Indocyanine green fluorescence in gastrointestinal surgery:Appraisal of current evidence

Applying indocyanine green(ICG)fluorescence in surgery has created a new dimension of navigation surgery to advance in various disciplines.The research in this field is nascent and fragmented,necessitating academic efforts to gain a comprehensive understanding.The present review aims to integrate diverse perspectives and recent advances in its application in gastrointestinal surgery.The relevant articles were selected by using the appropriate keyword search in PubMed.The angiography and cholangiography property of ICG fluorescence is helpful in various hepatobiliary disorders.In gastroesophageal and colorectal surgery,the lymphangiography and angiography property of ICG is applied to evaluate bowel vascularity and guide lymphadenectomy.The lack of objective parameters to assess ICG fluorescence has been the primary limitation when ICG is used to evaluate bowel perfusion.The optimum dose and timing of ICG administration need to be standardized in some new application areas in gastrointestinal surgery.Binding tumor-specific ligands with fluorophores can potentially widen the fluorescence application to detect primary and metastatic gastrointestinal tumors.The narrative review outlines prior contributions,limitations,and research opportunities for future studies across gastrointestinal sub-specialty.The findings of the present review would be helpful for scholars and practitioners to explore and progress in this exciting domain of gastrointestinal surgery.

Changing trends in the minimally invasive surgery for chronic pancreatitis

Chronic pancreatitis is a debilitating pancreatic inflammatory disease characterized by intractable pain resulting in poor quality of life.Conventional management of pancreatic pain consists of a step-up approach with medications and lifestyle modifications followed by endoscopic intervention.Traditionally surgery is reserved for patients who do not improve with other interventions.However,recent studies suggest that early surgical intervention is more beneficial as it can mitigate the progression of the pathological process and prevent loss of pancreatic function.Despite the widespread adoption of minimally invasive approaches in various gastrointestinal surgical disorders,minimally invasive surgery for chronic pancreatitis is slow to evolve.Technical difficulty due to severe inflammatory changes has been the major impediment to the widespread usage of minimally invasive surgery in chronic pancreatitis.With this background,the present review aimed to critically analyze the available evidence on the minimally invasive treatment of chronic pancreatitis.A Pub Med search of all relevant articles was performed using the appropriate keywords,parentheses,and Boolean operators.Most initial laparoscopic series have reported the feasibility of lateral pancreaticojejunostomy,considered an adequate procedure only in a small proportion of patients.The pancreatic head is the pacemaker of pain,so adequate decompression is critical for long-term pain relief.Recent studies have documented the feasibility of minimally invasive duodenum-preserving pancreatic head resection.With improvements in laparoscopic instrumentation and technological advances,minimally invasive surgery for chronic pancreatitis is gaining momentum.However,more high-quality evidence is required to document the superiority of minimally invasive surgery for chronic pancreatitis.

Radiological parameters to predict pancreatic texture:Current evidence and future perspectives

Preoperative prediction of the postoperative pancreatic fistula risk is critical in the current era of minimally invasive pancreatic surgeries to tailor perioperative management,thereby minimizing postoperative morbidity.Pancreatic duct diameter can be readily measured by any routine imaging used to diagnose pancreatic disease.However,radiological evaluation of pancreatic texture,an important determinant of pancreatic fistula,has not been widely used to predict the risk of postoperative pancreatic fistula.Qualitative and quantitative assessment of pancreatic fibrosis and fat fraction provides the basis for predicting pancreatic texture.Traditionally computed tomography has been utilized in identifying and characterizing pancreatic lesions and background parenchymal pathologies.With the increasing utilisation of endoscopic ultrasound and magnetic resonance imaging for evaluating pancreatic pathologies,elastography is emerging as a promising tool for predicting pancreatic texture.Also,recent studies have shown that early surgery for chronic pancreatitis is associated with better pain relief and preservation of pancreatic function.Pancreatic texture assessment can allow early diagnosis of chronic pancreatitis,facilitating early intervention.The present review outlines the current evidence in utilizing various imaging modalities for determining the pancreatic texture based on different parameters and image sequences.However,multidisciplinary investigations using strong radiologic-pathologic correlation are needed to standardize and establish the role of these non-invasive diagnostic tools in predicting pancreatic texture.

