a prospective case series of 10 patients was conducted by the national university hospital , diabetic foot team , in singapore .
the study population was made up of six males and four females with a mean age of 54 ( range : 3766 years ) . in this study ,
the indications for usage of renasys go included ray ( toe and metatarsal ) amputation wounds , post - drainage wounds of abscess and post - debridement wounds for necrotizing fasciitis and ulcers of the heel , dorsum of foot and of the sole .
four ulcers were ray amputation wounds , two were wounds post - drainage of abscess , one was on the dorsum of the foot , one was on the left shin , one was on the left foot and one was on the right calf .
each ulcer was classified as either a grade 2 ulcer or a grade 3 ulcer , according to wagner 's classification ( 10 ) .
documentation in the study protocol included the patient 's demographics , diabetic history , presence of complications and infection markers .
all wounds were monitored and photographed as they progressed and wound dimensions were measured with a ruler ( fig .
the location and diagnosis of the ulcer was recorded as well as the presence of any granulation tissue .
clinical investigations performed prior to therapy included markers of infection ( leukocyte count , c - reactive protein and erythrocyte sedimentation rate ) .
a swab from the wound was sent for culture and sensitivity tests before application of the npwt system .
the npwt settings , mode of application , date of initiation and end of npwt , number and date of npwt dressing changes were recorded .
prior to renasys - go npwt treatment , adequate surgical debridement was performed on all wounds to remove any necrotic and infected tissue .
the npwt dressing was cut to fit the size and shape of the wound and the number of pieces used recorded to ensure all pieces were removed at each dressing change .
the wounds were sealed using semi - permeable film drape and a hole was cut in the center of the film .
the soft port was placed directly over the hole in the film and its tubing was connected to the canister tubing .
for all patients , the npwt device was set at continuous or mode with negative pressure of 100 or 120 mmhg .
the pressure settings were dependent on the amount of exudate from the wound and patient 's skin sensitivity since pressures may need to be lower to reduce pain on the skin .
npwt dressing changes were performed every 4872 hours by a trained medical officer or nurse . the number of npwt dressing changes ranged from two to nine dressings , while the duration of npwt treatment was 726 days .
in this study , the indications for usage of renasys go included ray ( toe and metatarsal ) amputation wounds , post - drainage wounds of abscess and post - debridement wounds for necrotizing fasciitis and ulcers of the heel , dorsum of foot and of the sole .
four ulcers were ray amputation wounds , two were wounds post - drainage of abscess , one was on the dorsum of the foot , one was on the left shin , one was on the left foot and one was on the right calf .
each ulcer was classified as either a grade 2 ulcer or a grade 3 ulcer , according to wagner 's classification ( 10 ) .
documentation in the study protocol included the patient 's demographics , diabetic history , presence of complications and infection markers .
all wounds were monitored and photographed as they progressed and wound dimensions were measured with a ruler ( fig .
the location and diagnosis of the ulcer was recorded as well as the presence of any granulation tissue .
clinical investigations performed prior to therapy included markers of infection ( leukocyte count , c - reactive protein and erythrocyte sedimentation rate ) .
a swab from the wound was sent for culture and sensitivity tests before application of the npwt system .
the npwt settings , mode of application , date of initiation and end of npwt , number and date of npwt dressing changes were recorded .
prior to renasys - go npwt treatment , adequate surgical debridement was performed on all wounds to remove any necrotic and infected tissue .
the npwt dressing was cut to fit the size and shape of the wound and the number of pieces used recorded to ensure all pieces were removed at each dressing change .
the wounds were sealed using semi - permeable film drape and a hole was cut in the center of the film .
the soft port was placed directly over the hole in the film and its tubing was connected to the canister tubing .
for all patients , the npwt device was set at continuous or mode with negative pressure of 100 or 120 mmhg .
the pressure settings were dependent on the amount of exudate from the wound and patient 's skin sensitivity since pressures may need to be lower to reduce pain on the skin .
npwt dressing changes were performed every 4872 hours by a trained medical officer or nurse . the number of npwt dressing changes ranged from two to nine dressings , while the duration of npwt treatment was 726 days .
the age of patients in this study ranged from 37 to 66 ( median : 54 ) .
five patients were malays , three indians , and two chinese . complications of dm seen in the study patients included peripheral neuropathy , vasculopathy , nephropathy and diabetic retinopathy . comorbidities which affected the study group included hypertension , hyperlipidemia and peripheral vascular disease .
patient characteristics 
 table 2 shows the renasys - go npwt settings for the patients .
a pressure of 100 mmhg was applied to four of the wounds , while a pressure of 120 mmhg was applied to the remaining six wounds .
