Grigoriy Bolshakov

Dr. Grigoriy Bolshakov

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 June 2024 in Cancers
Verified
Journal Article
Open access
PDF file
VEViacheslav Egorov
Viacheslav Egorov
PKPavel Kim
Pavel Kim
SDSoslan Dzigasov
Soslan Dzigasov
EKEugeny Kondratiev
Eugeny Kondratiev
ASAlexander Sorokin
Alexander Sorokin
TDTatiana Dakhtler
Tatiana Dakhtler
The “vein definition” for locally advanced pancreatic ductal adenocarcinoma (LA PDAC) assumes portal-to-superior mesenteric vein (PV/SMV) unreconstructability due to tumor involvement or occlusion. Radical pancreatectomies with SMV resection without PV/SMV reconstruction are scarcely discussed in the literature. Retrospective analysis of 19 radical pancreatectomies for “low” LA PDAC with SMV and all its tributaries resection without PV/SMV reconstruction has shown zero mortality; overall morbidity—56%; Dindo–Clavien—3–10.5%; R0—rate—82%; mean operative procedure time—355 ± 154 min; mean blood loss—330 ± 170 mL; delayed gastric emptying—25%; and clinically relevant postoperative pancreatic fistula—8%. In three cases, surgery was associated with superior mesenteric (n2) and common hepatic artery (n1) resection. Surgery was completed without vein reconstruction (n13) and with inferior mesenteric-to-splenic anastomosis (n6). There were no cases of liver, gastric, or intestinal ischemia. A specific complication of the SMV resection without reconstruction was 2–3 days-long intestinal edema (48%). Median overall survival was 25 months, and median progression-free survival was 18 months. All the relapses, except two, were distant. The possibility of successful SMV resection without PV/SMV reconstruction can be predicted before surgery by CT-based reconstructions. The mandatory anatomical conditions for the procedure were as follows: (1) preserved SMV-SV confluence; (2) occluded SMV for any reason (tumor or thrombus); (3) well-developed inferior mesenteric vein collaterals with dilated intestinal veins; (4) no right-sided vein collaterals; and (5) no varices in the upper abdomen. Conclusion: “Low” LA PDACs involving SMV with all its tributaries can be radically and safely resected in highly and specifically selected cases without PV/SMV reconstruction with an acceptable survival rate.

21 May 2026 in Cancers
Verified
Journal Article
Open access
PDF file
VEViacheslav Egorov
Viacheslav Egorov
SDSoslan Dzigasov
Soslan Dzigasov
AKAlexey Kolygin
Alexey Kolygin
MVMikhail Vyborniy
Mikhail Vyborniy
GBGrigoriy Bolshakov
Grigoriy Bolshakov
ASAlexander Sorokin
Alexander Sorokin
Background: Spleen-preserving (SP) distal pancreatectomy (DP) with splenic vessels resection (SVR) (Warsaw procedure, WP) is an option for the treatment of tumors with low malignant potential. The reverse blood flow through the short gastric arteries (SGA) explains the preservation of the spleen after SVR, but leaves the source of the blood supply to the SGAs hidden. The types of blood supply to the spleen after WP and their incidence have not been previously described, nor has the significance of these types for locally advanced pancreatic head cancer (LAPHC) surgery been determined. Aim: To determine the main types of spleen blood supply after WP, and to assess the feasibility and safety of splenic artery (SA) rotation for the organ-preserving surgery of LAPHC. Methods: Retrospective analyses of demographic and perioperative data, including CT scans, overall (OS) and progression-free (PFS) survival after 71 SP DP SVR and 41 SP SVR pancreaticoduodenectomies (PD) and total pancreatectomies (TP) for LAPHC (2007–2025). Results: In 134 SP procedures, SA was resected in 115 cases (71DP, 9 TP, 3 central, and 32 PD). Indications for surgery were MCN (41), IPMN (14), CSA (3), NEN (25), SPPN (8), PHDAC (40), sarcoma (1), autoimmune (1), and calculous chronic pancreatitis (1). There were no deaths or ischemia-related splenectomies. Morbidity—31% (n23); Dindo–Clavien (D-C) > 3b-2.8%; POPF-grade B-n7 (10.6%); splenic infarctions on CT after SVR-n18 (23%), one symptomatic. CT revealed three types of arterial blood supply to the spleen after SPDP SVR: left gastric artery (LGA) type (n50, 70, 5%), gastro-epyploic arcade (GEA) type (n9, 12, 5%), and an intermediate type (n12, 17%). Spleen- and pancreas tail-preserving SVR pancreatectomies for LAPHC (n41) were accompanied by rotation of the SA to substitute resected SMA (n19) and CHA (n15) for 26 Whipples and 8TPs. There were no ischemic complications. D-C > 3–19.5%. Median OS and PFS for PDAC were 35 and 21 months for 29.5 months median follow-up. Conclusions: Despite the preservation of blood flow through all potential sources of splenic blood supply following resection of the splenic artery, the main collaterals supplying the spleen after WP are LGA branches (~90%). This knowledge, with strict adherence to the developed criteria, allows for the safe preservation of the spleen, pancreatic tail, and stomach during pancreatectomies with SA resection, including its rotation for the substitution of the SMA and CHA in LAPHC.

