Friction Stir Processing of Stainless Steel for Ascertaining Its Superlative Performance in Bioimplant Applications

Substrate-cell interactions for a bioimplant are driven by substrate's surface characteristics. In addition, the performance of an implant and resistance to degradation are primarily governed by its surface properties. A bioimplant typically degrades by wear and corrosion in the physiological environment, resulting in metallosis. Surface engineering strategies for limiting degradation of implants and enhancing their performance may reduce or eliminate the need for implant removal surgeries and the associated cost. In the current study, we tailored the surface properties of stainless steel using submerged friction stir processing (FSP), a severe plastic deformation technique. FSP resulted in significant microstructural refinement from 22 μm grain size for the as-received alloy to 0.8 μm grain size for the processed sample with increase in hardness by nearly 1.5 times. The wear and corrosion behavior of the processed alloy was evaluated in simulated body fluid. The processed sample demonstrated remarkable improvement in both wear and corrosion resistance, which is explained by surface strengthening and formation of a highly stable passive layer. The methylthiazol tetrazolium assay demonstrated that the processed sample is better in supporting cell attachment, proliferation with minimal toxicity, and hemolysis. The athrombogenic characteristic of the as-received and processed samples was evaluated by fibrinogen adsorption and platelet adhesion via the enzyme-linked immunosorbent assay and lactate dehydrogenase assay, respectively. The processed sample showed less platelet and fibrinogen adhesion compared with the as-received alloy, signifying its high thromboresistance. The current study suggests friction stir processing to be a versatile toolbox for enhancing the performance and reliability of currently used bioimplant materials.

Synthesis, spectroscopic, dielectric, molecular docking and DFT studies of (3E)-3-(4-methylbenzylidene)-3,4-dihydro-2H-chromen-2-one: an anticancer agent

BACKGROUND

Coumarin (2H-chromen-2-one) and its derivatives have a wide range of biological and pharmaceutical activities. They possess antitumor, anti-HIV, anticoagulant, antimicrobial, antioxidant, and anti-inflammatory activities. Synthesis and isolation of coumarins from different species have attracted the attention of medicinal chemists. Herein, we report the synthesis, molecular structure, dielectric, anticancer activity and docking studies with the potential target protein tankyrase.

RESULTS

Molecular structure of (3E)-3-(4-methylbenzylidene)-3,4-dihydro-2H-chromen-2-one (MBDC) is derived from quantum chemical calculations and compared with the experimental results. Intramolecular interactions, stabilization energies, and charge delocalization are calculated by NBO analysis. NLO property and dielectric quantities have also been determined. It indicates the formation of a hydrogen bonding between -OH group of alcohol and C=O of coumarin. The relaxation time increases with the increase of bond length confirming the degree of cooperation and depends upon the shape and size of the molecules. The molecule under study has shown good anticancer activity against MCF-7 and HT-29 cell lines. Molecular docking studies indicate that the MBDC binds with protein.

CONCLUSIONS

In this study, the compound (3E)-3-(4-methylbenzylidene)-3,4-dihydro-2H-chromen-2-one was synthesized and characterized by spectroscopic studies. The computed and experimental results of NMR study are tabulated. The dielectric relaxation studies show the existence of molecular interactions between MBDC and alcohol. Theoretical results of MBDC molecules provide the way to predict various binding sites through molecular modeling and these results also support that the chromen substitution is more active in the entire molecule. Molecular docking study shows that MBDC binds well in the active site of tankyrase and interact with the amino acid residues. These results are compared with the anti cancer drug molecule warfarin derivative. The results suggest that both molecules have comparable interactions and better docking scores. The results of the antiproliferative activity of MBDC and Warfarin derivative against MCF-7 breast cancer and HT-29 colon cancer cell lines at different concentrations exhibited significant cytotoxicity. The estimated half maximal inhibitory concentration (IC 50) value for MBDC and Warfarin derivative was 15.6 and 31.2 μg/ml, respectively. This enhanced cytotoxicity of MBDC in MCF-7 breast cancer and HT-29 colon cancer cell lines may be due to their efficient targeted binding and eventual uptake by the cells. Hence the compound MBDC may be considered as a drug molecule for cancer.Graphical abstractThe binding mode of the ligand MBDC at active site of protein and the graphical representation of cell inhibition for MCF-7 and HT-29 cell lines.