wounds were administered npwt for an average of 15.9 days ( range 726 ) while an average of 5.2 npwt dressings ( range 29 ) was used per patient in the study group .
table 3 illustrates the changes in wound size and final outcome of wounds for all patients .
the remaining two patients demonstrated an increase in size of the wound due to repeated debridements .
seven of the 10 wounds healed by a split - thickness skin graft ( stsg ) and three wounds healed by secondary closure .
treatment details and machine settings the average size of the wounds at the beginning of the study was 39.95 cm ( range : 5.00156.00 cm ) , and by the end of the study , the average wound size had reduced to 37.339 cm ( range : 6.00149.80 cm ) .
a 42-year - old indian male presented with a dorsal foot ulcer wagner grade 3 and exposed tendons .
risk factors associated with healing consisted of an 8-year history of type 2 dm and hyperlipidemia .
the patient had previously undergone three surgical wound debridements and ray amputation of the big toe in january 2013 in a different facility where he was offered a below - the - knee amputation .
patient 's dorsalis pedis and posterior tibial pulses were palpable , with ankle brachial index and toe brachial index readings of 1.23 and 0.87 , respectively and a capillary refill timing of < 2 seconds .
the patient 's semmes - weinstein monofilament test was 5/10 with a 24 v reading on the neurothesiometer .
markers of infection were as follows : white blood cell ( wbc ) count of 1210/l , erythrocyte sedimentation rate ( esr ) of 141 mm / hr and c - reactive protein ( crp ) of 138
the markers of wound healing included 14.5% for hemoglobin ( hb ) a1c , 11.6 g / dl for hb and 20
function indicated a level of 54 mol / l for creatinine and 3.7 mmol / l for blood urea nitrogen .
a microbiology test for culture and sensitivity indicated that the following microorganisms were present : proteus mirabilis , enterococcus faecalis and coagulase - negative staphylococcus aureus .
the patient was administered intravenous piperacillin / tazobactam ( tazocin ) and surgical wound debridements were performed .
this was followed by the application of renasys - go npwt dressing with bedside debridements post - operation between dressing changes . by the 17th post - operative day , a microbiology culture test was performed without any growth of microorganisms found .
this was treated with regular dressings and completely healed in the eighth week and gained his ambulatory status ( fig .
( b , c , d , e ) post - operative day 7 , 10 , 12 , 17 respectively .
( f , g , h ) post - ssg week 4 , 6 , 8 respectively . a 65-year - old malay female presented with an ulcer on the left shin .
risk factors associated with healing consisted of a history of more than 10 years of type 2 dm , hyperlipidemia and hypertension .
the markers of healing were > 16.0% for hba1c , 12.0 g / dl for hb and 35
function indicated a level of 105 mol / l for creatinine and 6.6 mmol / l for blood urea nitrogen .
hydrosurgical debridement of the infected ulcer was carried out before application of the renasys - go npwt dressing .
a final debridement along with a stsg was then performed , followed by the npwt application .
the wound was inspected 5 days after the stsg and healed completely after 2 months . the wound area was decreased by 31.00% ( fig .
( d , e ) post - ssg day 5 and week 8 , respectively .
a 42-year - old indian male presented with a dorsal foot ulcer wagner grade 3 and exposed tendons . risk factors associated with healing consisted of an 8-year history of type 2 dm and hyperlipidemia .
the patient had previously undergone three surgical wound debridements and ray amputation of the big toe in january 2013 in a different facility where he was offered a below - the - knee amputation .
patient 's dorsalis pedis and posterior tibial pulses were palpable , with ankle brachial index and toe brachial index readings of 1.23 and 0.87 , respectively and a capillary refill timing of < 2 seconds .
the patient 's semmes - weinstein monofilament test was 5/10 with a 24 v reading on the neurothesiometer .
markers of infection were as follows : white blood cell ( wbc ) count of 1210/l , erythrocyte sedimentation rate ( esr ) of 141 mm / hr and c - reactive protein ( crp ) of 138 mg / l .
the markers of wound healing included 14.5% for hemoglobin ( hb ) a1c , 11.6 g / dl for hb and 20
renal function indicated a level of 54 mol / l for creatinine and 3.7 mmol / l for blood urea nitrogen .
a microbiology test for culture and sensitivity indicated that the following microorganisms were present : proteus mirabilis , enterococcus faecalis and coagulase - negative staphylococcus aureus .
the patient was administered intravenous piperacillin / tazobactam ( tazocin ) and surgical wound debridements were performed .
this was followed by the application of renasys - go npwt dressing with bedside debridements post - operation between dressing changes . by the 17th post - operative day
this was treated with regular dressings and completely healed in the eighth week and gained his ambulatory status ( fig .