20 May 2024 in Preprints.org
Verified
Preprint
Open access
PDF file
VEViacheslav Egorov
Viacheslav Egorov
PKPavel Kim
Pavel Kim
SDSoslan Dzigasov
Soslan Dzigasov
EKEugeny Kondratiev
Eugeny Kondratiev
ASAlexander Sorokin
Alexander Sorokin
TDTatiana Dakhtler
Tatiana Dakhtler
Introduction. “Vein definition” for locally advanced pancreatic ductal adenocarcinoma (LA PDAC) assumes portal-to-superior mesenteric vein (PV/SMV) unreconstructability due to tumor involvement or occlusion. Radical pancreatectomies with SMV resection without PV/SMV reconstruction are scarcely discussed in the literature. Retrospective analysis of 19 radical pancreatectomies for “low” LA PDAC with SMV and all its tributaries resection without PV/SMV reconstruction has shown zero mortality, overall morbidity – 56%, Dindo-Clavien – 3-10,5%, R0- rate – 82%, mean operative procedure time – 355±154 min, mean blood loss – 330±170 ml, delayed gastric emptying– 25%, clinically relevant postoperative pancreatic fistula – 8%. In three cases surgery was associated with superior mesenteric (n2) and common hepatic artery (n1) resection. Surgery was completed without vein reconstruction (n13) and with inferior mesenteric-to-splenic anastomosis (n6). There were no cases of liver, gastric, or intestinal ischemia. A specific complication of the SMV resection without reconstruction was 2-3 days-long intestinal edema (48%). Median overall survival – 25 months, median progression-free survival – 18 months. All the relapses, except two, were distant. The possibility of successful SMV resection without PV/SMV reconstruction can be predicted before surgery by CT-based reconstructions. The mandatory anatomical conditions for the procedure were: 1) preserved SMV-SV confluence; 2) occluded SMV for any reason (tumor or thrombus); 3) well-developed inferior mesenteric vein collaterals with dilated intestinal veins; 4) no right-sided vein collaterals, and 5) no varices in the upper abdomen. Conclusion: “Low” LA PDACs involving SMV with all its tributaries can be radically and safely resected in highly and specifically selected cases without PV/SMV reconstruction with an acceptable survival rate.

13 April 2026 in Preprints.org
Verified
Preprint
Open access
PDF file
VEViacheslav Egorov
Viacheslav Egorov
SDSoslan Dzigasov
Soslan Dzigasov
AKAlexey Kolygin
Alexey Kolygin
MVMikhail Vyborniy
Mikhail Vyborniy
GBGrigoriy Bolshakov
Grigoriy Bolshakov
ASAlexander Sorokin
Alexander Sorokin
Background. Spleen-preserving (SP) distal pancreatectomy (DP) with splenic vessels resection (SVR) (Warsaw procedure, WP) is an option for treatment of tumors with low-malignant potential. The reverse blood flow through the short gastric arteries (SGA) explains the preservation of the spleen after SVR, but leaves the source of blood supply to the SGAs hidden. The types of blood supply to the spleen after WP and their incidence have not been previously described, nor has the significance of these types for locally advanced pancreatic head cancers (LAPHC) surgery. Aim. To determine the main types of the spleen blood supply after WP, and to assess feasibility and safety of splenic artery (SA) rotation for the organ-preserving surgery of LAPHC. Methods. Retrospective analysis of demographic and perioperative data, including CT scans analysis, overall (OS) and progression-free (PFS) survival after 71 SP DP SVR and 41 SP SVR pancreaticoduodenectomies (PD) and total pancreatectomies (TP) for LAPHC (2007-2025). Results: In 134 SP procedures, SA was resected in 115 cases (71DP, 9 TP, 3 central, 32 PD). Indications for surgery were MCN (41), IPMN (14), CSA(3), NEN(25), SPPN(8), PHDAC(40), sarcoma(1), autoimmune(1), and calculous chronic pancreatitis(1). There were no deaths and ischemia-related splenectomies. Morbidity-31%(n23), Dindo-Clavien (D-C)> 3b-2,8%, POPF grade B-n7(10.6%), splenic infarctions on CT after SVR-n18(23%), with one symptomatic. CT revealed three types of arterial blood supply to the spleen after SPDPSVR: left gastric artery(LGA) type (n50,70,5%), gastro-epyploic arcade (GEA) type(n9,12,5%), and an intermediate type(n12,17%). Spleen- and pancreas tail-preserving SVR pancreatectomies for LAPHC (n41) were accompanied by rotation of the SA to substitute resected SMA(n19) and CHA(n15) for 26 Whipples and 8TPs. There were no ischemic complications. D-C >3-19.5%. Median OS and PFS for PDAC was 35 and 21 months for 29.5 months median follow-up. Conclusion. The main collaterals supplying the spleen after WP are LGA branches (~ 90%). This knowledge with strict adherence to the developed criteria safely preserves the spleen, pancreatic tail and stomach during pancreatectomies with SA resection, including its rotation for substitution of the SMA and CHA in LAPHC.