On a stochastic differential equation modeling of prey-predator evolution

We study a stochastic differential equation model of prey-predator evolution. To keep in line with a known deterministic model we include the social and interaction terms with the drift in our model, and the randomness arises as fluctuations in the ecosystem. The notion of equilibrium population level and special types of fluctuations force us to work with degenerate elliptic operators. We consider the propagation of the population system in a sufficiently large but bounded domain. This enables us to look at not only the population extinction, but also the explosion beyond a certain level. Both extinction and explosion are possible; and, when they are not, we show that the population asymptotically reaches the equilibrium level. We show that the extinction, explosion and saturation probabilities satisfy, as functions of the initial population size, an integral equation arising out of a Dirichlet problem for a non-degenerate elliptic equation; and these probabilities are also smooth solutions of the Dirichlet problems. They are also used to express the solution of another Dirichlet problem for a degenerate elliptic equation.

Highly regio- and diastereo-selective synthesis of novel tri- and tetra-cyclic perhydroquinoline architectures via an intramolecular [3 + 2] cycloaddition reaction

A facile and efficient synthetic protocol was established for the construction of novel tri- and tetra-cyclic pyrrolo/pyrrolizinoquinoline architectures via the in situ formation of azomethine ylide followed by an intramolecular [3 + 2] cycloaddition reaction strategy. This protocol leads to the creation of two/three new rings and three/four contiguous stereocentres, in which one of them is a tetra-substituted carbon center, in a highly diastereoselective fashion with excellent yields.

Crystal structure of methyl 1-methyl-3,5-diphenyl-7-tosyl-3,6,7,11b-tetra-hydro-pyrazolo-[4',3':5,6]pyrano[3,4-c]quinoline-5a(5H)-carboxyl-ate

In the title compound, C35H31N3O5S, the piperidine ring adopts an envelope conformation, with the methine C atom as the flap, and the pyran ring adopts a sofa conformation. The mean planes of these two rings are almost normal to one another, making a dihedral angle of 85.96 (5)°. The two phenyl rings, one attached to the pyrazole ring and the other to the pyran ring, are inclined to one another by 65.41 (11)°. They are inclined to the mean planes of the rings to which they are attached by 12.59 (11) and 70.09 (9)°, respectively. There is an intra-molecular C-H⋯π inter-action involving the tosyl-ate methyl group and the phenyl ring attached to the pyrazole ring. In the crystal, mol-ecules are linked by C-H⋯π inter-actions, forming ribbons parallel to (10-2). The ribbons are linked by slipped parallel π-π inter-actions involving inversion-related pyrazole rings [inter-centroid distance = 3.672 (2) Å], forming slabs parallel to (001). A preliminary report of this structure has been published [Bakthadoss et al. (2014 ▶). Eur. J. Org. Chem. pp. 1505-1513].

Methyl 11,14,16-triphenyl-8,12-dioxa-14,15-di-aza-tetra-cyclo-[8.7.0.0(2,7).0(13,17)]hepta-deca-2(7),3,5,13(17),15-penta-ene-10-carboxyl-ate

In the title compound, C₃₃H₂₆N₂O₄, the pyrazole ring makes dihedral angles of 15.13 (7) and 60.80 (7)° with the adjacent phenyl rings. Both di­hydro­pyran rings exhibit half-chair conformations. A weak intra­molecular C—H⋯O inter­action occurs. In the crystal, mol­ecules are linked into inversion dimers through pairs of C—H⋯N inter­actions. Weak C—H⋯π inter­actions are also observed.

14-Methoxy-4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diazatetracyclo[8.8.0.02,7.013,18]octadeca-2(7),13,15,17-tetraene-3,5,11-trione

The title compound, C₂₃H₂₀N₂O₆, crystallizes with two mol­ecules in the asymmetric unit in which the dihedral angles between the mean planes of the pyran and phenyl rings are 66.6 (1) and 61.9 (1) °. The fused pyrone and pyran rings each adopts a sofa conformation. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules, forming a two-dimensional network parallel to [001].

14-Eth-oxy-4,6,9-trimethyl-8,12-dioxa-4,6-diaza-tetra-cyclo-[8.8.0.0(2,7).0(13,18)]octa-deca-2(7),13,15,17-tetra-ene-3,5,11-trione

In the title compound, C₁₉H₂₀N₂O₆, the pyrone and pyran rings adopt envelope conformations with the same common C atom as the flap, the dihedral angle between the planes of the remaining ring atoms being 68.27 (4)°. The planar atoms of the pyran ring and the diaza­cyclic ring are almost coplanar, the dihedral angle between their mean planes being 3.29 (7)°. Moreover, the planar atoms of the pyrone ring and benzene ring of the coumarin unit are also close to coplanar, the dihedral angle between their mean planes being 8.03 (9)°. The meth­oxy group lies in the plane of the benzene ring, with a dihedral angle between their mean planes of 9.4 (2)°. In the crystal, the molecules are linked by C—H⋯O hydrogen bonds resulting in sheets of mol­ecules in the ac plane.