Appraisal of gastric stump carcinoma and current state of affairs

Gastric stump carcinoma,also known as remnant gastric carcinoma,is a malignancy arising in the remnant stomach following gastrectomy for a benign or malignant condition.Enterogastric reflux and preexisting risk factors in a patient with gastric cancer are the major contributors to the development of gastric stump carcinoma.The occurrence of gastric stump carcinoma is time-dependent and seen earlier in patients operated on for malignant rather than benign diseases.The tumor location is predominantly at the anastomotic site towards the stomach.However,it can occur anywhere in the remnant stomach.The pattern of lymph node involvement and the type of surgery required is distinctly different compared to primary gastric cancer.Gastric stump carcinoma is traditionally considered a malignancy with a dismal outcome.However,recent advances in diagnostic and therapeutic strategies have improved outcomes.Recent advances in molecular profiling of gastric stump carcinoma have identified distinct molecular subtypes,thereby providing novel therapeutic targets.Also,reports of gastric stump carcinoma following pancreatoduodenectomy and bariatric surgery highlight the need for more research to standardize the diagnosis,staging,and treatment of these tumors.The present review aims to provide an overview of gastric stump carcinoma highlighting the differences in clinicopathological profile and management compared to primary gastric carcinoma.

Minimally invasive surgery for post cholecystectomy biliary stricture:current evidence and future perspectives

Postcholecystectomy bile duct injury(BDI)remains a devastating iatrogenic complication that adversely impacts the quality of life with high healthcare costs.Despite a decrease in the incidence of laparoscopic cholecystectomy-related BDI,the absolute number remains high as cholecystectomy is a commonly performed surgical procedure.Open Roux-en-Y hepaticojejunostomy with meticulous surgical technique remains the gold standard surgical procedure with excellent longterm results in most patients.As with many hepatobiliary disorders,a minimally invasive approach has been recently explored to minimize access-related complications and improve postoperative recovery.Since patients with gallstone disease are often admitted for a minimally invasive cholecystectomy,laparoscopic and robotic approaches for repairing postcholecystectomy biliary stricture are attractive.While recent series have shown the feasibility and safety of minimally invasive post-cholecystectomy biliary stricture management,most are retrospective analyses with small sample sizes.Also,long-term follow-up is avail-able only in a limited number of studies.The principles and technique of minimally invasive repair resemble open repair except for the extent of adhesiolysis and the suturing technique with continuous sutures commonly used in minimally invasive approaches.The robotic approach overcomes key limitations of laparoscopic surgery and has the potential to become the preferred minimally invasive approach for the repair of postcholecystectomy biliary stricture.Despite increasing use,lack of prospective studies and selection bias with available evidence precludes definitive conclusions regarding minimally invasive surgery for managing postcholecystectomy biliary stricture.High-volume prospective studies are required to confirm the initial promising outcomes with minimally invasive surgery.

Changing trends in the minimally invasive surgery for corrosive esophagogastric stricture