( b , c , d , e ) post - operative day 7 , 10 , 12 , 17 respectively .
( f , g , h ) post - ssg week 4 , 6 , 8 respectively .
risk factors associated with healing consisted of a history of more than 10 years of type 2 dm , hyperlipidemia and hypertension .
markers of infection were as such : wbc 11.510/l , esr 53 mm / hr and crp 42
the markers of healing were > 16.0% for hba1c , 12.0 g / dl for hb and 35
renal function indicated a level of 105 mol / l for creatinine and 6.6 mmol / l for blood urea nitrogen .
hydrosurgical debridement of the infected ulcer was carried out before application of the renasys - go npwt dressing .
a final debridement along with a stsg was then performed , followed by the npwt application .
the wound was inspected 5 days after the stsg and healed completely after 2 months .
( d , e ) post - ssg day 5 and week 8 , respectively .
the effectiveness of npwt for diabetic foot wounds is well supported by previous research ( 58 ) .
has shown to achieve comparable results for both chronic and acute wounds ( 9 ) .
the present study is the first one in singapore to explore the effectiveness of this newer system for diabetic lower limb ulcers .
compared to conventional dressings , npwt provides a controlled wound environment that is separate from the external surroundings .
this enables wound healing to occur under clean conditions , with moisture level controlled by altering pressure settings .
hence , the healing of chronic wounds such as diabetic foot ulcers is enhanced by the usage of npwt dressings .
, showing a 49% compared to 7.7% reduction in wound depth and 59% compared to 0.1% reduction in wound volume when diabetic foot ulcers were treated with vac therapy as compared to moist gauze dressings ( 11 ) .
our study showed an average reduction in wound area of 22.4% , with eight out of 10 wounds having a decreased wound area after treatment .
a freshly granulating wound bed indicates that the wound has entered the proliferative stage of wound healing and permits either secondary closure or the usage of other wound closure techniques .
. showed that wounds treated with npwt dressing , either continuous or intermittent , granulated better than those treated using conventional dressing ( 12 ) . in this study , the time required to achieve wound bed preparation for surgical intervention was taken as the time from initiation of renasys - go therapy to the achievement of a continuous and fresh bed of granulation in the wound .
all wounds were able to achieve adequate granulation tissue before closure by secondary healing ( three out of 10 patients ) or by a successful stsg ( seven out of 10 patients ) .
the renasys - go therapy was observed to be beneficial in reducing bacterial infection in the wounds studied .
this potential benefit of npwt was suggested in a swine model study by morykwas et al .
a significant reduction in the bacterial load of inflicted chronic wounds was achieved by the fifth day for those treated with npwt , but required an additional 6 days to reach the same reduced level in wounds untreated with npwt . in our study , culture and sensitivity
tests found colonization of all 10 wounds at the start of npwt ( table 1 ) .
however , after npwt treatment , all 10 wounds showed clearance of bacterial infection , allowing surgical intervention to be undertaken or secondary closure to occur . in this study , the average duration required to complete the npwt was 15.9 days , with a range from 7 to 26 days .
however , in singapore , the cost of renasys - go therapy is relatively high and adds on to patients hospitalization costs . as such , to make this npwt more affordable for our patients , stsg was performed once the wound bed preparation was achieved with sufficient granulation tissue and wound cultures being negative for bacterial growth .
it is also interesting to note that the average length of time taken for our npwt treatment ( 15.9 days ) was shorter than the average length of time taken for other similar conventional treatments ( 23.3 days ) ( 15 ) .
along with the international expert panel on negative pressure wound therapy have recommended a range of npwt settings between 50 and 150 mmhg ( 16 ) .
lower negative pressures may be considered for pain reduction , and higher negative pressures may be considered for high volume of wound exudates ( 16 ) . in our study ,
npwt settings were between 100 mmhg ( four patients ) to 120 mmhg ( six patients ) .
lower negative pressures ( 100 mmhg ) were used for pain reduction and higher negative pressures ( 120 mmhg ) were used for a high volume of wound exudates . limitations of this study includes a low patient number , short term follow - up and lack of comparison of the renasys - go therapy versus other forms of npwt or conventional dressings . with the positive results seen in our case series , we recommend future studies such as a prospective randomized controlled clinical trial comparing the efficacy of renasys - go therapy versus other treatment modalities
compared to conventional dressings , npwt provides a controlled wound environment that is separate from the external surroundings .
this enables wound healing to occur under clean conditions , with moisture level controlled by altering pressure settings .
hence , the healing of chronic wounds such as diabetic foot ulcers is enhanced by the usage of npwt dressings .