14-Eth-oxy-4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diaza-tetra-cyclo-[8.8.0.0(2,7).0(13,18)]octa-deca-2(7),13,15,17-tetra-ene-3,5,11-trione

In the title compound, C₂₃H₂₀N₂O₆, the fused pyrone and pyran rings each adopt a sofa conformation. The dihedral angle between the mean planes of the pyran and phenyl rings is 61.9 (1)°. In the crystal, mol­ecules are linked by two pairs of C—H⋯O hydrogen bonds, forming dimers. These dimers are linked via a third C—H⋯O hydrogen bond, forming a two-dimensional network parallel to (10-2).

(E)-Methyl 2-[(1,3-dioxoisoindolin-2-yl)methyl]-3-phenylacrylate

In the title compound, C₁₉H₁₅NO₄, the isoindole ring system is essentially planar [maximum deviation = 0.011 (1) Å] and is oriented at a dihedral angle of 75.7 (1)° with respect to the phenyl ring. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond. The crystal packing is stabilized by C—H⋯O hydrogen bonds, which generate zigzag chains along the a axis. The crystal packing is further stabilized by a C—H⋯π inter­action.

2-Formyl-6-meth-oxy-phenyl cinnamate

In the title compound, C(17)H(14)O(4), the C=C bond adopts an E conformation and the dihedral angle between the benzene rings is 73.9 (1)°. The crystal packing features C-H⋯O hydrogen bonds, which generate C(4) chains propagating along the b-axis direction. Weak aromatic π-π stacking inter-actions [centroid-centroid distance = 3.703 (1) Å] are also observed.

Methyl (2E)-2-({2-[(2E)-2-benzylidene-3-methoxy-3-oxopropyl]-1,3-dioxoindan-2-yl}methyl)-3-phenylprop-2-enoate

In the title compound, C₃₁H₂₆O₆, the five-membered ring of the indane unit adopts a slight envelope conformation with the flap atom displaced by 1.38 (14) Å. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond, which generates an S(9) ring motif. In the crystal, pairs of C—H⋯O hydrogen bonds link centrosymmetrically related mol­ecules into dimers, generating R₂²(22) ring motifs. The crystal packing is further stabilized by C—H⋯π inter­actions.

(E)-Methyl 3-(3,4-dimeth-oxy-phen-yl)-2-[(1,3-dioxoisoindolin-2-yl)meth-yl]acrylate

In the title compound, C(21)H(19)NO(6), the isoindole ring system is essentially planar [maximum deviation = 0.019 (2) Å for the N atom] and is oriented at a dihedral angle of 51.3 (1)° with respect to the benzene ring. The two meth-oxy groups are almost coplanar with the attached benzene ring [C-O-C-C = 3.7 (4) and 4.3 (4)°]. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯O hydrogen bond, which generates an S(9) ring motif. In the crystal, mol-ecules are linked through bifurcated C-H⋯(O,O) hydrogen bonds having R(1) (2)(5) ring motifs, forming chains along the b-axis direction. The crystal packing is further stabilzed by π-π inter-actions [centriod-centroid distance = 3.463 (1) Å].

(E)-3-(2-Chlorophenyl)-2-[(2-formylphenoxy)methyl]prop-2-enenitrile

In the title compound, C17H12ClNO2, the dihedral angle between the two benzene rings is 42.9 (1)°. There are no sgnificant intermolecular interactions.

(2Z)-2-{[N-(2-Formylphenyl)-4-methylbenzenesulfonamido]methyl}-3-(4-methylphenyl)prop-2-enenitrile

In the title compound, C₂₅H₂₂N₂O₃S, the sulfonyl-bound benzene ring forms dihedral angles of 36.8 (2) and 81.4 (2)°, respectively, with the formyl­benzene and methyl­benzene rings. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond, which generates an S(5) ring motif. The crystal packing is stabilized by C—H⋯O hydrogen bonds, which generate C(11) chains along the b axis. The crystal packing is further stabilized by π–π inter­actions [centroid–centroid distance = 3.927 (2) Å].