Esophagogastric stricture is the troublesome long-term complication of corrosive ingestion with a significant adverse impact on the quality of life.Surgery remains the mainstay of therapy in patients where endoscopic treatment is not feasible or fails to dilate the stricture.Conventional surgical management of esophageal stricture is open esophageal bypass using gastric or colon conduit.Colon is the commonly used esophageal substitute,particularly in those with high pharyngoesophageal strictures and in patients with accompanying gastric strictures.Traditionally colon bypass is performed using an open technique that requires a long midline incision from the xiphisternum to the suprapubic area,with adverse cosmetic outcomes and long-term complications like an incisional hernia.As most of the affected patients are in the second or third decade of life minimally invasive approach is an attractive proposition.However,minimally invasive surgery for corrosive esophagogastric stricture is slow to evolve due to the complex nature of the surgical procedure.With advancements in laparoscopic skills and instrumentation,the feasibility and safety of minimally invasive surgery in corrosive esophagogastric stricture have been documented.Initial series have mainly used a laparoscopic-assisted approach,whereas more recent studies have shown the safety of a total laparoscopic approach.The changing trend from laparoscopic assisted procedure to a totally minimally invasive technique for corrosive esophagogastric stricture should be carefully disseminated to preclude adverse longterm outcomes.Also,well-designed trials with long-term follow-ups are required to document the superiority of minimally invasive surgery for corrosive esophagogastric stricture.The present review focuses on the challenges and changing trends in the minimally invasive treatment of corrosive esophagogastric stricture.

Diabetes and pancreatic cancer:Exploring the two-way traffic

Pancreatic cancer(PC)is often associated with a poor prognosis.Long-standing diabetes mellitus is considered as an important risk factor for its development.This risk can be modified by the use of certain antidiabetic medications.On the other hand,new-onset diabetes can signal towards an underlying PC in the elderly population.Recently,several attempts have been made to develop an effective clinical tool for PC screening using a combination of history of new-onset diabetes and several other clinical and biochemical markers.On the contrary,diabetes affects the survival after treatment for PC.We describe this intimate and complex two-way relationship of diabetes and PC in this review by exploring the underlying pathogenesis.

Pathological abnormalities in splenic vasculature in non-cirrhotic portal hypertension:Its relevance in the management of portal hypertension

BACKGROUND Portal hypertension(PH)is associated with changes in vascular structure and function of the portosplenomesenteric system(PSMS).This is referred to as portal hypertensive vasculopathy.Pathological abnormalities of PSMS has been described in the literature for cirrhotic patients.Raised portal pressure and hyperdynamic circulation are thought to be the underlying cause of this vasculopathy.In view of this,it is expected that pathological changes in splenic and portal vein similar to those reported in cirrhotic patients with PH may also be present in patients with non-cirrhotic PH(NCPH).AIM To investigate pathological abnormalities of splenic vein in patients with NCPH,and suggest its possible implications in the management of PH.METHODS A prospective observational study was performed on 116 patients with NCPH[Extrahepatic portal vein obstruction(EHPVO):53 and non-cirrhotic portal fibrosis(NCPF):63]who underwent proximal splenorenal shunt(PSRS),interposition shunt or splenectomy with devascularization in JIPMER,Pondicherry,India,a tertiary level referral center,between 2011-2016.All patients were evaluated by Doppler study of PSMS,computed tomography portovenogram and upper gastrointestinal endoscopy.An acoustic resonance forced impulse(ARFI)scan and abdomen ultrasound were done for all cases to exclude cirrhosis.Intraoperative and histopathological assessment of the harvested splenic vein was performed in all.The study group was divided into delayed and early presentation based on the median duration of symptoms(i.e.108 mo).RESULTS The study group comprising of 116 patients[77(66%)females and 39(34%)males]with NCPH had a median age of 22 years.Median duration of symptoms was 108 mo.The most common presentation in both EHPVO and NCPF patients was upper gastrointestinal bleeding(hematemesis and melena).The ARFI scan revealed a median score of 1.2(1.0-1.8)m/s for EHPVO and 1.5(0.9-2.8)m/s for NCPF.PSRS was performed in 84 patients(two of whom underwent interposition PSRS using a 10 mm Dacron graft);splenoadrenal shunt in 9;interposition mesocaval shunt in 5;interposition 1st jejunal to caval shunt in 1 patient and devascularization with splenectomy in 17 patients.Median presplenectomy portal pressure was 25(range:15-51)mm Hg.In 77%cases,the splenic vein was abnormal upon intraoperative assessment.Under macroscopic examination,wall thickening was observed in 108(93%),venous thrombosis in 32(28%)and vein wall calcification in 27(23%)cases.Upon examination under a surgical magnification loupe,21(18%)patients had intimal defects in the splenic vein.Histopathological examination of veins was abnormal in all cases.Medial hypertrophy was noted in nearly all patients(107/116),while intimal fibrosis was seen in 30%.Ninety one percent of patients with intimal fibrosis also had venous thrombosis.Vein wall calcification was found in 22%,all of whom had intimal fibrosis and venous thrombosis.The proportion of patients with pathological abnormalities in the splenic vein were significantly greater in the delayed presentation group as compared to the early presentation group.CONCLUSION Pathological changes in the splenic vein similar to those in cirrhotic patients with PH are noted in NCPH.We recommend that PH in NCPH be treated as systemic and pulmonary hypertension equivalent in the gastrointestinal tract,and that early aggressive therapy be initiated to reduce portal pressure and hemodynamic stress to avoid potential lethal effects.

