S.R Vacuum suction Cannula for the management of atonic PPH

Introduction: As per the WHO estimate 303,000 maternal deaths were reported globally in the year 2015. Low resource countries like Sub-Saharan Africa and Southern Asia contributed 99% of maternal deaths.In developing countries, postpartum hemorrhage (PPH) remains the leading cause for maternal deaths, amounting to 1, 27,000 (60%) deaths every year. Fifty percent of these women die due to atonic PPH. Majority of these deaths occur in peripheral centers with sub-optimal facilities.Even though some risk factors like obstructed prolonged labor, accidental hemorrhage, and big babies are known to cause atonic PPH, it is not very clear why some women develop atonic PPH and why some women do not. For the same reason this problem cannot be predictable.

The only management strategy even today is ‘watchful expectancy’ and act immediately when the problem develops. Simpler techniques like uterine massage, uterotonics drugs, and uterine packing and balloon tamponadecan be practiced in low resource settings. Techniques like B-Lynch suturing, stepwise devascularization, internal iliac ligation and uterine artery embolization are available at higher medical centers. These higher techniques are not within the reach of every parturient woman when simpler techniques fail.

In low resource settings unpredictable sudden massive bleeding makes it difficult to organize competent manpower, compatible blood and transport to higher medical center. Many times mothers die on roads while being transported to higher medical centers due to hypovolemic shock. In some women the speed with which the hemorrhage kills the mother is so rapid, that thewomen succumb to death just within 1-1.5 hours after the onset of bleeding . The rapidity with which some women slip in to coagulation failure and multi organ dysfunction syndrome from hemorrhagic shock is alarming. Because of these complex reasons the maternal mortality is not coming down in low resource settings⁹. There is every need for a simpler and sure technique which can stop bleeding, or at least stop bleeding temporarily to buy some time to tide over the crisis.

Concept: Creating negative pressure inside the uterine cavity with a specially designed uterine cannula, results in shrinking of uterus which can assist the natural physiological process of contraction and retraction to stop atonic postpartum hemorrhage.

Methods: Sixteen singleton pregnant women who had normal vaginal delivers and 4 women who underwent caesarean sections,who developed atonic postpartum hemorrhage, and who didnot respond well for medical managementwere included in this study. All the women received 10units of oxytocin IM at the appearance of anterior shoulder, 5units of intra venous oxytocin after the delivery of placenta, and then uterine massage. Inj. Carboprost 125micgmsIM was also given when the bleeding did not stop. SR cannula was applied in all these women when all medical methods failed.

Description of uterine vacuum retraction system:Consists of,

1.SR suction cannulas for PPH after vaginal delivery:Two sizes of vaginal cannulas are made measuring 25cm long, and have auterine angle. Uterine portion measures 14mm long, and with 24mm and 18mm in diameter. Vaginal portion measures 10cm long with 12mm in diameter. The outer portion is the nipple of the cannula to be connected to suction machine with tubing. Perforations on fundal portion are large and longitudinal, and on cervical portion they are round and small. Vaginal portion do not have any perforations (Fig.1 A and B).

2.SR suction cannulas for atonic PPH at caesarean delivery: These are two shorter cannulas measuring 14cm long. Cannula with 12mm diameter is meant for undilated cervix, and the cannula with 18mm diameter is meant for dilated cervix.

3. Thick walled, not easily collapsible flexible plastic suction tube (Fig 1C). 4. High vacuum suction machine, or vacuum suction pump which can produce negative pressure up to 650mm Hg. within 1mnt.

In case of vaginal delivery:When atonic bleeding does not stop by all routine medical measures, women should be kept in lithotomy position, and the bladder should be catheterized.Blood clots should be removed from uterine cavity by bimanual compression.Under good source of light with wide blade vaginal speculum application, the anterior lip of cervix should be grasped with sponge holding forceps, and the uterine end of the cannula should be inserted in to the uterine cavity up to the level of fundus. The outer end of the cannula should be connected to the suction machine throughtubing. The left palm supporting the fundus per abdomen, right fingers grasp the outer end of the cannula, and push it gentlyup to the fundus. Keeping the cannula in this position (to prevent slipping out), suction machine should be put on, and a negative pressure of 650mmhg should be created, and maintained for 10mnts.Then the suction machine was put off. This makes the cannula to get fixed in this position due to sucking of soft cervical tissues in to the perforations on cervical portion of the cannula. Negative pressure should be applied for 10mts every hour for 3hrs.