N-(2-Formyl-phen-yl)-4-toluene-sulfonamide: a second monoclinic polymorph

The title compound, C₁₄H₁₃NO₃S, (I), is a second monoclinic polymorph. The original polymorph, (II), was reported by Mahía et al. [Acta Cryst. (1999), C55, 2158–2160]. Polymorph (II) crystalllized in the space group P2₁/c (Z = 4), whereas the title polymorph (I) occurs in the space group P2₁/n (Z = 4). The dihedral angle between the two aromatic rings is 75.9 (1)° in (I) compared to 81.9 (1)° for (II). In both polymorphs, two S(6) rings are generated by intra­molecular N—H⋯O and C—H⋯O hydrogen bonds, resulting in similar mol­ecular geometries. However, the two polymorphs differ concerning their crystal packing. In (I), mol­ecules are linked into C(8) zigzag chains along the b axis by C—H⋯O hydrogen bonds, whereas in (II) mol­ecules are linked by C—H⋯O hydrogen bonds, forming C(7) chains along the b axis. The title polymorph is further stabilized by inter­molecular C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.814 (1) Å]. These inter­actions are not evident in polymorph (II).

(E)-6-Methyl-3-(2-methyl-benzyl-idene)-chroman-2-one

In the title compound, C₁₈H₁₆O₂, the heterocyclic ring of the chroman-2-one system adopts a slightly distorted screw-boat conformation. The dihedral angle between the least-squares planes of the coumarin ring system and the benzene ring is 67.5 (1)°. The crystal packing features C—H⋯O hydrogen bonds, which link the mol­ecules into centrosymmetric R₂²(8) dimers, and C—H⋯π inter­actions.

Methyl (Z)-2-[(4-bromo-2-formyl-phen-oxy)meth-yl]-3-(4-methyl-phen-yl)acrylate

In the title compound, C(19)H(17)BrO(4), the dihedral angle between the two benzene rings is 82.9 (2)°. The mol-ecular structure is stabilized by an intra-molecular C-H⋯O hydrogen bond, which generates an S(7) ring motif. The crystal packing is stabilized by C-H⋯O hydrogen bonds, which generate two centrosymmetic ring systems with R(2) (2)(18) and R(2) (2)(14) graph-set motifs. The crystal packing is further stabilized by inter-molecular π-π inter-actions [centroid-centroid distance = 3.984 (2) Å].

Methyl (2E)-2-[(2,4-dioxo-1,3-thiazolidin-3-yl)methyl]-3-phenylprop-2-enoate

In the title compound, C₁₄H₁₃NO₄S, the thia­zolidine ring is essentially planar [maximum deviation = 0.010 (2) Å for the carbonyl C atom between the N and S atoms] and is oriented at a dihedral angle of 60.1 (1)° with respect to the benzene ring. In the crystal, mol­ecules are linked into zigzag chains running along the c axis by C—H⋯O hydrogen bonds. The crystal packing is further stabilized by C—H⋯π inter­actions involving the benzene ring.

Methyl (2Z)-2-({N-[2-(hydroxymethyl)phenyl]-4-methylbenzenesulfonamido}methyl)-3-phenylprop-2-enoate

In the title compound, C₂₅H₂₅NO₅S, the O atom of the hy­droxy group is disordered over two positions, with occupancies of 0.820 (2) and 0.180 (2). The sulfonyl-bound benzene ring forms dihedral angles of 31.8 (1) and 60.7 (1)°, respectively, with the hy­droxy­methyl­benzene and phenyl rings. The mol­ecular conformation is stabilized by an intra­molecular O—H⋯O hydrogen bond, generating an S(8) ring motif. The crystal packing is stabilized by inter­molecular C—H⋯O hydrogen bonds and C—H⋯π inter­actions.

Methyl (2Z)-2-{[N-(2-formyl-phen-yl)-4-methyl-benzene-sulfonamido]-meth-yl}-3-(naphthalen-1-yl)prop-2-enoate

In the title compound, C(29)H(25)NO(5)S, the sulfonyl-bound benzene ring forms dihedral angles of 42.1 (1) and 48.5 (1)°, respectively, with the formyl-substituted benzene ring and the naphthalene residue. In the crystal, pairs of C-H⋯O inter-actions lead to the formation of R(2) (2)(10) inversion dimers, which are linked by further C-H⋯O inter-actions into supra-molecular tapes running along [100]. The crystal packing is further stabilized by C-H⋯π inter-actions.