Incretin based therapy and pancreatic cancer:Realising the reality

Incretin-based therapies like glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors help maintain the glycaemic control in patients with type 2 diabetes mellitus with additional systemic benefits and little risk of hypoglycaemia.These medications are associated with low-grade chronic pancreatitis in animal models inconsistently.The incidence of acute pancreatitis was also reported in some human studies.This inflammation provides fertile ground for developing pancreatic carcinoma(PC).Although the data from clinical trials and population-based studies have established safety regarding PC,the pathophysiological possibility that low-grade chronic pancreatitis leads to PC remains.We review the existing literature and describe the relationship between incretin-based therapies and PC.

Modified binding pancreaticogastrostomy vs modified Blumgart pancreaticojejunostomy after laparoscopic pancreaticoduodenectomy for pancreatic or periampullary tumors

BACKGROUND Laparoscopic pancreaticoenteric anastomosis is one of the technically challenging steps of minimally invasive pancreaticoduodenectomy(PD),especially during the learning curve.Despite multiple randomized controlled trials and meta-analyses,the type of pancreatico-enteric anastomosis as a risk factor for post-pancreatectomy complications is debatable.Also,the ideal technique of pancreatic reconstruction during the learning curve of laparoscopic PD has not been well studied.AIM To compare the short-term outcomes of modified binding pancreaticogastrostomy(PG)and Blumgart pancreaticojejunostomy(PJ)during learning curve of laparoscopic PD.METHODS The first 25 patients with resectable pancreatic or periampullary tumors who underwent laparoscopic PD with modified binding PG or modified Blumgart PJ between January 2015 and May 2020 were retrospectively analyzed to compare perioperative outcomes during the same learning curve.A single layer of the fullthickness purse-string suture was placed around the posterior gastrotomy in the modified binding PG.In the modified Blumgart technique,only a single transpancreatic horizontal mattress suture was placed on either side of the pancreatic duct(total two sutures)to secure the pancreatic parenchyma to the jejunum.Also,on the ventral surface,the knot is tied on the jejunal wall without going through the pancreatic parenchyma.Post pancreatectomy complications are graded as per the RESULTS During the study period,modified binding PG was performed in 27 patients and modified Blumgart PJ in 29 patients.The demographic and clinical parameters of the first 25 patients included in both groups were comparable.Lower end cholangiocarcinoma and ampullary adenocarcinoma were the primary indications for laparoscopic PD in both groups(32/50,64%).The median operative time for pancreatic reconstruction was significantly lower in the binding PG group(42 vs 58 min,P=0.01).The clinically relevant(Grade B/C)postoperative pancreatic fistula(POPF)was significantly more in the modified PJ group(28%vs 4%,P=0.04).In contrast,intraluminal postpancreatectomy hemorrhage(PPH)was more in the binding PG group(32%vs 4%,P=0.02).There was no significant difference in the incidence of delayed gastric emptying between the two groups.CONCLUSION During the learning curve of laparoscopic PD,modified binding PG reduces POPF but is associated with increased intraluminal PPH compared to PJ using the modified Blumgart technique.