Fig 2:(A)Vacuum retraction of uterus using high vacuum suction machinefor atonic PPH after vaginal delivery.(B)Contraction and firm retraction of uterus with rougosities on the surfaceat caesarean section

After this, the negative pressure should be created whenever there is recurrence of bleeding. Twenty units Pitocin in 5% dextrose, 60drops/mint infusion, can also be used whenever needed. The cannula should bekept in position as long as the threat for recurrence of bleeding expected,or even up to 24hrs.

Cannula removal:After the procedure,when we try to pull the cannula, it willnot come out easily. This is because of the formation of temporary adhesions due to sucking of soft cervical tissues in to perforations of the cervical portion of the cannula.Cannula can be removed easily after gentle separation of these adhesions by finger manipulation.

In case of caesarean section:One end of the suction tube should be connected to the cannula. The other end should beinserted through the uterine wound and brought outside the vagina. If cervix is not well dilated, the smaller size cannula can be used. The outer end of the suction tube should beconnected to the suction machine. After keeping the cannula in proper (tip at the level of fundus) position, and after keeping the cut edges of the wound close together, negative pressure should be applied. Uterine wound should be closed when negative suction pressure is working.

Mechanism how it works?

Fig 3: Mechanisms how negative pressure inside the uterine cavity stops atonic bleeding.

Results from our study: the complete cessation of bleeding which was associated with contraction and firm retraction of uterus was observed in all women within 4mns after initiation of procedure. None of the women had recurrence of bleeding after 3hrs of initiation of procedure, and there was no need for repeat suction. All the women were clinically stable during the procedure. The amount of blood collected in suction bottle ranged from 150ml to 250ml. At caesarean section, we could observe contraction and firm retraction of uterus with the formation of rougosities on the surface(Fig 2 B).

Discussion: Currently the balloon tamponade is being widely advocated as an affordable alternative to blood loss management in severe atonic postpartum hemorrhage refractory to uterotonic therapy⁹. In this technique,the water filled balloon expands the uterine cavity and applies constant pressure (more than the systolic blood pressure) on sinusoids to stop bleeding¹⁰. The mechanism of action in this technique is against the natural physiological mechanism of contraction and retraction. It requires some time to organize this balloon tamponade system. This technique cannot be used when tamponade test is negative¹¹. When the woman is bleeding profusely, even this few minutes time is very precious and critical.

In contrast the mechanism involved in vacuum constriction, the negative pressure created inside the uterine cavity results in physical constriction of uterus which assists the natural physiological process of contraction and retraction. When negative pressure applied, the soft cervical tissues around the cervical portion of the cannula get sucked in to the perforations of the cannula. This results in closed uterine cavity. Further application of negative pressure results in in uniform constriction, contraction and firm retraction ofuterus(Fig 3). As the blood circulation to uterus is not interfered, the utero tonic drugs continue to act and maintain the process of contraction and retraction. Blood collected in the uterine cavity get sucked and collected in to the suction bottle and helps to measure the blood loss correctly. As this procedure needs little time and minimal skills, even maternity nurses can be trained and the bleeding can be stopped without any delay

SR suctioncannula techniqueis a properly designed physical method, and it will not failto stop atonic bleeding.Hundreds of cannulas reached obstetricians in this country, and they are using.No failures were reported when properly used. We have few reports that, SR cannula could stop bleeding even in women with coagulation failure.

Conclusions: Vacuum constriction of uterus is highly promising, simple, effective technique, which can stop atonic bleeding with in 4mnts, and helps to prevent maternal death and preserve fertility function in low resource settings. As this is highly cost effective, this can be used in any setting. Further studies are going on to include SR cannula in the active management of third stage of labor, to minimize blood loss in every parturient woman.

This article was published in IOSR Journal of Dental and Medical Sciences (IOSR-JDMS) in November 2014.

This paper was awarded FOGSI Dr.C.S.Dawan prize at AICOG-2015, Chennai.

This paper was awarded KFOG President Gold medal for the year 2015.

This paper is the competition paper for ‘CORION AWARD’for the year 2017

This cannula got patent registered in september 2015.

Dr H. Samartha ram

The author is HOD. Director, senior consultant, obstetrics and gynecology, Sandhyaram hospital, katampazhi puram, palakkad, kerala. He is a member Editorial Board, , Gynecologist at Specialty Medical Dialogues.