1'-Methyl-4'-(4-methyl-phen-yl)dispiro-[1-benzopyran-3(4H),3'-pyrrolidine-2',3''-indoline]-2,2''-dione

In the title compound, C₂₇H₂₄N₂O₃, the pyrroldine ring adopts a twist conformation, while the six-membered pyran­one ring of the coumarin ring system is in a sofa conformation. In the crystal, pairs of N—H⋯O hydrogen bonds link the mol­ecules into inversion R₂²(8) dimers. These dimers are further connected via C—H⋯O hydrogen bonds.

Methyl (Z)-2-[(2,4-dioxothiazolidin-3-yl)methyl]-3-(2-methylphenyl)prop-2-enoate

The C=C bond in the title compound, C₁₅H₁₅NO₄S, has a Z configuration. The thia­zolidine ring is essentially planar [maximum deviation = 0.008 (1) Å for the N atom] and is oriented at a dihedral angle of 59.1 (1)° with respect to the benzene ring. In the crystal, pairs of C—H⋯O hydrogen bonds link centrosymmetrically related mol­ecules into dimers, generating R₂²(18) ring motifs. The crystal packing is further stabilized by C—H⋯π and C—O⋯π [O⋯centroid = 3.412 (2) Å and C—O⋯centroid = 115.0 (1)°] inter­actions.

(E)-2-[(2-Formylphenoxy)methyl]-3-(4-methylphenyl)prop-2-enenitrile

In the title compound, C₁₈H₁₅NO₂, the dihedral angle between the two benzene rings is 74.8 (1)°. The carbonitrile chain is almost linear, the C—C—N angle being 176.2 (2)°. In the crystal, π–π inter­actions [centroid–centroid distance = 3.842 (1) Å] are observed.

(Z)-3-(4-Chlorophenyl)-2-{[N-(2-formylphenyl)-4-methylbenzenesulfonamido]methyl}prop-2-enenitrile

In the title compound, C₂₄H₁₉ClN₂O₃S, the sulfonyl-bound benzene ring forms dihedral angles of 38.1 (2) and 81.2 (1)°, respectively, with the formyl benzene and benzene rings. The mol­ecular conformation is stabilized by a weak intra­molecular C—H⋯O hydrogen bond, which generates an S(5) ring motif. The crystal packing is stabilized by C—H⋯O hydrogen bonds, which generate C(7) zigzag chains along [010] and R₃³(19) ring motifs along [010]. The crystal packing is further stabilized by C—Cl⋯π inter­actions [Cl⋯centroid = 3.456 (2) Å and C—Cl⋯centroid = 173.4 (2)°].

1',6-Dimethyl-4'-phenyl-dispiro-[1-benzopyran-3(4H),3'-pyrrolidine-2',3''-indoline]-2,2''-dione

In the title compound, C₂₇H₂₄N₂O₃, the five-membered pyrroldine ring adopts an envelope conformation (with the N atom in the flap position) and the six-membered pyran­one ring of the coumarine ring system adopts a slightly distorted boat conformation. The oxindole unit makes dihedral angles of 89.7 (1) and 25.6 (1)°, respectively, with the pyrrolidine ring and the coumarin ring system. The mol­ecular structure is stabilized by two intra­molecular C—H⋯O contacts and two intra­molecular π–π inter­actions [centroid–centroid seperations of 3.514 (1) and 3.623 (1) Å]. The crystal packing features N—H⋯O hydrogen bonds, which link the mol­ecules into cyclic centrosymmetric R₂²(8) dimers, and C—H⋯π inter­actions.

Methyl (Z)-2-{[N-(2-formyl-phen-yl)-4-methyl-benzene-sulfonamido]-meth-yl}-3-phenyl-prop-2-enoate

In the title compound, C₂₅H₂₃NO₅S, the sulfonyl-bound benzene ring forms dihedral angles of 37.2 (1) and 67.0 (1)°, respectively, with the formyl­phenyl and phenyl rings. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯π inter­action. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming a two-dimensional network in the (110) plane in which R₄⁴(38) ring motifs are generated.

