jejunum is brought alongside the transected surface of the pancreas. The posterior pancreaticojejunostomy layer is performed using 4-0 absorbable suture in a running fashion. A small enterotomy matching the diameter of the pancreatic duct is created in the jejunum with the and a duct to mucosal anastomosis is performed using interrupted 6-0 absorbable sutures over an 8 French pediatric feeding tube cut to approximately 6 cm. The anterior pancreaticojejunostomy is completed using an additional 4-0 absorbable suture in a running fashion. The entire anastomosis is then wrapped with the round ligament pedicle flap and reinforced with a fibrin sealant.
The hepaticojejunostomy is performed approximately 10–15 cm distal to the pancreaticojejunostomy using a 4-0 absorbable suture in a running or interrupted fashion, depending on the size of the duct. The antecolic duodenojejunostomy is performed approximately 50 cm from the biliary anastomosis using absorbable suture. A 19 French closed suction drain is placed in the right upper quadrant close to the biliary and pancreatic anastomoses. All the port sites are closed with absorbable suture.
Thermal Ablation and Chemical Injection
Ablation technology, which involves the destruction of tumor in situ, has become a mainstay form of treatment of tumors in the liver, kidney, lungs, and other solid organs. Ablative modalities for hepatic malignancy include chemical injection (via alcohol and acetic acid) and thermal methods (cryoablation using liquid nitrogen and argon, coagulative destruction using radiofrequency, microwave, laser, and HIFU). The newer technology includes irreversible electroporation which causes destruction of tumor by cellular reprogramming.
Ablation is primarily indicated for unresectable hepatic tumors though this concept is changing with the advancements in ablation technology and published literature showing excellent survival rates and low rates of recurrence in patients with potentially resectable tumors [30]. It has become one of the primary modalities of choice in patients with hepatocellular carcinoma and underlying cirrhosis who are awaiting a transplant. As the experience in ablating HCC has grown, the technology has also been used for other liver tumors such as adenomas, cholangiocarcinoma, and metastatic lesions with results equivalent to resection. There is no actual size limit on the lesion chosen for ablation but expert advise applying the technology to lesions 4 cm or less and those not in close proximity to major bile ducts for the best oncological response.
Cryoablation
From a historical perspective, ablation was first started in combination with cryogenics. In 1963 Cooper used cryosurgery to treat Parkinson’s disease [31, 32]. Soon, the idea of treating primary and metastatic liver tumors using a vacuum insulated probe cooled by liquid nitrogen was conceived. The theory behind the application was that the probe would make rapid extraction of heat possible while freezing the tumor in situ. Despite the promising results achieved initially, cryoablation was limited to use on superficial tumors since there was no way to visualize deep seated tumors or surrounding structures in real time. The advent of intraoperative ultrasound in the 1990s made precise identification and ablation of intrahepatic tumors possible. As the technology improved over the next decade, laparoscopy was introduced into the world of surgery and soon enough with newly designed probes, ablation was made possible in conjunction with laparoscopy [33].
Cryoablation has its set of limitations. The time taken to complete a single ablation is close to 30–40 min. Some of the complications associated with cryoablation include bile leaks and excess bleeding. One of the major complications is termed “cryoshock” where a patient develops acute renal failure, acute respiratory distress syndrome, disseminated intravascular coagulation, and liver failure. With the advancement in ablation technology using radiofrequency and microwaves, cryotherapy has fallen out of favor amongst liver surgeons. Nonetheless, the technology is currently being used in conjunction with immunotherapy in the treatment of unresectable breast and hepatocellular cancer in a few centers [34, 35].
Radiofrequency Ablation
Radiofrequency ablation was first approved for use in the liver by the FDA in 1997 though its clinical applications had started two decades earlier. The main mechanism of tissue destruction is causing hyperthermia via radiofrequency waves. The technology relies on the interaction of an alternating current with tissue during which ions become agitated secondary to the high frequency waves (460–480 kHz), and the heat generated in the process causes coagulative necrosis [36, 37]. The entire process is controlled via an external generator based on continuous real-time measurement of tissue impedance. The radiofrequency probes have various designs the most common ones being needle electrodes with multiple extendable metal tines and single or clusters of internally cooled straight needles that pass electricity through the tissues between grounding pads applied to the patient (monopolar) or to a second probe inserted a short distance away (bipolar).
The incidence of bile leaks and bleeding is minimal when performed carefully under ultrasound guidance and there is no phenomenon similar to cryoshock that exists with radiofrequency. On the other hand, one of the major limitations is the “heat sink” effect where the hyperthermia caused by the antenna is reduced at the periphery by the blood flowing through the tissue. This raises the concern of leaving viable tumor cells behind at the periphery and between tines. The result of the effect can be negated by performing overlapping ablations and ensuring the complete destruction of the tumor. Radiofrequency ablation remains the most common thermal ablation technique used currently to treat primary and metastatic tumors.