, showing a 49% compared to 7.7% reduction in wound depth and 59% compared to 0.1% reduction in wound volume when diabetic foot ulcers were treated with vac therapy as compared to moist gauze dressings ( 11 ) .
our study showed an average reduction in wound area of 22.4% , with eight out of 10 wounds having a decreased wound area after treatment .
a freshly granulating wound bed indicates that the wound has entered the proliferative stage of wound healing and permits either secondary closure or the usage of other wound closure techniques .
morykwas et al . showed that wounds treated with npwt dressing , either continuous or intermittent , granulated better than those treated using conventional dressing ( 12 ) . in this study , the time required to achieve wound bed preparation for surgical intervention was taken as the time from initiation of renasys - go therapy to the achievement of a continuous and fresh bed of granulation in the wound .
all wounds were able to achieve adequate granulation tissue before closure by secondary healing ( three out of 10 patients ) or by a successful stsg ( seven out of 10 patients ) .
the renasys - go therapy was observed to be beneficial in reducing bacterial infection in the wounds studied .
this potential benefit of npwt was suggested in a swine model study by morykwas et al .
a significant reduction in the bacterial load of inflicted chronic wounds was achieved by the fifth day for those treated with npwt , but required an additional 6 days to reach the same reduced level in wounds untreated with npwt . in our study , culture and sensitivity
tests found colonization of all 10 wounds at the start of npwt ( table 1 ) .
however , after npwt treatment , all 10 wounds showed clearance of bacterial infection , allowing surgical intervention to be undertaken or secondary closure to occur .
in this study , the average duration required to complete the npwt was 15.9 days , with a range from 7 to 26 days .
however , in singapore , the cost of renasys - go therapy is relatively high and adds on to patients hospitalization costs . as such , to make this npwt more affordable for our patients , stsg was performed once the wound bed preparation was achieved with sufficient granulation tissue and wound cultures being negative for bacterial growth .
it is also interesting to note that the average length of time taken for our npwt treatment ( 15.9 days ) was shorter than the average length of time taken for other similar conventional treatments ( 23.3 days ) ( 15 ) .
along with the international expert panel on negative pressure wound therapy have recommended a range of npwt settings between 50 and 150 mmhg ( 16 ) .
lower negative pressures may be considered for pain reduction , and higher negative pressures may be considered for high volume of wound exudates ( 16 ) . in our study ,
npwt settings were between 100 mmhg ( four patients ) to 120 mmhg ( six patients ) .
lower negative pressures ( 100 mmhg ) were used for pain reduction and higher negative pressures ( 120 mmhg ) were used for a high volume of wound exudates .
limitations of this study includes a low patient number , short term follow - up and lack of comparison of the renasys - go therapy versus other forms of npwt or conventional dressings . with the positive results seen in our case series , we recommend future studies such as a prospective randomized controlled clinical trial comparing the efficacy of renasys - go therapy versus other treatment modalities .
in this study , the renasys - go npwt system has been shown as beneficial in the treatment of diabetic lower limb ulcers and wounds , which may include wounds with exposed tendons , fascia or bone after surgical debridement .
in addition , this npwt system was able to prepare all wounds for closure via stsg or secondary healing by promoting sufficient granulation tissue and by reducing bacterial infection of the wounds in a reasonable amount of time ( average of 15.9 days ) .
the authors declare that they have no conflict of interest and have not received any funding or benefits from industry to conduct this study .
 introductionthis case series aims to study the effectiveness of renasys - go negative pressure wound therapy system in the healing of diabetic lower limb ulcers.materials and methodsan electronic vacuum pump ( renasys - go , smith & nephew gmbh ) was used to apply negative pressure wound therapy on wounds , with pressure settings determined according to clinical indication . 
 changes in wound dimension , infection status and duration of treatment were recorded over the course of renasys - go therapy in 10 patients with diabetic lower limb ulcers.resultshealing was achieved in all wounds , three by secondary closure and seven by split - thickness skin grafting . eight wounds showed a reduction in wound size . 
 the average duration of treatment with renasys - go therapy was 15.9 days , and all wounds showed sufficient granulation and were cleared of bacterial infection at the end of therapy.conclusionsrenasys - go therapy may be beneficial in the treatment of diabetic lower limb ulcers and wounds . in this study , which included wounds presenting as post - surgery ray amputation , metatarsal excision wounds , post - debridement abscesses and ulcers , the renasys - go therapy prepared all wounds for closure via split - thickness skin grafting or secondary healing by promoting granulation tissue and reducing bacterial infection in approximately 2 weeks . 
Materials and methods
Indications
Study protocol
Application techniques
Results
Case study 1
Case study 2
Discussion
Wound size reduction
Promotion of granulation tissue
Reduction of bacterial infection
Length of time
Pressure levels
Study limitations
Conclusion
Conflict of interest and funding