Magnetic and dielectric properties study of cobalt ferrite nanoparticles synthesized by co-precipitation method

Cobalt ferrite nanoparticles were prepared by co-precipitation method and were heat treated at 100 oC, 200 oC, 400 oC and 600 oC for 2 h to increase the particle size. Phase purity of samples was confirmed by X-ray diffraction. Scherrer formula calculations showed crystallite size varied from 12 to 24 nm when heated from 100 oC to 600 oC. Transmission electron microscopy reveals a uniform and narrow particle size distribution about 12 nm for as-prepared cobalt ferrite particles. Room temperature saturation magnetization was found to vary from 40.8 to 67.0 emu/g as the particle size increased from12 nm to 24 nm. Increase in saturation magnetization with increase in particle size was attributed to the presence of magnetic inert layer on the surface of nanoparticles. Inert layer thickness calculated at 10 K and 300 K was 6 Å and 11 Å respectively. The dielectric properties ε’, tanδ, Z and θ have been studied as a function of frequency and particles size. For the 12 nm grain size, the dielectric constant is one order higher than that of bulk cobalt ferrite. Increase in the grain size showed an increase in the dielectric constant. The increase in the conductivity with grain size is mainly due to the grain size effects. The present study shows that the dielectric properties can be tailor-made to suit the requirement of a particular application by controlling the grain size.

Role of retrograde dilatation in the management of pharyngo-esophageal corrosive strictures

Pharyngo-esophageal corrosive stricture is a complex clinical scenario. If an esophageal opening cannot be found orally through endoscopy, a retrograde approach with a mini-laparotomy and gastrostomy should be attempted. This study primarily aimed at defining the role of preoperative retrograde dilatation of pharyngo-esophageal corrosive strictures. A retrospective analysis of 51 cases of pharyngo-esophageal corrosive strictures identified between 1997-2005 was performed. The demographic details were analyzed. The details of the injury to the pharynx either in isolation or in combination were noted and the management details were recorded. In 21 patients preoperative retrograde dilatation was considered and the technique was successful in 14 (Group I). In seven the technique failed (Group II) and these patients underwent transhiatal resection and gastric pull-through and/or retrosternal pharyngocoloplasty. In Group I patients the postoperative stay was significantly less than in Group II (12 +/- 2.03 days vs. 18 +/- 4.32 days; p = 0.001) Recurrent aspiration, respiratory tract infections, choking sensation and the need for tracheostomy were less frequent in Group I. The overall functional assessment was good in Group I. For treatment of pharyngo-esophageal obstruction, if antegrade dilatation is not possible due to technical reasons, retrograde dilatation is a viable option before opting for organ replacement/bypass procedures. There is no best replacement of the native organ to maintain quality of life.

Transabdominal modified devascularization procedure with or without esophageal stapler transection--an operation adequate for effective control of a variceal bleed. Is esophageal stapler transection necessary?

BACKGROUND

In Japan, the original Sugiura procedure reported favorable results in non-cirrhotic patients but in the West, the modified Sugiura procedure is not widely accepted because of high rebleeding, morbidity, and mortality in cirrhotics. We retrospectively analyzed the efficacy of our modified Sugiura procedure i.e., devascularization with/without esophageal transection combined with salvage endotherapy and pharmacotherapy for control of a variceal bleed.

MATERIALS AND METHODS

Between January 1999 and December 2004, 912 patients with variceal bleeding were treated. Of these, 66 (7.2%) patients were subjected to surgery after failed endotherapy/propranolol. Among these 66 patients, 52 had transabdominal devascularization (16 emergency, 36 elective); 14 patients underwent devascularization with esophageal stapler transection (group I), and 38 patients had devascularization without esophageal stapler transection (group II). Another 14 patients underwent elective end-to-side proximal splenorenal shunt surgery.

RESULTS

Postoperative mortality was 7.1% in group I, 10.5% in group II (P>0.05). Mortality for emergency surgery was 31.2% (5/16) but there were no deaths in the elective surgery group. Overall morbidity was 57.1% in group I and 21.0% in group II (P<0.05). The rates of variceal rebleeding were 7.1% and 7.8%; residual varices were 30.7% and 32.3%; recurrent varices were 7.6% and 5.8% following the group I and group II procedures, respectively, over a mean follow-up period of 39.9 (7-2) months. Esophageal transection-related morbidity (leak, stricture, and bleeding) was 21.4% (3/14) in group I.

CONCLUSIONS

Devascularization without esophageal stapler transection is a safe and effective procedure for adequate (urgent and long-term) control of variceal bleeding with similar results and less morbidity when compared to devascularization with esophageal transection in cirrhotic patients, as well as non-cirrhotic patients.