Impact of surgery for chronic pancreatitis on the risk of pancreatic cancer:Untying the Gordian knot

Pancreatic ductal adenocarcinoma is an aggressive tumor with poor long-term outcomes.Chronic pancreatitis(CP)is considered a risk factor for the development of pancreatic cancer(PC).Persistent pancreatic inflammation and activation of pancreatic stellate cells play a crucial role in the pathogenesis of CPrelated PC by activating the oncogene pathway.While genetic mutations increase the possibility of recurrent and persistent pancreatic inflammation,they are not directly associated with the development of PC.Recent studies suggest that early surgical intervention for CP might have a protective role in the development of CP-related PC.Hence,the physician faces the clinical question of whether early surgical intervention should be recommended in patients with CP to prevent the development of PC.However,the varying relative risk of PC in different subsets of CP underlines the complex gene-environment interactions in the disease pathogenesis.Hence,it is essential to stratify the risk of PC in each individual patient.This review focuses on the complex relationship between CP and PC and the impact of surgical intervention on PC risk.The proposed risk stratification based on the genetic and environmental factors could guide future research and select patients for prophylactic surgery.

Do preoperative pancreatic computed tomography attenuation index and enhancement ratio predict pancreatic fistula after pancreaticoduodenectomy?

BACKGROUND The commonly used predictors of clinically relevant postoperative pancreatic fistula(CR-POPF)following pancreaticoduodenectomy(PD)have subjective assessment components and can be used only in the postoperative setting.Also,the available objective predictors based on preoperative cross-sectional imaging were not prospectively studied.AIM To evaluate the accuracy of the pancreatic attenuation index(PAI)and pancreatic enhancement ratio(PER)for predicting CR-POPF following PD and its correlation with pancreatic fat fraction and fibrosis.METHODS A prospective observational study included patients who underwent PD for benign and malignant pathology of the periampullary region or pancreatic head between February 2019 and February 2021.Patients undergoing extended or total pancreatectomy and those with severe atrophy of pancreatic tissue or extensive parenchymal calcifications in the pancreatic head and neck precluding calculation of PAI and PER were excluded from the study.Preoperatively PAI was measured in the neck of the pancreas by marking regions of interest(ROI)in the non-contrast computed tomography(CT),and PER was measured during the contrast phase of the CT abdomen.Also,the fibrosis score and fat fraction of the pancreatic neck were assessed during the histopathological examination.Demographic,clinical and preoperative radiological indices(PAI,PER)were evaluated to predict CR-POPF.Preoperative pancreatic neck CT indices were correlated with the histopathological assessment of fat fraction and fibrosis.RESULTS Of the 70 patients who underwent PD,61 patients fulfilling the inclusion criteria were included in the analysis.The incidence of CR-POPF was 29.5%(18/61).PAI had no association with the development of CR-POPF.Of the preoperative parameters,PER(mean±standard deviation[SD])was significantly lower in patients developing CR-POPF(0.58±0.20 vs 0.81±0.44,P=0.006).The area under the curve for the PER was 0.661(95%CI:0.517-0.804),which was significant(P=0.049).PER cut-off of 0.673 predicts CR-POPF with 77.8%sensitivity and 55.8%specificity.PAI and PER had a weak negative correlation(Strength-0.26,P=0.037).Also,PER showed a moderately positive correlation with fibrosis(Strength 0.50,P<0.001).Patients with CR-POPF had a significantly higher incidence of the intraabdominal abscess(50%vs 2.3%,P<0.001),delayed gastric emptying(83.3%vs 30.2,P<0.001),and prolonged mean(±SD)postoperative hospital stay(26.8±13.9 vs 9.6±3.6,P=0.001).CONCLUSION PER exhibited good accuracy in predicting the development of CR-POPF.PER additionally showed a good correlation with PAI and fibrosis scores and may be used as an objective preoperative surrogate for assessing pancreatic texture.However,ROI-based PAI did not show any association with CR-POPF and pancreatic fat fraction.